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Sample records for absorption spectrometry determination

  1. Determination of cadmium in aluminium by atomic absorption spectrometry

    A direct method for the determination of cadmium in elemental aluminium is described. Metal samples are dissolved in diluted hydrochloric acid and cadmium is determined by atomic absorption spectrometry in an air-acetylene flame. Interference by non-specific absorption observed at the analytical wavelength incorrected for by means of a non-absorbing line emitted by the hollow-cathode lamp. Relatively large amounts of arsenic do not interfere. The minimun determinable concentration of cadmium for this procedure is 2-3 ppm, expressed on aluminium basis. (author)

  2. Determination of metals in atmospheric particulates using atomic absorption spectrometry

    Nineteen trace metals in atmospheric samples have been determined by atomic absorption spectrometry, using a graphite furnace for most elements. Paper filters have been used to collect air samples. The sample preparation procedure involves the removal of organic matter and the conversion of the metals to soluble salts by ashing the filters in an oxygen plasma at 125 deg C for 6 h. and by subsequent dissolution in HN03HCl solution. The sensitivities achieved are in the range of 2,5.10-5 and 6,3.10-3 μg/m3, for an air volume of 2000 m3. (author)

  3. Simultaneous Atomic Absorption Spectrometry for Cadmium and Lead Determination in Wastewater: A Laboratory Exercise

    Correia, Paulo R. M.; Oliveira, Pedro V.

    2004-01-01

    The simultaneous determination of cadmium and lead by multi-element atomic absorption spectrometry with electrochemical atomization is proposed by employing a problem-based approach. The reports indicate that the students assimilated the principles of the simultaneous atomic absorption spectrometry (SIMAAS), the role of the chemical modifier, the…

  4. Determination of gold by chemical hydride generation atomic absorption spectrometry

    Complete text of publication follows. The chemical vapour generation (CVG) of transition and noble metals opens a novel route for introduction of these elements into atomic spectrometric sources. It can be accomplished by merging an acidic sample with tetrahydroborate reductant solution (Y. L. Feng et al., J. of Anal. At. Spectrom., 20 (2005) 255-265). There have been some studies for determination of Au; however, only mg L-1 levels of gold have been determined by CVG - Atomic Absorption Spectrometry (AAS) (G. Ertas et al., Applied Spectroscopy, 60 (2006) 423-429). Volatile Au species were generated in flow injection arrangement from acid environment in presence of surfactants. The core of the system is a mixing manifold based on 3 concentric capillaries (T. Matousek et al., J. of Anal. At. Spectrom., 18 (2003) 487-494) protruding into the glass gas-liquid separator (glass, volume 3 ml). Optimum flow rate of Ar as a carrier gas was found at 240 mL/min. The study of generation parameters as well as the use of reaction modifiers-surfactants and dithiocarbamate- will be presented. Quartz tube multiatomizer for AAS was employed for atomization. Atomization conditions including composition of carrier gases and their flow rates and atomization temperature were optimized. 900 deg C was found as the optimum atomization temperature; over 900 deg C, peak area of Au signal decreased; in addition, peak shape was altered. A sharp maximum of 6 mL/min oxygen as the outer gas was observed. Another important point was that hydrogen-rich atmosphere caused signal depression. Analytical performance of this approach to generation and atomization will be discussed and perspectives of its future will be outlined. This work was supported by the GA ASCR (grant No. A400310507 and IAA400310704) and Institute of Analytical Chemistry of the ASCR, v.v.i. (project no. AV0Z40310501). This work also was supported from OYP (Faculty Development Program) from the Middle East Technical University

  5. Quantitative determination of impurities in nuclear grade aluminum by Flame-Atomic Absorption Spectrometry

    The paper deals with quantitative determination of impurity elements in nuclear grade aluminum, used as fin tubes in research reactors, by Flame-Atomic Absorption Spectrometry (F-AAS). The results have been compared with those obtained by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) method. Experimental conditions used in both the methods are given in the paper. (author)

  6. Cinchocaine hydrochloride determination by atomic absorption spectrometry and spectrophotometry.

    Abdel-Ghani, Nour T; Youssef, Ahmed F A; Awady, Mohamed A

    2005-05-01

    Two sensitive spectrophotometric and atomic absorption spectrometric procedures have been developed for determination of cinchocaine hydrochloride (Cin.Cl) in pure form and in pharmaceutical formulation. The spectrophotometric method was based on formation of an insoluble colored ion-associate between the cited drug and tetrathiocyanatocobaltate (CoTC) or hexathiocyanatochromate (CrTC) which dissolved and extracted in an organic solvent. The optimal experimental conditions for quantitative extraction such as pH, concentration of the reagents and solvent were studied. Toluene and iso-butyl alcohol proved to be the most suitable solvents for quantitative extraction of Cin-CoTC and Cin-CrTC ion-associates with maximum absorbance at 620 and 555 nm, respectively. The optimum concentration ranges, molar absorptivities, Ringbom ranges and Sandell sensitivities were also evaluated. The atomic absorption spectrometric method is based on measuring of the excess cobalt or chromium in the aqueous solution, after precipitation of the drug, at 240.7 and 357.9 nm, respectively. Linear application ranges, characteristic masses and detection limits were 57.99-361.9, 50.40 and 4.22 microg ml(-1) of Cin.Cl, in case of CoTC, while 37.99-379.9, 18.94 and 0.81 microg ml(-1) in case of CrTC. PMID:15910814

  7. Micro-determination of ytterbium with electrothermal atomic absorption spectrometry

    This communication reports the use of a pyrolytic graphite coated tube, lined with tantalum-tungsten, and a local made atomic absorption spectrometer (Model WFD-Y3) for the determination of small amount Yb in pure Y2O3 and mixed rare earth oxides. It is found that the method proposed is sensitive, reproducible and simple in manipulation. Even as low as 0.2 μg Yb in one gram sample (n x 10-7) can be determined directly without pre-concentration. It is found experimentally that the optimum condition for drying is at 150 deg C. for 20 sec, ashing at 1000 deg C. for 20 sec and atomization at 2770 deg C. for 12 sec. Within the range 1.0-18ng Yb/ml the calibration curve of Yb is linear. Before injecting into the tube, the acidity of the sample solution should be ajusted to 0.1 to 2 M with nitric or hydrochloric acid. For 5ng Yb/ml, Al(III), Ca(II) and La(III) interference, when their amount present is 50 μg/ml or more. On the other hand, Cu(II), Fe(III), Mg(II), K(I) and Y(III) in amount up to 1 mg/ml do not interfere

  8. Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

    Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne;

    1986-01-01

    A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve...

  9. Determination of antimony by using tungsten trap atomic absorption spectrometry

    An electrically heated tungsten coil was used as a trap in the determination of antimony. The technique consists of three steps. Initially, SbH3 is formed by hydride generation procedure; then the analyte species in vapor form are transported to W-coil trap heated at 370 deg. C. Following the preconcentration step, the trap is heated to 895 deg. C; analyte species are revolatilized and transported to the flame-heated quartz atom cell where atomization and the formation of signal take place. The experimental parameters were optimized both for trap and no-trap studies. The most important experimental parameters are concentrations of HCl and NaBH4 solutions, H2 and Ar gas flow rates, and collection and revolatilization temperatures of W-coil. Accuracy was tested using a certified reference material, waste water EU-L-1. Limit of detection for the system is 16 ng l-1 using a sample of 36 ml collected in 4.0 min. Enhancement factor in sensitivity was 17

  10. Evaluation of a method for the determination of chromium in urine by atomic absorption spectrometry

    A method for the determination of chromium in urine by atomic absorption spectrometry, using electrothermic atomization with pyrolytic graphite tubes, is proposed. The determinations are performed by standard addition. The method is applicable to biologic monitoring of populations with different degrees of exposition. It is also used in the analysis of chromium in sediments. Results of chromium in urine of a population group non-exposed to the metal are presented. 11 refs

  11. Direct determination of selenoproteins in polyvinylidene difluoride membranes by electrothermal atomic absorption spectrometry

    Sidenius, U; Gammelgaard, Bente

    2000-01-01

    A method for the direct determination of selenoproteins in plastic membranes after protein separation by gel electrophoresis was developed. Quantification was based on the determination of the selenium content of the proteins by electrothermal atomic absorption spectrometry (ET-AAS) after manual...... were excised and chemical modifier was added on top of the excised membrane prior to atomic absorption measurement. Acceptable linearity was achieved in the range 2-10 ng Se, corresponding to selenium concentrations close to 1 mg/L, when aqueous solutions of selenomethionine standard as well as...

  12. Determination of lead traces in water and liqueurs by derivative atom trapping flame atomic absorption spectrometry

    Sun, H. [Department of Chemistry, Hebei University, Baoding, 071002 (China); Yang Lili [Department of Chemistry, Hebei University, Baoding, 071002 (China); Zhang Deqiang [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing (China); Wang Weixiao [Department of Chemistry, Hebei University, Baoding, 071002 (China); Sun Jianmin [Department of Chemistry, Hebei University, Baoding, 071002 (China)

    1997-07-01

    A new method for the direct determination of lead traces using derivative atom trapping flame atomic absorption spectrometry (DAT-FAAS) with an improved water-cooled stainless steel trapping equipment in an air-acetylene flame was investigated. The optimum conditions concerning the sensitivity were studied. For a 1 min collection, the characteristic concentration (given as derivative absorbance of 0.0044) and the detection limit (3s) were 1.4 ng/mL and 0.27 ng/mL, respectively. This is 361 and 74-fold better than those of the conventional flame atomic absorption spectrometry (FAAS) and comparable to those of graphite furnace atomic absorption spectrometry (GFAAS). The detection limit and sensitivity of DAT-FAAS for a 3 min collection time were 2 and 3 orders of magnitude higher than those of conventional FAAS. The present method was applied to the determination of lead in water and liqueur samples with a recovery range of 94-108% and a relative standard deviation of 3.5-5.6%. (orig.). With 5 figs., 5 tabs.

  13. Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry

    A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO3)2 was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 μg g-1 of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

  14. Optimization of trace molybdenum content determination in human nails by graphite furnace atomic absorption spectrometry

    The accurate determination of molybdenum (Mo) in biological materials is of considerable importance in medical science because of the essential role played by this element in human metabolism. Molybdenum is a component of enzymes responsible for the initial stages of nitrogen, carbon and sulfur metabolism of plants, animals and humans. This element is usually determined by neutron activation analysis (NAA) in variety of samples, but direct measurement of low levels of molybdenum in biological samples by NAA is difficult. Recently instrumental analysis procedures such as atomic absorption spectrometry (AAS) have been used in clinical measurements for determination of many trace elements in the biological samples. These techniques are much simpler and cheaper than NAA. In this paper we are reporting a method of sample preparation for determining molybdenum by using graphite furnace atomic absorption spectrometry (GF-AAS). This method is the most readily available technique for determination of molybdenum at the ng/g level in biological samples. It can be used for the routine hospital laboratory determination of molybdenum and has appropriate sensitivity and simplicity. The best and reliable results for molybdenum analysis was achieved by digestion of nails in HNO3 2 N and was determined in the range from 0.11 to 5.10 μg/g

  15. Determination of serum lithium: comparison between atomic emission and absorption spectrometry methods

    Carlos Elielton do Espírito Santo

    2014-02-01

    Full Text Available Introduction: The therapeutic monitoring of lithium, through concentration measurements, is important for individual dose adjustment, as a marker of treatment adherence and to prevent poisoning and side effects. Objectives: Validate and compare two methods - atomic emission and atomic absorption - for the determination of lithium in serum samples. Methodology: Parameters such as specificity, precision, accuracy, limit of detection (LOD and linearity were considered. The atomic absorption spectrometer was used, operating in either emission or absorption mode. For the quantitative comparison of 30 serum samples from patients with mood disorder treated with lithium, the results were submitted to Student's t-test, F-test and Pearson's correlation. Results: The limit of quantification (LOQ was established as 0.05 mEq/l of lithium, and calibration curves were constructed in the range of 0.05-2 mEq/l of lithium, using aqueous standards. Sample preparation time was reduced, what is important in medical laboratory. Conclusion: Both methods were considered satisfactory, precise and accurate and can be adopted for lithium quantification. In the comparison of quantitative results in lithium-treated patients through statistical tests, no significant differences were observed. Therefore the methods for lithium quantification by flame atomic absorption spectrometry (FAAS and flame atomic emission spectrometry (FAES may be considered similar.

  16. Exploiting flow Injection and sequential injection schemes for trace metal determinations by electrothermal atomic absorption spectrometry

    Hansen, Elo Harald

    Determination of low or trace-level amounts of metals by electrothermal atomic absorption spectrometry (ETAAS) often requires the use of suitable preconcentration and/or separation procedures in order to attain the necessary sensitivity and selectivity. Such schemes are advantageously executed in...... compensated by superior performance and versatility. In fact, two approaches are conceivable: The analyte-loaded ion-exchange beads might either be transported directly into the graphite tube where they are pyrolized and the measurand is atomized and quantified; or the loaded beads can be eluted and the...

  17. Determination of tetraalkyllead compounds in gasoline by liquid chromatography-atomic absorption spectrometry

    Messman, J.D.; Rains, T.C.

    1981-01-01

    A liquid chromatography-atomic absorption spectrometry (LC-AAS) hybrid analytical technique is presented for metal speciation measurements on complex liquid samples. The versatility and inherent metal selectivity of the technique are Illustrated by the rapid determination of five tetraalkyllead compounds in commercial gasoline. Separation of the individual tetraalkyllead species is achieved by reversed-phase liquid chromatography using an acetonitrile/water mobile phase. The effluent from the liquid Chromatograph Is introduced directly into the aspiration uptake capillary of the nebulizer of an air/acetylene flame atomic absorption spectrometer. Spectral interferences due to coeluting hydrocarbon matrix constituents were not observed at the 283.3-nm resonance line of lead used for analysis. Detection limits of this LC-AAS hydrid analytical technique, based on a 20-??L injection, are approximately 10 ng Pb for each tetraalkyllead compound.

  18. Determination of lithium in coloured alcoholic beverages by atomic absorption spectrometry

    Complete text of publication follows. Lithium was first found in ashes from wine in 1878, and its presence was later confirmed by spectroscopy, but its determination in wine and beverages is not well documented, unlike the extensive research reported on other metals. Several methods can be implemented for determination of lithium, involving the use of atomic spectroscopy techniques. This paper reports on an analytical optimization to determine lithium by atomic absorption spectrometry (AAS). Good results in reproducibility, accuracy and precision were obtained. No significant interference was found. The method was applied for determination of lithium in six rum samples, eight brandy samples, four vermouth samples, eight whisky samples and two bourbon samples. The value of lithium content in samples ranges from 0,33 to 1,48 μg/ml. Recovery experiments were carried out in order to evaluate the accuracy of the method in samples determination. The values obtained ranges from 95,71% to 98%. The precision of the method in that samples determination was evaluated through variation coefficients. The values obtained ranges from 7,2% to 2,5%. The results have been statistically compared with those obtained using the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP/AES) and reaches a 95% level of significance.

  19. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L- 1 HNO3 solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L- 1 and 36.4 mg L- 1, respectively. The repeatability of the results expressed as relative standard deviation was typically determination of sulfur in milk (194 ± 10 mg kg- 1), egg white (2188 ± 29 mg kg- 1), mineral water (31.0 ± 0.9 mg L- 1), white wine (260 ± 4 mg L- 1) and red wine (82 ± 2 mg L- 1), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L- 1).

  20. Determination of Trace Selenium in Electrolytic Manganese by Graphite Furnace Atomic Absorption Spectrometry

    YAO Jun; ZHOU Fang-qin; MA Cheng-jin; TUO Yong; LIU Jian-ben; WU Zhu-qin; TAN Zhu-zhong

    2003-01-01

    The effects of four types of graphite tube and five matrix modifiers on the determination of selenium by graphite furnace atomic absorption spectrometry were compared.The results show that platform thermolysis coat graphite tube and magnesium nitrate and cobaltco as matrix modifer can get a high sensitivity and a good recovery.The optimized working conditions and interference in the determination were invesigated.This result is consistent with that of XRF.The recovery is from 100.8 % to102.2 %,the relative standard deviation is from 3.47% to 5.56 % (n=9),and the detection limit of selenium is 378 pg (C=44.5μg/g to 97.3μg/g.).The proposed method can be applied to the rapid determination of selenium in electrolytic manganese.

  1. Preconcentration of Vanadium(Ⅴ) on Crosslinked Chitosan and Determination by Graphite Furnace Atomic Absorption Spectrometry

    2002-01-01

    A new method is proposed for the preconcentration of vanadium(Ⅴ) with crosslinked chitosan (CCTS) and determination by graphite furnace atomic absorption spectrometry (GFAAS). The adsorption rate of vanadium(Ⅴ) by CCTS was 97% at pH 4.0, and vanadium(Ⅴ) was eluted from crosslinked chitosan with 2 mL 2.0 mol*L-1 chlorhydric acid and determined by GFAAS. The detection limit (3σ,n=7) for vanadium(Ⅴ) was 4.8×1 0-12g and the relative standard deviation (R.S.D) at concentration level of 2.6 μg*L-1 is less than 3.6%. The method shows a good selectivity and high sensitivity, and it was applied to determination of vanadium(Ⅴ) in oyster and water samples. The analytic recoveries are (97±5)%.

  2. Alternative approaches to correct interferences in the determination of boron in shrimps by electrothermal atomic absorption spectrometry

    The aim of this study is to propose alternative techniques and methods in combination with the classical chemical modification to correct the major matrix interferences in the determination of boron in shrimps. The performance of an internal standard (Ge) for the determination of boron by the simultaneous multi-element atomic absorption spectrometry was tested. The use of internal standardization increased the recovery from 85.9% to 101% and allowed a simple correction of errors during sampling preparation and heating process. Furthermore, a new preparation procedure based on the use of citric acid during digestion and dilution steps improved the sensitivity of the method and decreased the limit of detection. Finally, a comparative study between the simultaneous multi-element atomic absorption spectrometry with a longitudinal Zeeman-effect background correction system, equipped with a transversely-heated graphite atomizer and the single element atomic absorption spectrometry with a D2 background correction system, equipped with an end-heated graphite atomizer was undertaken to investigate the different behavior of boron in both techniques. Different chemical modifiers for the determination of boron were tested with both techniques. Ni-citric acid and Ca were the optimal chemical modifiers when simultaneous multi-element atomic absorption spectrometry and single-element atomic absorption spectrometry were used, respectively. By using the single-element atomic absorption spectrometry, the calculated characteristic mass was 220 pg and the calculated limit of detection was 370 μg/kg. On the contrary, with simultaneous multi-element atomic absorption spectrometry, the characteristic mass was 2200 pg and the limit of detection was 5.5 mg/kg. - Highlights: • New approaches were developed to cope with interferences of B determination by ETAAS • Ge was used as internal standard for the determination of B by simultaneous ETAAS • Citric acid was used during digestion

  3. Study on the application of cold vapor atomic absorption spectrometry and hydride generation atomic absorption spectrometry for the determination of Hg and As traces in sea water samples

    The trace amount of total mercury (Hg) and arsenic (As) in sea water samples were quantitatively determined by using the Atomic Absorption Spectrometry connected with the hydride generation technique (HG-AAS) for As, and with the cold vapour technique (CV-AAS) for Hg. The experiments were carried out at room temperature on a Hydride System Module (HS55) combined with an Atomic Absorption Spectrometer (VARIO 6, Analytik Jena AG). The effect of reductants concentration, and that of matrix on the absorption intensity of each analyzed element was studied in details. The sea water sample after fitrating through a membrane with 0.45(μm-hole size was pre-treated with an oxidant or an reductant to obtain the identical medium. The absorption intensity of each element was then measured on the VARIO-6 under the optimum parameters for spectrometer such as: maximum wavelength, current of hollow cathode lamp, and that for hydride system such as cell temperature, speed of peristaltic pump, pump time, reaction time and rewash time, ect. The analytical procedures were set-up and applied for the determination of these above mentioned elements in the synthesized sea water sample and in the real sea water samples with high precision and accuracy. (author)

  4. Determination of trace elements in ground water by two preconcentration methods using atomic absorption spectrometry

    This is a comparative study between two different methods of preconcentration done to separate the trace elements cadmium, nickel. chromium, manganese, copper, zinc, and lead in drinking (ground) water samples taken from different locations in Gezira State, central Sudan (the map); these methods are (coprecipitation) with aluminium hydroxide and by Ammonium Pyrrolidine Dithiocarbamate (APDC) using Methyl Isobutyl Ketone (MIBK) as an organic solvent; and subsequent analysis by Atomic Absorption Spectrometry (AAS) for both methods. The result of comparison showed the superiority of the (APDC) coprecipitation method over the aluminium hydroxide coprecipitation method in the total percentage recoveries of the studied trace elements in drinking (ground) water samples, such results confirm previous studies. This study also involves direct analysis of these water samples by atomic absorption spectrometry to determine the concentrations of trace elements Cadmium, Nickel, Chromium, Manganese, Copper, Zinc and Lead and compare it to the corresponding guide line values described by the World Health Organization and the maximum concentrations of trace elements in drinking water permitted by the Sudanese Standards and Metrology Organizations (SSMO), where the concentrations of some elements in some samples were found to be different than the described values by both of the organizations. The study includes a trial to throw light on the effect of the proximity of the water samples sources to the Blue Nile river on its trace elements concentrations; no relation was proved to exist in that respect.(Author)

  5. Determination of vanadium in mussels by electrothermal atomic absorption spectrometry without chemical modifiers

    Saavedra, Y.; Fernandez, P. [Centro de Control do Medio Marino, Peirao de Vilaxoan s/n, Vilagarcia de Arousa, 36611 Pontevedra (Spain); Gonzalez, A. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Quimica, 15706, Santiago de Compostela (Spain)

    2004-05-01

    A method was developed for the quantitative determination of total vanadium concentration in mussels via electrothermal atomic absorption spectrometry (ETAAS). After the microwave digestion of the samples, a program using temperatures of 1600 C and 2600 C for ashing and atomization respectively, without any matrix modifiers, allowed us to obtain results that were satisfactory since they agreed closely with certified reference material values. The detection limit was 0.03 mg kg{sup -1} (dry weight), indicating that the method is suitable for the analysis of mussel samples. This determination was compared with matrix modifiers that have been reported previously. The method was applied to various cultivated and wild mussels from the Galician coast, yielding levels below 1 mg kg{sup -1} (wet weight). (orig.)

  6. Electrochemical preconcentration and hydride generation methods for trace determination of selenium by atomic absorption spectrometry

    The use of atomic absorption spectrometry in combination with two different preconcentration/separation techniques for the determination of trace concentrations of selenium is described. Electrochemical preconcentration onto a platinum electrode with a subsequent atomization of selenium is discussed briefly. Several parameters are considered such as the presence of depolarizers, and the temperature of the electrolyzed solutions. Special attention is payed to the efficiency of the atomization step, and a method to improve this is proposed. Applications of the technique to real samples are also reported. Secondly, the separation of the selenium as the volatile selenium hydride from the sample solution is considered. Several papers in this thesis deal with commonly occurring interferants as nickel and copper and with ways of minimizing or avoiding the interferring effects, whereas other papers relate to more theoretical aspects of the hydride generation process. New methods for the determination of selenium in technical samples with high contents of nickel and copper are also presented

  7. Determination of molybdenum in silicates through atomic absorption spectrometry using pre-concentration by active carbon

    An analytical procedure for molybdenum determination in geological materials through Atomic Absorption Spectrometry, after pre-concentration of the Mo-APDC complex in activated carbon, has been developed, which is needed in order to reduce the dilution effect in the sample decomposition. During the development of this method the influence of pH, the amount of APDC for complexation of Mo and the interference of Fe, Ca, Mn, Al, K, Na, Mg and Ti were tested. It was shown that none of these causes any significant effect on the Mo determination proposed. The results of the analysis at the international geochemical reference samples JB-1 (basalt) and GH (granite) were very accurate and showed that the detection limit in rocks (1,00g) is 0,6 ppm, when using sample dilution of 1 ml and microinjection techniques. (author)

  8. The direct determination of HgS by thermal desorption coupled with atomic absorption spectrometry

    Coufalík, Pavel; Zvěřina, Ondřej; Komárek, Josef

    2016-04-01

    This research was aimed at the direct determination of HgS in environmental samples by means of thermal desorption coupled with atomic absorption spectrometry. Operating parameters of the apparatus used for thermal desorption (including a prototype desorption unit) are described in this work, as well as the procedure for measuring mercury release curves together with an evaluation of the analytical signal including two methods of peak integration. The results of thermal desorption were compared with HgS contents obtained by sequential extraction. The limits of quantification of the proposed method for the selective determination of the black and red forms of HgS were 4 μg kg- 1 and 5 μg kg- 1, respectively. The limit of quantification of red HgS in soils was 35 μg kg- 1. The developed analytical procedure was applied to soil and sediment samples from historical mining areas.

  9. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L{sup −1} HNO{sub 3} solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L{sup −1} and 36.4 mg L{sup −1}, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93–105% with the repeatability in the range of 4.1–5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg{sup −1}), egg white (2188 ± 29 mg kg{sup −1}), mineral water (31.0 ± 0.9 mg L{sup −1}), white wine (260 ± 4 mg L{sup −1}) and red wine (82 ± 2 mg L{sup −1}), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L{sup −1}). - Highlights: • HR-CS FMAS technique was used for sulfur measurement via molecular absorption of carbon monosulfide, CS. • Organic DL

  10. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L−1 HNO3 solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L−1 and 36.4 mg L−1, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93–105% with the repeatability in the range of 4.1–5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg−1), egg white (2188 ± 29 mg kg−1), mineral water (31.0 ± 0.9 mg L−1), white wine (260 ± 4 mg L−1) and red wine (82 ± 2 mg L−1), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L−1). - Highlights: • HR-CS FMAS technique was used for sulfur measurement via molecular absorption of carbon monosulfide, CS. • Organic DL-cysteine in 0.2 mol L−1 HNO3 solution is proposed as a calibration

  11. Determination of nickel in active pharmaceutical ingredients by electrothermal atomic absorption spectrometry.

    Bubnič, Zoran; Urleb, Uroš; Kreft, Katjuša; Veber, Marjan

    2010-03-01

    An electrothermal atomic absorption spectrometric procedure for the determination of nickel in active pharmaceutical ingredients was developed. Since the recoveries of nickel by the direct dissolution of samples in diluted nitric acid were low and caused errors in the determination of Ni in pharmaceutical samples, different approaches for sample pre-treatment were examined. It was found that the microwave digestion was the most suitable way for sample preparation. Various combinations of digestion agents and different microwave conditions were tested. The combination of nitric acid and hydrogen peroxide was found to be the most appropriate. The validity of the method was evaluated by recovery studies of spiked samples and by the comparison of the results obtained by inductively coupled plasma mass spectrometry (ICP-MS). The recovery ranged from 87.5 to 104.0% and a good agreement was achieved between both methods. The detection limit and the limit of quantification were 0.6 and 2.1 µg g-1 respectively. The precision of the method was confirmed by the determination of Ni in the spiked samples and was below 4%, expressed in terms of a relative standard deviation. The method was applied to the determination of nickel in production samples of active pharmaceutical ingredients and intermediates. PMID:24061653

  12. Determination of iron in natural and mineral waters by flame atomic absorption spectrometry

    ROLANDAS KAZLAUSKAS

    2004-05-01

    Full Text Available Simple methods for the determination of Fe in natural and mineral waters by flame atomic absorption spectrometry (AAS are suggested. The results of the investigation of selectivity of the proposed AAS method proved that this procedure is not affected by high concentrations of other metals. The calibration graph for iron was linear at levels near the detection limit up to at least 0.10 mg ml-1. For the determination of microamounts of iron in mineral waters, an extraction AAS technique was developed. Iron was retained as Fe-8-oxyquinoline complex and extracted into chloroform. The optimal conditions for the extraction of the iron complex were determined. The AAS method was applied to the determination of Fe in mineral waters and natural waters from different areas of Lithuania. The accuracy of the developed method was sufficient and evaluated in comparison with a photometric method. The obtained results demonstrated that the procedure could be successfully applied for the analysis of water samples with satisfactory accuracy.

  13. Determination of trace impurities in titanium dioxide by direct solid sampling electrothermal atomic absorption spectrometry

    Vojtková, Blanka; Dočekal, Bohumil

    2005-01-01

    Roč. 99, S (2005), s489-s491. ISSN 0009-2770. [Meeting on Chemistry and Life /3./. Brno, 20.09.2005-22.09.2005] Institutional research plan: CEZ:AV0Z40310501 Keywords : solid sampling * electrothermal atomic absorption spectrometry * trace analysis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.445, year: 2005

  14. Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction

    Saber-Tehrani, Mohammad; Hashemi-Moghaddam, Hamid; Givianrad, Mohammad Hadi; Abroomand-Azar, Parviz [Islamic Azad University, Department of Chemistry, Science and Research Branch, Tehran (Iran)

    2006-11-15

    An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 {mu}g g{sup -1} and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%. (orig.)

  15. Determination of cadmium in real water samples by flame atomic absorption spectrometry after cloud point extraction

    Water pollution is a global threat and it is the leading world wide cause of death and diseases. The awareness of the potential danger posed by heavy metals to the ecosystems and in particular to human health has grown tremendously in the past decades. Separation and preconcentration procedures are considered of great importance in analytical and environmental chemistry. Cloud point is one of the most reliable and sophisticated separation methods for determination of traces quantities of heavy metals. Cloud point methodology was successfully employed for preconcentration of trace quantities of cadmium prior to their determination by flame atomic absorption spectrometry (FAAS). The metals react with 8-hydroxquinoline in a surfactant Triton X-114 medium. The following parameters such as pH, concentration of the reagent and Triton X-114, equilibrating temperature and centrifuging time were evaluated and optimized to enhance the sensitivity and extraction efficiency of the proposed method. Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation and the cadmium content was measured by FAAS. The validation of the procedure was carried out by spiking addition methods. The method was applied for determination of Cd in water samples of different ecosystems (lake and river). (author)

  16. Determination of total selenium in nutritional supplements and selenised yeast by Zeeman-effect graphite furnace atomic absorption spectrometry

    Larsen, Erik Huusfeldt; Ekelund, J.

    1989-01-01

    -effect background corrected graphite furnace atomic absorption spectrometry. A furnace ashing step at 1100 °C was necessary in order to obtain a total recovery of selenium when present in the organic form. Palladium nitrate-magnesium nitrate was used as a matrix modifier. Independent methods were used to determine...

  17. Determination of lead in dolomite by Zeeman electrothermal atomic absorption spectrometry

    The mineral lorandite (TlAsS2), present in the Alshar deposit (Republic of Macedonia), is a possible solar neutrino detector (Freedman et al., 1976). As a result of nuclear reaction between the isotopes of thallium 205Tl and the solar neutrino, 205 Pb is produced. The aim of the idea is to determine the content of Pb in the lorandite, that could give information for the value of solar neutrino flux over extended time (Pavicevic, 1994). A method for the lead determination in dolomite by Zeeman electrothermal atomic absorption spectrometry, is presented. After the dissolution of samples, lead was extracted with sodium diethyldithio-carbamate. The lead-diethyldithiocarbamate complex was extracted into methylisobutyl ketone from a medium of pH 6.0-10.0. The procedure was verified by method of standard additions and by analyzing referent standard samples. A calibration curve (for organic solutions containing up to 1 ng Pb) was made using the proposed extraction procedure for standard solutions of lead. The standard deviation (SD) for 0.5 ng Pb is 0.01 ng and the relative standard deviation ranges from 2.5 to 3.5%. The detection limit of the method, calculated as 3 SD of the blank, was found to be 1.5 ng.g-1. The operation conditions in electrothermal atomic absorption measurements (temperature and time) were: drying - 90oC, 20 s; charring - 400oC, 20 s; atomizing - 1900oC, 3 s; cleaning - 2650oC, 3 s (Author)

  18. Determination of tellurium in indium antimonide semiconductor material by electrothermal atomic absorption spectrometry.

    Shiue, M Y; Sun, Y C; Yang, M H

    2001-08-01

    A method for the determination of the dopant concentration of tellurium in dissolved indium antimonide semiconductor material by electrothermal atomic absorption spectrometry (ETAAS) was developed. Efforts were made to investigate the optimal conditions of the furnace heating program and the effect of palladium modifier on the variation of tellurium and the background absorbance. According to the results obtained, the presence of palladium chemical modifier in the analysis of indium antimonide allowed the successful retention of tellurium in the graphite tube, and the optimum mass of palladium modifier was found to be dependent on the sample matrix concentration. The absorbance profile of tellurium and the background level were significantly improved when a pyrolysis temperature of 1100 degrees C and an atomization temperature of 2200 degrees C were employed in the optimized heating program. With the use of this method, a detection limit of 0.8 microg g(-1) tellurium in indium antimonide could be achieved. The applicability of the proposed method was evaluated by comparison with two independent methods, i.e. slurry sampling-ETAAS and ICP-MS. From the good agreement between the results, it was demonstrated that the proposed method is suitable for the determination of typical dopant concentrations of tellurium in indium antimonide. PMID:11534624

  19. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

    2007-03-15

    The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  20. Stabilizing Agents for Calibration in the Determination of Mercury Using Solid Sampling Electrothermal Atomic Absorption Spectrometry

    Hana Zelinková

    2012-01-01

    Full Text Available Tetramethylene dithiocarbamate (TMDTC, diethyldithiocarbamate (DEDTC, and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS. These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L-1 TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants.

  1. Determination of lead in croatian wines by graphite furnace atomic absorption spectrometry

    A method has been developed for direct determination of lead in wine by graphite furnace atomic absorption spectrometry (GFAAS) with Zeeman-effect background correction. The thermal behaviour of Pb during pyrolysis and atomisation stages was investigated without matrix modifier and in the presence of Pd(NO3)2, Pd(NO3)2 + Mg(NO3)2 x 6H2O, and NH4H2PO4 + Mg(NO3)2 x 6H2O as matrix modifiers. A simple 1:1 dilution of wine samples with Pd(NO3)2 as a matrix modifier proved optimal for accurate determination of Pb in wine. Mean recoveries were 106 % for red and 114 % for white wine, and the detection limit was 3 μg L-1. Within-run precision of measurements for red and white wine was 2.1 % and 1.8 %, respectively. The proposed method was applied for analysis of 23 Croatian wines. Median Pb concentrations were 33 μg L-1, range (16 to 49) μg L-1 in commercially available wines and 46 μg L-1, range (14 to 559) μg L-1 in home-made wines. There were no statistically significant differences (P<0.05) in Pb concentration between commercial and home-made wines or between red and white wines. (authors)

  2. Determination of cadmium in biodiesel using microemulsion and electrothermal atomization atomic absorption spectrometry.

    Lima, Adriana S; Silva, Deise G; Teixeira, Leonardo S G

    2015-01-01

    This work aimed to prepare biodiesel microemulsions for the subsequent quantification of cadmium via graphite furnace atomic absorption spectrometry (GFAAS). The biodiesel samples were prepared using n-propanol as an emulsifier, 10% (v/v) nitric acid as the aqueous phase, and biodiesel. Pseudoternary phase diagrams were constructed to determine the microemulsion region with the specified components. The optimized conditions for microemulsion formation were 57.6% (v/v) n-propanol, 21.2% (v/v) biodiesel, and 21.2% (v/v) nitric acid solution. The stability of the microemulsified system was investigated using aqueous and organic standards, and the system was found to be stable for at least 240 min. The applied pyrolysis and atomization temperatures were 800 and 2000 °C, respectively, and 5 μg of aluminum was used as the chemical modifier. The obtained limits of detection and quantification were 0.2 and 0.5 μg kg(-1), respectively, and the characteristic mass was 1.6 pg. The precision, expressed as the relative standard deviation (% R.S.D., n = 10), was 2.5% for a sample with a cadmium concentration of 6.5 μg kg(-1). The accuracy was determined from addition and recovery experiments, with results varying from 93 to 108% recovery. This study demonstrates that the proposed method based on the use of a microemulsion formation in sample preparation can be applied as an efficient alternative for the determination of cadmium in biodiesel by GFAAS. Cadmium determination in biodiesel samples of different origins (soybean, corn, cotton, and sunflower) was evaluated after acid digestion using the inductively coupled plasma-mass spectrometry (ICP-MS) technique, and the obtained results were compared to the results obtained using the proposed method. The paired t test (95% confidence level) did not show significant differences. The concentrations of cadmium found ranged from 5.3 to 8.0 μg kg(-1). PMID:25381584

  3. Determination of mercury by multisyringe flow injection system with cold-vapor atomic absorption spectrometry

    A new software-controlled time-based multisyringe flow injection system for mercury determination by cold-vapor atomic absorption spectrometry is proposed. Precise known volumes of sample, reducing agent (1.1% SnCl2 in 3% HCl) and carrier (3% HCl) are dispensed into a gas-liquid separation cell with a multisyringe burette coupled with one three-way solenoid valve. An argon flow delivers the reduced mercury to the spectrometer. The optimization of the system was carried out testing reaction coils and gas-liquid separators of different design as well as changing parameters, such as sample and reagents volumes, reagent concentrations and carrier gas flow rate, among others. The analytical curves were obtained within the range 50-5000 ng L-1. The detection limit (3σ b/S) achieved is 5 ng L-1. The relative standard deviation (R.S.D.) was 1.4%, evaluated from 16 successive injections of 250 ng L-1 Hg standard solution. The injection and sample throughput per hour were 44 and 11, respectively. This technique was validated by means of solid and water reference materials with good agreement with the certified values and was successfully applied to fish samples

  4. Organic solvents as interferents in arsenic determination by hydride generation atomic absorption spectrometry with flame atomization

    Karadjova, Irina B.; Lampugnani, Leonardo; Dědina, Jiri; D'Ulivo, Alessandro; Onor, Massimo; Tsalev, Dimiter L.

    2006-05-01

    Interference effects of various organic solvents miscible with water on arsenic determination by hydride generation atomic absorption spectrometry have been studied. Arsine was chemically generated in continuous flow hydride generation system and atomized by using a flame atomizer able to operate in two modes: miniature diffusion flame and flame-in-flame. The effects of experimental variables and atomization mode were investigated: tetrahydroborate and hydrochloric acid concentrations, argon, hydrogen and oxygen supply rates for the microflame, and the distance from the atomization region to the observation zone. The nature of the species formed in the flame due to the pyrolysis of organic solvent vapors entering the flame volume together with arsine is discussed. The observed signal depression in the presence of organic solvents has been mainly attributed to the atomization interference due to heterogeneous gas-solid reaction between the free arsenic atoms and finely dispersed carbon particles formed by carbon radicals recombination. The best tolerance to interferences was obtained by using flame-in-flame atomization (5-10 ml min - 1 of oxygen flow rate), together with higher argon and hydrogen supply rates and elevated observation heights.

  5. Determination of cadmium, cobalt, manganese, copper, nickel, and chromium in concentrated solutions of calcium chloride by electrothermal atomic absorption spectrometry

    A procedure is developed for the direct determination of Cd, Co, Cr, Cu, Mn, and Ni in concentrated solutions of calcium chloride by electrothermal atomic absorption spectrometry. Ascorbic and oxalic acids and magnesium nitrate were examined as chemical modifiers. Oxalic acid was found to be the best modifier. Although an atomic absorption spectrometer with a background correction system of relatively low efficiency (deuterium lamp) was used, elements under study can be reliably determined in the presence of oxalic acid at concentrations of calcium chloride in the solution up to 6%. Because cadmium is evaporated before the major part of the given matrix, it can be determined without modifier

  6. Determination of lithium isotopes at natural abundance levels by atomic absorption spectrometry

    Meier, A.L.

    1982-01-01

    The relationships of the absorption of 6Li and 7Li hollow cathode lamp emissions are used to determine lithium isotopic composition in the natural abundance range of geologic materials. Absorption was found to have a nonlinear dependence upon total lithium concentration and isotopic composition. A method using nonlinear equations to describe the relationship of the absorption of 6Li and 7Li lamp radiation is proposed as a means of calculating isotopic composition that is independent of total lithium concentration.

  7. Determination of Arsenic in Palm Kernel Expeller using Microwave Digestion and Graphite Furnace Atomic Absorption Spectrometry Method

    Abdul Niefaizal Abdul Hammid; Ainie Kuntom; RazaIi Ismail; Norazilah Pardi

    2013-01-01

    A study on the method to determine arsenic in palm kernel expeller wascarried out. Microwave digestion technique is widely applied in the analytical chemistry field. In comparison to conventional sample digestion method, the microwave technique is simple, reduced contamination, usage of safe reagent and matrix completely digested. A graphite furnace atomic absorption spectrometry method was used for the total determination of arsenic in palm kernel expeller. Arsenic was extracted from palm ke...

  8. Determination of attenuation coefficient for self-absorption correction in routine gamma ray spectrometry of environmental bulk sample

    A simple method to determine γ-ray attenuation coefficients using Ba-133 γ-rays was developed and applied to self-absorption correction in routine γ-ray spectrometry for environmental samples composed of unknown matrix elements. Experimental values of the mass attenuation coefficient obtained by the method agree well with calculated values for samples of known elemental composition which was determined by means of chemical analysis. (author)

  9. Determination of Lead in Human Teeth by Hydride Generation Atomic Absorption Spectrometry

    Hassan T. Abdulsahib

    2011-01-01

    Full Text Available Problem statement: The determination of lead in human teeth at concentration levels of ìg/ml is proposed using Hydride Generation Atomic Absorption Spectrometry (HG-AAS. To do this, 2% (wv lanthanum chloride solution is employed as matrix modifying reagent to increase sensitivity and remove matrix interferences. Approach: About 100 µL of sample and 100 µL of 3.0% (m/v NaBH4 are simultaneously injected into carrier streams. The detection of limit of 0.46 µg L-1 for Pb was achieved and the relative standard deviation of 3.0% for 10 µg L-1 lead was obtained. The recovery percentage of the method has been found to be (92.8-100.5% for known quantities of lead added to teeth sample which were completely recovered. A comparison of the proposed method with standard addition method showed nearly results in the same samples of teeth and the results compared with other studies in the world. Results: The method was shown to be satisfactory for determination of traces of lead in teeth samples with excellent accuracy. Teeth analysis reveals that intact teeth contained the highest amounts of lead which provide an evidence that lead may reduce the prevalence of dantal caries. Statistically significant differences (pConclusion: Statistically significant difference between age groups were seen in the mean value of lead concentrations in human teeth, the concentration of lead increased with age. The differences may be due to the exposure of lead and others factors such as differences in diet and drinking water.

  10. Determination of gold in geologic materials by solvent extraction and atomic-absorption spectrometry

    Huffman, Claude; Mensik, J.D.; Riley, L.B.

    1967-01-01

    The two methods presented for the determination of traces of gold in geologic materials are the cyanide atomic-absorption method and the fire-assay atomic-absorption method. In the cyanide method gold is leached with a sodium-cyanide solution. The monovalent gold is then oxidized to the trivalent state and concentrated by extracting into methyl isobutyl ketone prior to estimation by atomic absorption. In the fire-assay atomic-absorption method, the gold-silver bead obtained from fire assay is dissolved in nitric and hydrochloric acids. Gold is then concentrated by extracting into methyl isobutyl ketone prior to determination by atomic absorption. By either method concentrations as low as 50 parts per billion of gold can be determined in a 15-gram sample.

  11. [Determination of Iodine and Iodate in Brine and Seafood Simultaneously by Ultraviolet Absorption Spectrometry].

    Tan, Jun; Zhu, Xia-ping; Liu, Miao-miao; Wei, Zhi-cheng; Sang, Shi-hua

    2015-06-01

    The iodide in samples was oxidized to iodate by bromine water, which could be removed by formic acid, and iodate could be transformed to I3- with excess of I- in phosphoric acid, the iodate in samples could be transformed directly to I3- with excess of I- in phosphoric acid. The I3- solution had strong absorption at 350 and 288 nm, and the absorbance had a linear relationship to the concentration of I3- in a certain range. Total content of iodide and iodate had been detected after samples were oxidized by bromine water and the content of iodate had been detected directly, and the content of iodide was obtained by difference of the two results. Based on this, the method had been established to detect iodide and iodate in brine and seafood simultaneously by ultraviolet absorption spectrometry. The volumes of bromine water, formic acid, phosphoric acid and potassium iodide had been optimized. The effect of illumination, temperature and time also had been discussed. The optional reagents condition for iodide was: 2 drops of 3% bromine water, 0.5 mL of 10% formic acid, 4 mL of 20% phosphoric acid and 1 mL of 100 g x L(-1 KI. The optional reagents condition for iodate was: 0. 2 mL of 20% phosphoric acid and 1 mL of 100 g x L(-1) KI. The absorbance were determined after reacting for 30 min at room temperature and natural light conditions. Under the optimized conditions, the concentration of iodide and iodate in the range of 0 - 1.2 and 0 -1.5 mg x L(-1) were well agreed with Lambert Beer law. The sample blank was detected for twelve times and the detection limit of iodide and iodate were 1.54 and 14.8 μg x L(-1) respectively. The RSD of twelve times determination of 0.8 mg x L(-1) of iodide and iodate were 0.097% and 0.067%, respectively. The iodide and iodate in Zhabuye brine, Hong Feng underground brine, kelp, seaweed and sea cabbage had been detected, the recovery experiments also had been conducted at the same time, the recovery of iodide and iodate were between 80

  12. Direct determination of lead in sweet fruit-flavored powder drinks by electrothermal atomic absorption spectrometry

    Lima, Éder C.; Krug, Francisco José; Arruda, Marco A. Z.

    1998-04-01

    A simplified method for direct determination of lead in sweet fruit-flavored powder drinks, syrups and honeys by electrothermal atomic absorption spectrometry without sample digestion is proposed. Samples were dissolved in water, acidified to 0.2% (v/v) HNO 3, and directly injected into an end-capped transversely heated graphite atomizer (THGA). Building up of carbonaceous residue inside the atomizer was effectively precluded for sugar solutions not exceeding 8.0% (m/v) when a heating program with two pyrolysis steps (600 and 1000°C) was carried out without air-ashing. Under these conditions one atomizer supported about 250 firings. Among various chemical modifiers tested, better recovery and repeatability results were obtained with a 5 μg Pd + 3 μg Mg(NO 3) 2 mixture. Tests carried out with individual concomitants containing up to 1.0 μg Na, K, Ca or Cl, and up to 10.0 μg phosphate or sulphate, and several mixtures of these six concomitants, did not reveal significant interferences on lead atomization. Characteristic mass and detection limit based on integrated absorbance were 15 and 11 pg Pb, respectively. The relative standard deviation based on 10 measurements for typical samples (20-60 ng g -1 Pb) was always lower than 5.5%. The detection limit of 7.0 ng g -1 Pb attained the Codex recommendation for the maximum allowed lead contents in the sugar samples. Application of t-test to the results obtained by the proposed direct analysis, and the official method adopted by Food Chemical Codex, demonstrated that there were no significant differences at the 5% probability level.

  13. Determination of arsenic and cadmium in crude oil by direct sampling graphite furnace atomic absorption spectrometry

    Jesus, Alexandre de; Zmozinski, Ariane Vanessa [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Damin, Isabel Cristina Ferreira [Faculdade Dom Bosco de Porto Alegre, 90520-280, Porto Alegre, RS (Brazil); Silva, Marcia Messias, E-mail: mmsilva@iq.ufrgs.br [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Vale, Maria Goreti Rodrigues [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2012-05-15

    In this work, a direct sampling graphite furnace atomic absorption spectrometry method has been developed for the determination of arsenic and cadmium in crude oil samples. The samples were weighed directly on the solid sampling platforms and introduced into the graphite tube for analysis. The chemical modifier used for both analytes was a mixture of 0.1% Pd + 0.06% Mg + 0.06% Triton X-100. Pyrolysis and atomization curves were obtained for both analytes using standards and samples. Calibration curves with aqueous standards could be used for both analytes. The limits of detection obtained were 5.1 {mu}g kg{sup -1} for arsenic and 0.2 {mu}g kg{sup -1} for cadmium, calculated for the maximum amount of sample that can be analyzed (8 mg and 10 mg) for arsenic and cadmium, respectively. Relative standard deviations lower than 20% were obtained. For validation purposes, a calibration curve was constructed with the SRM 1634c and aqueous standards for arsenic and the results obtained for several crude oil samples were in agreement according to paired t-test. The result obtained for the determination of arsenic in the SRM against aqueous standards was also in agreement with the certificate value. As there is no crude oil or similar reference material available with a certified value for cadmium, a digestion in an open vessel under reflux using a 'cold finger' was adopted for validation purposes. The use of paired t-test showed that the results obtained by direct sampling and digestion were in agreement at a 95% confidence level. Recovery tests were carried out with inorganic and organic standards and the results were between 88% and 109%. The proposed method is simple, fast and reliable, being appropriated for routine analysis. - Highlights: Black-Right-Pointing-Pointer A direct sampling GF AAS method to determine As and Cd in crude oil was proposed. Black-Right-Pointing-Pointer The conventional chemical modifier Pd/Mg has been used to stabilize As and Cd. Black

  14. Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry

    The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs

  15. Dispersive Liquid-Liquid Microextraction of Bismuth in Various Samples and Determination by Flame Atomic Absorption Spectrometry

    Teslima Daşbaşı; Şenol Kartal; Şerife Saçmacı; Ahmet Ülgen

    2016-01-01

    A dispersive liquid-liquid microextraction method for the determination of bismuth in various samples by flame atomic absorption spectrometry is described. In this method, crystal violet was used as counter positive ion for BiCl4 − complex ion, chloroform as extraction solvent, and ethanol as disperser solvent. The analytical parameters that may affect the extraction efficiency like acidity of sample, type and amount of extraction and disperser solvents, amount of ligand, and extraction time ...

  16. Determination of Copper-Based Fungicides by Flame Atomic Absorption Spectrometry Using Digestion Procedure with Sulfuric and Nitric Acid

    Jelena Milinović; Rada Đurović

    2007-01-01

    Copper-based fungicides can be effectively digested by treatment with a mixture of concentrated sulfuric and nitric acid in exactly 15 minutes for the rapid determination via copper using flame atomic absorption spectrometry (AAS). Under optimum conditions, the results of copper fungicide analysis were consistent to those obtained by the AOAC’s recommended method. Recovery values ranged from 98.63 to 103.40%. Relative standard deviation values are lower than 2%. The proposed digestion procedu...

  17. Determination of Trace Silver in Water Samples by Online Column Preconcentration Flame Atomic Absorption Spectrometry Using Termite Digestion Product

    Joyce Nunes Bianchin; Eduardo Carasek; Edmar Martendal

    2011-01-01

    A new method for Ag determination in water samples using solid phase extraction (SPE) coupled to a flow injection system and flame atomic absorption spectrometry was developed. The sorbent used for Ag preconcentration and extraction was the termite digestion product. Flow and chemical variables of the system were optimized through a multivariate procedure. The factors selected were adsorbent mass, buffer type and concentration, sample pH, and sample flow rate. The detection limit and precisio...

  18. Determination of Elements by Atomic Absorption Spectrometry in Medicinal Plants Employed to Alleviate Common Cold Symptoms

    F Zehra Küçükbay; Ebru Kuyumcu

    2014-01-01

    Eleven important medicinal plants generally used by the people of Turkey for the treatment of com-mon cold have been studied for their mineral contents .Eleven minor and major elements (essential ,non-essen-tial and toxic) were identified in the Asplenium adiantum-nigrum L .,Althaea of ficinalis L .,Verbascum phlomoides L .,Euphorbiachamaesyce L .,Zizyphus jujube Miller ,Peganum harmala L .,Arum dioscori-dis Sm .,Sambucus nigra L .,Piper longum L .,Tussilago farfara L .and Elettariacardamomum Maton by employing flame atomic absorption and emission spectrometry and electro-thermal atomic absorption spectrom-etry .Microwave digestion procedure for total concentration was applied under optimized conditions for dissolu-tion of medicinal plants .Plant based biological certified reference materials (CRMs) served as standards for quantification .These elements are found to be present in varying concentrations in the studied plants .The baseline data presented in this work can be used in understanding the role of essential ,non-essential and toxic elements in nutritive ,preventive and therapeutic properties of medicinal plants .

  19. Slurry sampling procedure for the determination of lead in human hair by electrothermal atomic absorption spectrometry

    Complete text of publication follows. Human hair is a stable matrix that presents numerous advantages for human biomonitoring, such as easy collection, low cost, easy transport and storage, information about short- and long-term exposure (Angerer J et al., Int. J. Hyg. Environ. Health, 2007, 201-228). The use of the slurry sampling procedure was applied for the determination of lead in human hair by electrothermal atomic absorption spectrometry (ETAAS). This technique presents high sensitivity, low cost and the possibility of direct determination. Hair samples were pulverized using a cryogenic mill. Ten milligrams of the hair powder were transferred into a polyethylene vial and 2 ml of 2.5% HNO3 and 1.5% H2O2 were added. The slurries were maintained homogeneous with air bubbling with an aquarium pump. Niobium and Rhodium were chosen from several potential permanent modifiers by evaluating the background and absorbance signals obtained under the conditions recommended by the manufacturer. A 23 factorial design and a central composite design (CCD) were realized to optimize permanent modifier and pyrolysis and atomization temperatures. The parameters of merit were obtained in the optimized conditions (Tp = 660 deg C, Ta = 1780 deg C and Rh), and they were as follows: linear working range up to 50 μg L-1; limit of detection (0.032 0.002) μg g-1; limit of quantification (0.106 0.005) μg g-1; matrix-matched calibration, with r2 > 0.99 and reproducibility ranged from 2.3 to 4.2 relative standard deviation (RSD). The accuracy was evaluated by recovery tests and comparing slurry sampling and microwave decomposition. The recovery values for different concentrations were in the range between 89 and 101% and non-significant differences were observed (t-test; p = 0.05) when comparing the average of lead values obtained from microwave decomposition method and proposed method. Lead concentrations in different samples ranged between 0.13 and 1.11 μg g-1. The authors kindly

  20. Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

    Freschi, Gian P. G.; Dakuzaku, Carolina S.; de Moraes, Mercedes; Nóbrega, Joaquim A.; Gomes Neto, José A.

    2001-10-01

    A method has been developed for the direct simultaneous determination of Cd and Pb in white and red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of both analytes during pyrolysis and atomization stages were investigated in 0.028 mol l -1 HNO 3 and in 1+1 v/v diluted wine using mixtures of Pd(NO 3) 2+Mg(NO 3) 2 and NH 4H 2PO 4+Mg(NO 3) 2 as chemical modifiers. With 5 μg Pd+3 μg Mg as the modifiers and a two-step pyrolysis (10 s at 400°C and 10 s at 600°C), the formation of carbonaceous residues inside the atomizer was avoided. For 20 μl of sample (wine+0.056 mol l -1 HNO 3, 1+1, v/v) dispensed into the graphite tube, analytical curves in the 0.10-1.0 μg l -1 Cd and 5.0-50 μg l -1 Pb ranges were established. The characteristic mass was approximately 0.6 pg for Cd and 33 pg for Pb, and the lifetime of the tube was approximately 400 firings. The limits of detection (LOD) based on integrated absorbance (0.03 μg l -1 for Cd, 0.8 μg l -1 for Pb) exceeded the requirements of Brazilian Food Regulations (decree #55871 from Health Department), which establish the maximum permissible level for Cd at 200 μg l -1 and for Pb at 500 μg l -1. The relative standard deviations ( n=12) were typically <8% for Cd and <6% for Pb. The recoveries of Cd and Pb added to wine samples varied from 88 to 107% and 93 to 103%, respectively. The accuracy of the direct determination of Cd and Pb was checked for 10 table wines by comparing the results with those obtained for digested wine using single-element ET-AAS, which were in agreement at the 95% confidence level.

  1. Exploiting flow injection and sequential injection for trace metal determinations in conjunction with detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    Hansen, Elo Harald

    Despite their excellent analytical chemical capacities, Electrothermal Atomic Absorption Spectrometry (ETAAS) and Inductively Coupled Plasma Mass Spectrometry (ICPMS), nevertheless, often require suitable pretreatment of the sample material in order to obtain the necessary sensitivity and...

  2. Fluorine determination in coal using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    The absorption of the calcium mono-fluoride (CaF) molecule has been employed in this study for the determination of fluorine in coal using direct solid sample analysis and high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). The rotational line at 606.440 nm was used for measuring the molecular absorption in the gas phase. The pyrolysis and vaporization temperatures were 700 °C and 2100 °C, respectively. Different chemical modifiers have been studied, such as Pd and Ir as permanent modifiers, and Pd and the mixed Pd/Mg modifier in solution. The limit of detection and the characteristic mass were 0.3 and 0.1 ng F, respectively. One certified reference material (CRM) of coal (NIST 1635) and four CRMs with a non-certified value for F (SARM 18, SARM 20, BCR 40, BCR 180) were used to evaluate the accuracy and precision of the method, obtaining good agreement (104%) with the certified value and with the informed values (ranging from 90 to 103%). - Highlights: • High-resolution Graphite Furnace Molecular Absorption Spectrometry (HR-GF MAS) • Fluorine has been determined using HR-GF MAS of the CaF molecule. • The CaF molecule was generated in a graphite furnace at a temperature of 2100 °C • Coal samples have been analyzed using direct solid sample introduction. • Aqueous standard solutions have been used for calibration

  3. Fluorine determination in coal using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Machado, Patrícia M.; Morés, Silvane; Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Welz, Bernhard, E-mail: w.bernardo@terra.com.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Carasek, Eduardo [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2015-03-01

    The absorption of the calcium mono-fluoride (CaF) molecule has been employed in this study for the determination of fluorine in coal using direct solid sample analysis and high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). The rotational line at 606.440 nm was used for measuring the molecular absorption in the gas phase. The pyrolysis and vaporization temperatures were 700 °C and 2100 °C, respectively. Different chemical modifiers have been studied, such as Pd and Ir as permanent modifiers, and Pd and the mixed Pd/Mg modifier in solution. The limit of detection and the characteristic mass were 0.3 and 0.1 ng F, respectively. One certified reference material (CRM) of coal (NIST 1635) and four CRMs with a non-certified value for F (SARM 18, SARM 20, BCR 40, BCR 180) were used to evaluate the accuracy and precision of the method, obtaining good agreement (104%) with the certified value and with the informed values (ranging from 90 to 103%). - Highlights: • High-resolution Graphite Furnace Molecular Absorption Spectrometry (HR-GF MAS) • Fluorine has been determined using HR-GF MAS of the CaF molecule. • The CaF molecule was generated in a graphite furnace at a temperature of 2100 °C • Coal samples have been analyzed using direct solid sample introduction. • Aqueous standard solutions have been used for calibration.

  4. Direct determination of selenium in rat blood plasma by Zeeman atomic absorption spectrometry.

    Kabirov, K K; Kapetanovic, I M; Lyubimov, A V

    2008-01-30

    The method was developed to be applied for direct determination of selenium in rat plasma by graphite-furnace atomic absorption spectrometry with Zeeman background correction. Blood was obtained from CD rats of both sexes 2h after dosing in weeks 7 and 13 in order to acquire data on the levels of selenium in these animals during 13-week gavage administration of l-seleno-methylselenocysteine (SeMC), a new candidate chemopreventive agent under development. Application of the commonly used method of standard addition was found to be unsuitable to calculate the selenium content in rat plasma (within-run and between-run accuracy and precision parameters were less than 85%). Therefore, a new analytical method was developed. In this method, samples of rat plasma (50 microL) were diluted 10-fold with a reducing agent containing l-ascorbic acid, a modifier solution containing palladium chloride and Triton X-100. Samples were atomized in pyrolytically coated graphite tubes and peak height signals were measured. Selenium concentrations were determined by linear least squares regression analysis based on the standard curve generated in pooled rat blank plasma. Since selenium is normally present in plasma, a three-step approach was used to calculate selenium plasma levels. Initially selenium levels were determined based on the standard curve with selenium-spiked pool plasma. In the second step, background selenium levels in the pooled plasma were determined based on the same standard curve. In the third step, background level was added to the previously derived number. The relative errors were in the range from -4.6 to 11.4% (intra-day assay) and from -0.4 to 8.8% (inter-day assay) which proved good accuracy. The relative standard deviations were in the range from 1.88 to 4.70% (intra-day precision) and from 3.28 to 5.38% (inter-day precision). In rat plasma, the following dose-dependent selenium levels (mean+/-S.D.) in males and females, respectively, were observed at 13 weeks

  5. Optimization of conditions for the determination of Eu, Gd and Sm by atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES)

    The possibilities of the determination of Sm, Eu and Gd by atomic absorption and emission spectrometry were investigated. Measurement parameters on a Varian atomic absorption spectrometer were optimized (the height of the measurement above the nozzle of the burner, stoichiometry of the dinitrogen oxide-acetylene flame by statistical evaluation of the signals). The following optimal conditions were found for the Sm, Eu and Gd determinations: Samarium - measurement under the emission arrangement at 476.1 nm wavelength, slit width 0.05 nm, in reduction flame close to the outlet slit of the flame (at the lowest part of the flame). Europium - measurement under the absorption arrangement at 459.4 nm wavelength, slit width 1 nm, in reduction flame at the lowest part of the flame. Gadolinium - measurement under the emission arrangement at 461.7 nm wavelength, slit width 0.05 nm, at the lowest part of the flame. (author). 2 figs., 3 tabs., 2 refs

  6. Determination of Heavy Metals in Meat, Intestine, Liver, Eggs, and Chicken Using Neutron Activation Analysis and Atomic Absorption Spectrometry

    The elements As, Cd, Co, Cr, Fe, Hg, Ni, Pb, Sb, se and Zn in meat, intestine, and liver of cow and goat, as well as in broiler, local breed chicken and eggs have been determined using Neutron Activation Analysis and Atomic Absorption Spectrometry. Mercury was determined after being separated radiochemically. The results showed that concentration of the essential elements studied i.e. Cr, Cu, Fe, Zn, Co, and Ni were higher in liver and intestine than in the meat, but still in the normal range, while toxic elements As, Cd, and Pb were undetectable in all samples. (author). 8 refs., 6 tabs

  7. Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

    Sardans, Jordi, E-mail: j.sardans@creaf.uab.ca [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain); Montes, Fernando [Departamento de Ciencias Analiticas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/ Senda del Rey 9. 28040 Madrid (Spain); Penuelas, Josep [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain)

    2010-02-15

    Pollution from heavy metals has increased in recent decades and has become an important concern for environmental agencies. Arsenic, cadmium, copper, mercury and lead are among the trace elements that have the greatest impact and carry the highest risk to human health. Electrothermal atomic absorption spectrometry (ETAAS) has long been used for trace element analyses and over the past few years, the main constraints of atomic absorption spectrometry (AAS) methods, namely matrix interferences that provoked high background absorption and interferences, have been reduced. The use of new, more efficient modifiers and in situ trapping methods for stabilization and pre-concentration of these analytes, progress in control of atomization temperatures, new designs of atomizers and advances in methods to correct background spectral interferences have permitted an improvement in sensitivity, an increase in detection power, reduction in sample manipulation, and increase in the reproducibility of the results. These advances have enhanced the utility of Electrothermal atomic absorption spectrometry (ETAAS) for trace element determination at mug L{sup -1} levels, especially in difficult matrices, giving rise to greater reproducibility, lower economic cost and ease of sample pre-treatment compared to other methods. Moreover, the recent introduction of high resolution continuum source Electrothermal atomic absorption spectrometry (HR-CS-ETAAS) has facilitated direct solid sampling, reducing background noise and opening the possibility of achieving even more rapid quantitation of some elements. The incorporation of flow injection analysis (FIA) systems for automation of sample pre-treatment, as well as chemical vapor generation renders (ETAAS) into a feasible option for detection of As and Hg in environmental and food control studies wherein large numbers of samples can be rapidly analyzed. A relatively inexpensive approach with low sample consumption provide additional advantages

  8. Determination of self-absorption corrections by computation in routine gamma-ray spectrometry for typical environmental samples

    A simple and practical method has been developed to quickly calculate self-absorption corrections and mass attenuation coefficients, μ/p, in common environmental samples being analyzed by gamma-ray spectrometry. The method involves using a sample computer program and estimates of the elemental compositions of typical environmental samples. The use of this method eliminates the need for gamma-ray-transmission measurements of individual samples, as well as expensive and time consuming elemental analyses of routine samples. The calculated percent attenuation of the beam through various samples, as determined by this method, agrees very well with experimentally measured values of percent attenuation

  9. Air quality status in Kinshasa as determined by instrumental neutron activation analysis, atomic absorption spectrometry and ion-exchange chromatography

    Three independent analytical techniques - instrumental neutron activation analysis. Atomic absorption spectrometry and ion-exchange chromatography - were applied to airborne particulate collected on filters and to atmospheric acid gases collected in carbonate buffer solutions. 20 trace elements and 7 acid gases and acid aerosols were determined. Results were compared with those observed elsewhere and showed that air pollution is low in Kinshasa and does not give rise to anxieties. The main known sources of pollutants are: vehicle exhaust and aeolian process on stripped soils. (author). 13 refs, 2 figs, 6 tabs

  10. Cadmium, copper, lead, and zinc determination in precipitation: A comparison of inductively coupled plasma atomic emission spectrometry and graphite furnace atomization atomic absorption spectrometry

    Reddy, M.M.; Benefiel, M.A.; Claassen, H.C.

    1987-01-01

    Selected trace element analysis for cadmium, copper, lead, and zinc in precipitation samples by inductively coupled plasma atomic emission Spectrometry (ICP) and by atomic absorption spectrometry with graphite furnace atomization (AAGF) have been evaluated. This task was conducted in conjunction with a longterm study of precipitation chemistry at high altitude sites located in remote areas of the southwestern United States. Coefficients of variation and recovery values were determined for a standard reference water sample for all metals examined for both techniques. At concentration levels less than 10 micrograms per liter AAGF analyses exhibited better precision and accuracy than ICP. Both methods appear to offer the potential for cost-effective analysis of trace metal ions in precipitation. ?? 1987 Springer-Verlag.

  11. Zeeman atomic absorption spectrometry

    The design and development of a Zeeman atomic absorption spectrometer for trace element analysis are described. An instruction manual is included which details the operation, adjustment, and maintenance. Specifications and circuit diagrams are given

  12. Determination of total selenium in pharmaceutical and herbal supplements by hydride generation and graphite furnace atomic absorption spectrometry.

    Kazi, Tasneem G; Kolachi, Nida F; Afridi, Hassan I; Brahman, Kapil Dev; Shah, Faheem

    2014-01-01

    The total selenium (Se) was determined in herbal and pharmaceutical supplements used for liver diseases. The total Se contents were determined in different pharmaceutical and herbal supplements by hydride generation atomic absorption spectrometry (HGAAS) and graphite furnace atomic absorption spectrometry (GFAAS) after microwave-assisted acid digestion. The accuracy of the techniques was evaluated by using certified reference material and the standard addition method. The recoveries of total Se were 99.4 and 99.0% for HGAAS and GFAAS, respectively. The precision of the techniques expressed as RSD were 2.34 and 4.54% for HGAAS and GFAAS measurements, respectively. The LOD values for HGAAS and GFAAS were 0.025 and 0.052 pglg, respectively. The concentrations of Se in pharmaceutical and herbal supplements were found in the range of 19.2-53.8 and 25.0-42.5 pg/g, respectively, corresponding to 35-76% and 45-76% of the total recommended dose of Se for adults. PMID:25632445

  13. Application of multiwalled carbon nanotubes treated by potassium permanganate for determination of trace cadmium prior to flame atomic absorption spectrometry

    2007-01-01

    In this study we investigated the enrichment ability of oxidized multiwalled carbon nanotubes (MWCNTs) and established a new method for the determination of trace cadmium in environment with flame atomic absorption spectrometry. The MWCNTs were oxidized by potassium permanganate under appropriate conditions before use as preconcentration packing. Parameters influencing the recoveries of target analytes were optimized. Under optimal conditions, the target analyte exhibited a good linearity (R2=0.9992)over the concentration range 0.5-50 ng/ml. The detection limit and precision of the proposed method were 0.15 ng/ml and 2.06%,respectively. The proposed method was applied to the determination of cadmium in real-world environmental samples and the recoveries were in the range of 91.3%-108.0%. All these experimental results indicated that this new procedure could be applied to the determination of trace cadmium in environmental waters.

  14. Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

    Elsheimer, H.N.; Fries, T.L.

    1990-01-01

    A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of tricotylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 ??g l-1 of tin in the MIBK solution or 0.2-0.3 ??g g-61 in the rock. The concentration range is linear between 2.5 and 500 ??g l-1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 ??g l-1 level and < 7% at the 10-30 ??g l-1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 ??g g-1 or less.

  15. A highly sensitive method for the determination of mercury using vapor generation gold wire microextraction and electrothermal atomic absorption spectrometry

    The study introduces a new simple and highly sensitive method for headspace solid phase microextraction (HS-SPME) coupled with electrothermal atomic absorption spectrometric determination of mercury. In the proposed method, a gold wire, mounted in the headspace of a sample solution in a sealed bottle, is used for collection of mercury vapor generated by addition of sodium tetrahydroborate. The gold wire is then simply inserted in the sample introduction hole of a graphite furnace of an electrothermal atomic absorption spectrometry instrument. By applying an atomization temperature of 600 deg. C, mercury is rapidly desorbed from the wire and determined with high sensitivity. Factorial design and response surface analysis methods were used for optimization of the effect of five different variables in order to maximize the mercury signal. By using a 0.75 mm diameter gold wire, a sample volume of about 8 ml and an extraction time of 11 min, the sensitivity of mercury determination was enhanced up to 104 times in comparison to its ordinary ETAAS determination with direct injection of 10 μl sample solutions. A detection limit of 0.006 ng ml-1 and a precision better than 4.6% (relative standard deviation) were obtained. The method was successfully applied to the determination of mercury in industrial wastewaters and tuna fish samples

  16. A highly sensitive method for the determination of mercury using vapor generation gold wire microextraction and electrothermal atomic absorption spectrometry

    Hashemi, Payman [Department of Chemistry, Lorestan University, Khorram Abad (Iran, Islamic Republic of)], E-mail: payman_hashemi@yahoo.com; Rahimi, Akram [Department of Chemistry, Lorestan University, Khorram Abad (Iran, Islamic Republic of)

    2007-04-15

    The study introduces a new simple and highly sensitive method for headspace solid phase microextraction (HS-SPME) coupled with electrothermal atomic absorption spectrometric determination of mercury. In the proposed method, a gold wire, mounted in the headspace of a sample solution in a sealed bottle, is used for collection of mercury vapor generated by addition of sodium tetrahydroborate. The gold wire is then simply inserted in the sample introduction hole of a graphite furnace of an electrothermal atomic absorption spectrometry instrument. By applying an atomization temperature of 600 deg. C, mercury is rapidly desorbed from the wire and determined with high sensitivity. Factorial design and response surface analysis methods were used for optimization of the effect of five different variables in order to maximize the mercury signal. By using a 0.75 mm diameter gold wire, a sample volume of about 8 ml and an extraction time of 11 min, the sensitivity of mercury determination was enhanced up to 10{sup 4} times in comparison to its ordinary ETAAS determination with direct injection of 10 {mu}l sample solutions. A detection limit of 0.006 ng ml{sup -1} and a precision better than 4.6% (relative standard deviation) were obtained. The method was successfully applied to the determination of mercury in industrial wastewaters and tuna fish samples.

  17. Ultrasensitive determination of cadmium in seawater by hollow fiber supported liquid membrane extraction coupled with graphite furnace atomic absorption spectrometry

    Peng, Jin-feng; Liu, Rui; Liu, Jing-fu; He, Bin; Hu, Xia-lin; Jiang, Gui-bin

    2007-05-01

    A new procedure, based on hollow fiber supported liquid membrane preconcentration coupled with graphite furnace atomic absorption spectrometry (GFAAS) detection, was developed for the determination of trace Cd in seawater samples. With 1-octanol that contained a mixture of dithizone (carrier) and oleic acid immobilized in the pores of the polypropylene hollow fiber as a liquid membrane, Cd was selectively extracted from water samples into 0.05 M HNO 3 that filled the lumen of the hollow fiber as a stripping solution. The main extraction related parameters were optimized, and the effects of salinity and some coexisting interferants were also evaluated. Under the optimum extraction conditions, an enrichment factor of 387 was obtained for a 100-mL sample solution. In combination with graphite furnace atomic absorption spectrometry, a very low detection limit (0.8 ng L - 1 ) and a relative standard deviation (2.5% at 50 ng L - 1 level) were achieved. Five seawater samples were analyzed by the proposed method without dilution, with detected Cd concentration in the range of 56.4-264.8 ng L - 1 and the relative spiked recoveries over 89%. For comparison, these samples were also analyzed by the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method after a 10-fold dilution for matrix effect elimination. Statistical analysis with a one-way ANOVA shows no significant differences (at 0.05 level) between the results obtained by the proposed and ICP-MS methods. Additionally, analysis of certified reference materials (GBW (E) 080040) shows good agreement with the certified value. These results indicate that this present method is very sensitive and reliable, and can effectively eliminate complex matrix interferences in seawater samples.

  18. Ultrasensitive determination of cadmium in seawater by hollow fiber supported liquid membrane extraction coupled with graphite furnace atomic absorption spectrometry

    Peng Jinfeng; Liu Rui [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085 (China); Liu Jingfu [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085 (China)], E-mail: jfliu@rcees.ac.cn; He Bin; Hu Xialin; Jiang Guibin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P. O. Box 2871, Beijing 100085 (China)

    2007-05-15

    A new procedure, based on hollow fiber supported liquid membrane preconcentration coupled with graphite furnace atomic absorption spectrometry (GFAAS) detection, was developed for the determination of trace Cd in seawater samples. With 1-octanol that contained a mixture of dithizone (carrier) and oleic acid immobilized in the pores of the polypropylene hollow fiber as a liquid membrane, Cd was selectively extracted from water samples into 0.05 M HNO{sub 3} that filled the lumen of the hollow fiber as a stripping solution. The main extraction related parameters were optimized, and the effects of salinity and some coexisting interferants were also evaluated. Under the optimum extraction conditions, an enrichment factor of 387 was obtained for a 100-mL sample solution. In combination with graphite furnace atomic absorption spectrometry, a very low detection limit (0.8 ng L{sup -1}) and a relative standard deviation (2.5% at 50 ng L{sup -1} level) were achieved. Five seawater samples were analyzed by the proposed method without dilution, with detected Cd concentration in the range of 56.4-264.8 ng L{sup -1} and the relative spiked recoveries over 89%. For comparison, these samples were also analyzed by the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method after a 10-fold dilution for matrix effect elimination. Statistical analysis with a one-way ANOVA shows no significant differences (at 0.05 level) between the results obtained by the proposed and ICP-MS methods. Additionally, analysis of certified reference materials (GBW (E) 080040) shows good agreement with the certified value. These results indicate that this present method is very sensitive and reliable, and can effectively eliminate complex matrix interferences in seawater samples.

  19. Ultrasensitive determination of cadmium in seawater by hollow fiber supported liquid membrane extraction coupled with graphite furnace atomic absorption spectrometry

    A new procedure, based on hollow fiber supported liquid membrane preconcentration coupled with graphite furnace atomic absorption spectrometry (GFAAS) detection, was developed for the determination of trace Cd in seawater samples. With 1-octanol that contained a mixture of dithizone (carrier) and oleic acid immobilized in the pores of the polypropylene hollow fiber as a liquid membrane, Cd was selectively extracted from water samples into 0.05 M HNO3 that filled the lumen of the hollow fiber as a stripping solution. The main extraction related parameters were optimized, and the effects of salinity and some coexisting interferants were also evaluated. Under the optimum extraction conditions, an enrichment factor of 387 was obtained for a 100-mL sample solution. In combination with graphite furnace atomic absorption spectrometry, a very low detection limit (0.8 ng L-1) and a relative standard deviation (2.5% at 50 ng L-1 level) were achieved. Five seawater samples were analyzed by the proposed method without dilution, with detected Cd concentration in the range of 56.4-264.8 ng L-1 and the relative spiked recoveries over 89%. For comparison, these samples were also analyzed by the Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method after a 10-fold dilution for matrix effect elimination. Statistical analysis with a one-way ANOVA shows no significant differences (at 0.05 level) between the results obtained by the proposed and ICP-MS methods. Additionally, analysis of certified reference materials (GBW (E) 080040) shows good agreement with the certified value. These results indicate that this present method is very sensitive and reliable, and can effectively eliminate complex matrix interferences in seawater samples

  20. Evaluation of quartz tubes as atomization cells for gold determination by thermospray flame furnace atomic absorption spectrometry

    This work describes the development of a new analytical procedure able to determine gold by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) using nickel tubes (NiT) and quartz tubes (QT) as atomization cells. Experiments involving changes in the flow injection operational parameters, reagent concentrations and sizes of the QT were performed in order to optimize sensitivity. Under the same operational conditions, it was observed that the employment of QT increases the sensitivity of gold determination when compared to the nickel tube. Since solutions of highly concentrated hydrochloric acid showed the best performance as carriers, quartz tubes were also preferred due to its greater tolerance to corrosion by mineral acids in comparison to NiT. In addition, changes in the internal diameter of the QT revealed an important improvement in sensitivity for smaller tubes. Under optimized conditions the main figures of merit showed values close to that of graphite furnace atomic absorption spectrometry with the addition of an excellent improvement of the sample throughput. They are: LOD (3 s): 0.004 μg mL−1, sensitivity: 0.306 (μg mL−1)−1, RSD% (n = 10, 1 μg mL−1): 2.5, linear range: 0.01–4 μg mL−1 and sample throughput: 72 h−1. This new method was employed for the determination of gold in homeopathic medicines with no need of sample digestion. Validation of the analytical results will be shown. A full discussion of the most relevant findings regarding the role of the atomization cell as a strategic key for improving sensitivity will be also provided. - Highlights: ► Quartz tubes as furnaces in TS-FFAAS. ► Small tubes for controlling radial dispersion. ► Improved figures of merit for gold determination. ► Analysis of homeopathic medicines.

  1. Fluorine determination in coal using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Machado, Patrícia M.; Morés, Silvane; Pereira, Éderson R.; Welz, Bernhard; Carasek, Eduardo; de Andrade, Jailson B.

    2015-03-01

    The absorption of the calcium mono-fluoride (CaF) molecule has been employed in this study for the determination of fluorine in coal using direct solid sample analysis and high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS). The rotational line at 606.440 nm was used for measuring the molecular absorption in the gas phase. The pyrolysis and vaporization temperatures were 700 °C and 2100 °C, respectively. Different chemical modifiers have been studied, such as Pd and Ir as permanent modifiers, and Pd and the mixed Pd/Mg modifier in solution. The limit of detection and the characteristic mass were 0.3 and 0.1 ng F, respectively. One certified reference material (CRM) of coal (NIST 1635) and four CRMs with a non-certified value for F (SARM 18, SARM 20, BCR 40, BCR 180) were used to evaluate the accuracy and precision of the method, obtaining good agreement (104%) with the certified value and with the informed values (ranging from 90 to 103%).

  2. Column system using diaion HP-2MG for determination of some metal ions by flame atomic absorption spectrometry

    Tuzen, Mustafa; Soylak, Mustafa

    2004-02-23

    A column solid-phase extraction method for the preconcentration and determination of cadmium(II), copper(II), cobalt(II), iron(III), lead(II), nickel(II) and zinc(II) dithizone chelates by atomic absorption spectrometry has been described. Diaion HP-2MG was used as adsorbent for column studies. The influences of the various analytical parameters including pH of the aqueous solutions, amounts of ligand and resin were investigated for the retentions of the analyte ions. The recovery values are ranged from 95 to 102%. The influences of alkaline and earth alkaline ions were also discussed. The preconcentration factor was 375, when the sample volume and final volume are 750 and 2 ml, respectively. The detection limits of the analyte ions (k=3, N=21) were varying 0.08 {mu}g/l for cadmium to 0.25 {mu}g/l for lead. The relative standard deviations of the determinations at the concentration range of 1.8x10{sup -4} to 4.5x10{sup -5} mmol for the investigated elements were found to be lower than 9%. The proposed solid-phase extraction procedure were applied to the flame atomic absorption spectrometric determinations of analyte ions in natural waters (sea, tap, river), microwave digested samples (milk, red wine and rice) and two different reference standard materials (SRM1515 apple leaves and NRCC-SLRS-4 riverine water)

  3. The determination of caesium and silver in soil and fungal fruiting bodies by electrothermal atomic absorption spectrometry

    Methods have been developed for the determination of caesium and silver in soil and fungal samples by microwave-assisted aqua regia digestion, followed by electrothermal atomic absorption spectrometry. The procedure was found to be repeatable (for soil, RSD -1, respectively, and for fungi, RSD -1, respectively) and reasonably efficient. Silver was recovered quantitatively from reference soils, but only about 80-85% of the caesium present could be extracted. Poorer caesium recoveries (< 70%) were obtained if, as part of the sample preparation procedure, solutions were taken to dryness in glass beakers prior to analysis. The detection limits were 0.02 mg Ag and 0.09 mg Cs per gram of dry soil, which are adequate for the determination of the analytes at typical environmental levels. The methods were applied in the analysis of three types of soil, a peaty podzol, a clay loam and a sandy loam and no significant matrix interferences were observed except in the determination of caesium in the sandy loam. For caesium, non-linear response curves, thought to be due to ionisation interference, were encountered using one atomic absorption spectrometer, but were not observed with the other instrument

  4. Matrix elimination method for the determination of precious metals in ores using electrothermal atomic absorption spectrometry.

    Salih, Bekir; Celikbiçak, Omür; Döker, Serhat; Doğan, Mehmet

    2007-03-28

    Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using (60)Co gamma source in the ternary mixture of NHMMA-ATU-H(2)O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L(-1) of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels. PMID:17386783

  5. Matrix elimination method for the determination of precious metals in ores using electrothermal atomic absorption spectrometry

    Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using 60Co γ source in the ternary mixture of NHMMA-ATU-H2O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3 M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L-1 of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels

  6. Determination of Chlorine in Milk via Molecular Absorption of SrCl Using High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry.

    Ozbek, Nil; Akman, Suleyman

    2016-07-20

    Total chlorine in milk was determined via the molecular absorption of diatomic strontium monochloride at 635.862 nm using high-resolution continuum source graphite furnace atomic absorption spectrometry. The effects of coating the graphite furnace, using different modifiers, amount of molecule-forming element, and different calibrants were investigated and optimized. Chlorine concentrations in milk samples were determined in a Zr-coated graphite furnace using 25 μg of Sr as the molecule-forming reagent and applying a pyrolysis temperature of 600 °C and a molecule-forming temperature of 2300 °C. Linearity was maintained up to 500 μg mL(-1) of Cl. The method was tested by analyzing a certified reference wastewater. The results were in the uncertainty limits of the certified value. The limit of detection of the method was 1.76 μg mL(-1). The chlorine concentrations in various cow milk samples taken from the market were found in the range of 588-1472 mg L(-1). PMID:27345208

  7. Determination of Nickel in Water and Wastewater at Ultratrace Level by Solid-Phase Extraction-Flame Atomic Absorption Spectrometry

    Solid-phase extraction using octadecyl silica membrane disk modified with 2[(2-mercaptophenylimino)methyl] phenol (MPMP) ligand was utilized in FAAS determination of ultratrace amount of nickel in water and wastewater samples. Ni2+ ions were adsorbed quantitatively during the passage of an aqueous sample through the modified octadecyl silica membrane disk. The retained Ni2+ ions were then eluted from the disk with 5 mL of 0.5 mol L-1 nitric acid as an eluent, and subsequently determined by FAAS. The break-through volume of the method was 2000 mL, which corresponded to the enrichment factor of 400. Maximum capacity of the membrane disk modified with 6 mg of the ligand was 210 μg of Ni2+, and the limit of determination was 0.17 μg L-1. The effect of various ionic interferences on preconcentration and determination of nickel in binary mixture was studied. The method was successfully applied to determination of nickel in water and wastewater samples; accuracy was examined in recovery experiment and by independent GFAAS analysis (graphite furnace atomic absorption spectrometry). The accuracy was further confirmed by applying the proposed method to the analysis of standard reference alloy (BCR No 112) and comparing the result with the declared value. (authors)

  8. Direct determination of cadmium in Orujo spirit samples by electrothermal atomic absorption spectrometry: Comparative study of different chemical modifiers

    Vilar Farinas, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Barciela Garcia, J. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Garcia Martin, S. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Pena Crecente, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Herrero Latorre, C. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain)]. E-mail: cherrero@lugo.usc.es

    2007-05-22

    In this work, several analytical methods are proposed for cadmium determination in Orujo spirit samples using electrothermal atomic absorption spectrometry (ETAAS). Permanent chemical modifiers thermally coated on the platforms inserted in pyrolytic graphite tubes (such as W, Ir, Ru, W-Ir and W-Ru) were comparatively studied in relation to common chemical modifier mixtures [Pd-Mg(NO{sub 3}){sub 2} and (NH{sub 4})H{sub 2}PO{sub 4}-Mg(NO{sub 3}){sub 2}] for cadmium stabilization. Different ETAAS Cd determination methods based on the indicated modifiers have been developed. In each case, pyrolysis and atomization temperatures, atomization shapes, characteristic masses and detection limits as well as other analytical characteristics have been determined. All the assayed modifiers (permanent and conventional) were capable of achieving the appropriate stabilization of the analyte, with the exception of Ru and W-Ru. Moreover, for all developed methods, recoveries (99-102%) and precision (R.S.D. lower than 10%) were acceptable. Taking into account the analytical performance (best detection limit LOD = 0.01 {mu}g L{sup -1}), the ETAAS method based on the use of W as a permanent modifier was selected for further direct Cd determinations in Orujo samples from Galicia (NW Spain). The chosen method was applied in the determination of the Cd content in 38 representative Galician samples. The cadmium concentrations ranged

  9. Direct determination of cadmium in Orujo spirit samples by electrothermal atomic absorption spectrometry: Comparative study of different chemical modifiers

    In this work, several analytical methods are proposed for cadmium determination in Orujo spirit samples using electrothermal atomic absorption spectrometry (ETAAS). Permanent chemical modifiers thermally coated on the platforms inserted in pyrolytic graphite tubes (such as W, Ir, Ru, W-Ir and W-Ru) were comparatively studied in relation to common chemical modifier mixtures [Pd-Mg(NO3)2 and (NH4)H2PO4-Mg(NO3)2] for cadmium stabilization. Different ETAAS Cd determination methods based on the indicated modifiers have been developed. In each case, pyrolysis and atomization temperatures, atomization shapes, characteristic masses and detection limits as well as other analytical characteristics have been determined. All the assayed modifiers (permanent and conventional) were capable of achieving the appropriate stabilization of the analyte, with the exception of Ru and W-Ru. Moreover, for all developed methods, recoveries (99-102%) and precision (R.S.D. lower than 10%) were acceptable. Taking into account the analytical performance (best detection limit LOD = 0.01 μg L-1), the ETAAS method based on the use of W as a permanent modifier was selected for further direct Cd determinations in Orujo samples from Galicia (NW Spain). The chosen method was applied in the determination of the Cd content in 38 representative Galician samples. The cadmium concentrations ranged -1

  10. Method development for the determination of manganese, cobalt and copper in green coffee comparing direct solid sampling electrothermal atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry.

    Oleszczuk, Nédio; Castro, Jacira T; da Silva, Márcia M; Korn, Maria das Graças A; Welz, Bernhard; Vale, Maria Goreti R

    2007-10-31

    A method has been developed for the determination of cobalt, copper and manganese in green coffee using direct solid sampling electrothermal atomic absorption spectrometry (SS-ET AAS). The motivation for the study was that only a few elements might be suitable to determine the origin of green coffee so that the multi-element techniques usually applied for this purpose might not be necessary. The three elements have been chosen as test elements as they were found to be significant in previous investigations. A number of botanical certified reference materials (CRM) and pre-analyzed samples of green coffee have been used for method validation, and inductively coupled plasma optical emission spectrometry (ICP OES) after microwave-assisted acid digestion of the samples as reference method. Calibration against aqueous standards could be used for the determination of Mn and Co by SS-ET AAS, but calibration against solid CRM was necessary for the determination of Cu. No significant difference was found between the results obtained with the proposed method and certified or independently determined values. The limits of detection for Mn, Cu and Co were 0.012, 0.006 and 0.004mugg(-1) using SS-ET AAS and 0.015, 0.13 and 0.10mugg(-1) using ICP OES. Seven samples of Brazilian green coffee have been analyzed, and there was no significant difference between the values obtained with SS-ET AAS and ICP OES for Mn and Cu. ICP OES could not be used as a reference method for Co, as essentially all values were below the limit of quantification of this technique. PMID:19073113

  11. Flotation separation of iron, copper and lead in environmental samples and their determination by electrothermal atomic absorption spectrometry

    Complete text of publication follows. Some of the heavy metals are among the most harmful of the elemental pollutants and are of particular concern because of their toxicities to humans. Heavy metals include essential elements like iron as well as toxic metals like cadmium and mercury. Direct determination of trace heavy metals, by flame atomic absorption spectrometry (FAAS) or electrothermal atomic spectrometry (ETAAS) is not possible, because of their low concentrations and matrix effects. In order to know the accurate concentrations of trace heavy metals, enrichment processes are necessary. The most common, simple, rapid, low cost and effective method used for preconcentration is flotation. Only a small amount of surfactant, collector agent and tiny air bubbles is required to perform the proper flotation. Most of them have a tremendous affinity for sulfur and disrupt enzyme function by forming bonds with sulfur groups in enzymes. In this work a simple, sensitive and accurate procedure for flotation separation followed by ETAAS determination of Fe, Cu and Pb is proposed. 2-(2-methoxy phenyl) benzimidazole was used as the new collector agent. The optimum conditions of flotation were studied and important parameters were optimized. The experiment was done at pH =5. The linear ranges are 0-58, 0.350, 0-28 μg L-1 for Fe, Cu, and Pb respectively. The detection limits of the method for Fe, Cu and Pb are 0.08, 0.001, 0.08 μg L-1 respectively. This method was successfully applied for separation and determination of Cu, Pb and Fe in some environmental samples.

  12. [Determination of aluminum in wheat flour food by microwave digestion-high resolution continuum source graphite furnace atomic absorption spectrometry].

    Ren, Ting; Zhao, Li-jiao; Zhong, Ru-gang

    2011-12-01

    The contents of aluminum (Al) in four kinds of wheat flour food (noodle, dumpling wrapper, twisted cruller and soda biscuit) were determined by high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) combined with microwave digestion. The samples were completely digested by the mixture of HNO3 and H2O2 in closed polytetrafluoroethylene (PTFE) vessels. The conditions for microwave digestion, pyrolysis temperature and atomization temperature were optimized. The optimum experimental conditions were determined as follows. The microwave digestion was performed with HNO3/H2O2 7:1 (volume ratio), microwave power 1000 W and 190 degrees C for 40 minutes. The optimum pyrolysis temperature was 1350 degrees C and the optimum atomization temperature was 2400 degrees C. Magnesium nitrate solution with the concentration of 1 g x L(-1) was used as the matrix modifier. The correlation coefficient for the standard curve was 0.9999, the relative standard deviation (RSD) was from 1.7% to 2.4%, and the recovery for the samples was from 98.16% to 102.67%. The assay method for the determination of Al in wheat flour food established in this study has referential importance for the constituent of the correlated food standards. PMID:22295801

  13. Determination of bismuth in environmental samples by slurry sampling graphite furnace atomic absorption spectrometry using combined chemical modifiers.

    Dobrowolski, Ryszard; Dobrzyńska, Joanna; Gawrońska, Barbara

    2015-01-01

    Slurry sampling graphite furnace atomic absorption spectrometry technique was applied for the determination of Bi in environmental samples. The study focused on the effect of Zr, Ti, Nb and W carbides, as permanent modifiers, on the Bi signal. Because of its highest thermal and chemical stability and ability to substantially increase Bi signal, NbC was chosen as the most effective modifier. The temperature programme applied for Bi determination was optimized based on the pyrolysis and atomization curves obtained for slurries prepared from certified reference materials (CRMs) of the soil and sediments. To overcome interferences caused by sulfur compounds, Ba(NO₃)₂ was used as a chemical modifier. Calibration was performed using the aqueous standard solutions. The analysis of the CRMs confirmed the reliability of the proposed analytical method. The characteristic mass for Bi was determined to be 16 pg with the detection limit of 50 ng/g for the optimized procedure at the 5% (w/v) slurry concentration. PMID:25384374

  14. Determination of vanadium in soils and sediments by the slurry sampling graphite furnace atomic absorption spectrometry using permanent modifiers.

    Dobrowolski, Ryszard; Adamczyk, Agnieszka; Otto, Magdalena

    2013-09-15

    A new analytical procedure for vanadium (V) determination in soils and sediments by the slurry sampling graphite furnace atomic absorption spectrometry (slurry sampling GFAAS) using the mixed permanent modifiers is described. Moreover, the comparison of action of the modifiers based on the iridium (Ir) and carbide-forming elements: tungsten (W) and niobium (Nb) deposited on the graphite tubes is studied, especially in terms of their analytical utility and determination sensitivity. The mechanism of their action was investigated using an X-ray diffraction technique (XRD) and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray detector (EDX). Finally, the mixture of 0.3 μg of Ir and 0.04 μg of Nb was used for the graphite tube permanent modification. The analytical procedure was optimized on the basis of the data from pyrolysis and atomization temperature curves studies. The results obtained for the four certified reference materials (marine sediments: PACS-1 and MESS-1, lake sediment: SL-1, soil: San Joaquin Soil SRM 2709), using the slurry sampling GFAAS and the standard calibration method, were in good agreement with the certified values. The detection and quantification limits and characteristic mass calculated for the proposed procedure were 0.04 µg/g, 0.16 µg/g and 11.9 pg, respectively. The precision (RSD% less than 8%) and the accuracy of vanadium determination in the soil and sediment samples were acceptable. PMID:23708618

  15. Slurry sampling for the determination of thallium in soils and sediments by graphite furnace atomic absorption spectrometry

    Dobrowolski, R. [Analytical Laboratory, Faculty of Chemistry, Maria Curie-Sklodowska University, M.C. Sklodowska Sq.3, 20-031 Lublin (Poland)

    2002-12-01

    The analytical conditions for thallium determination in soils and sediments by slurry sampling graphite furnace atomic absorption spectrometry were studied and optimized. Elimination of a strong background for soils rich in organic materials by application of tungsten carbides coated graphite tubes/platforms was studied in detail. Tungsten carbides increased the maximum permissible pyrolysis temperature from 300 to 900 C. The mechanism of tungsten carbide formation on different graphite surfaces was proposed. Application of a strong basic anion-exchange resin for interference elimination in thallium determination in marine sediments was described. Calibration was performed directly using aqueous standards both for soil and sediment analysis. Analysis of CRM confirmed the reliability of the approach. The precision and accuracy of thallium determination by the described method for soils and sediments was acceptable. A characteristic mass of 13.8 pg was obtained and the limit of detection for the proposed method was around 0.06 {mu}g g{sup -1} Tl. (orig.)

  16. Determination of Cd, Pb and As in sediments of the Sava River by electrothermal atomic absorption spectrometry

    SIMONA MURKO

    2010-01-01

    Full Text Available The applicability of nitric acid, palladium nitrate and a mixture of palladium and magnesium nitrate as matrix modifiers were estimated for the accurate and reproducible determination of cadmium (Cd, lead (Pb and arsenic (As in sediments of the Sava River by electrothermal atomic absorption spectrometry, ETAAS. Decomposition of the samples was done in a closed vessel microwave-assisted digestion system using nitric, hydrochloric and hydrofluoric acids, followed by the addition of boric acid to convert the fluorides into soluble complexes. The parameters for the determination of Cd, Pb and As in sediments were optimised for each individual element and for each matrix modifier. In addition, two sediment reference materials were also analysed. In determination of Cd and Pb, nitric acid was found to be the most appropriate matrix modifier. The accurate and reliable determination of Cd and Pb in sediments was possible also in the presence of boric acid. The use of a mixture of palladium and magnesium nitrate efficiently compensated for matrix effects and enabled the accurate and reliable determination of As in the sediments. Quantification of Cd and As was performed by calibration using acid matched standard solutions, while the standard addition method was applied for the quantification of Pb. The repeatability of the analytical procedure for the determination of Cd, Pb and As in sediments was ±5 % for Cd, ±4 % for Pb and ±2 % for As. The LOD values of the analytical procedure were found to be 0.05 mg/kg for Cd and 0.25 mg/kg for Pb and As, while the LOQ values were 0.16 mg/kg for Cd and 0.83 mg/kg for Pb and As. Finally, Cd, Pb and As were successfully determined in sediments of the Sava River in Slovenia.

  17. International comparison of Cd content in a quality control material of Navajuelas (Tagelus dombeii) determined by anodic stripping voltammetry, atomic absorption spectrometry and neutron activation analysis

    Queirolo, F. (Universidad Catolica del Norte, Antofagasta (Chile). Dept. of Chemistry Forschungszentrum Juelich GmbH (Germany, F.R.). Inst. fuer Angewandte Physikalische Chemie Universidad de Extremadura, Badajoz (Spain). Dept. of Analytical Chemistry and Electrochemistry); Ostapczuk, P. (Forschungszentrum Juelich GmbH (Germany, F.R.). Inst. fuer Angewandte Physikalische Chemie); Valenta, P.; Stegen, S. (Forschungszentrum Juelich GmbH (Germany, F.R.). Inst. fuer Angewandte Physikalische Chemie Universidad de Extremadura, Badajoz (Spain). Dept. of Analytical Chemistry and Electrochemistry); Marin, C.; Vinagre, F.; Sanchez, A. (Universidad de Extremadura, Badajoz (Spain). Dept. of Analytical Chemistry and Electrochemistry)

    1991-05-01

    The determination of Cd was performed by neutron activation analysis (NAA), atomic absorption spectrometry (AAS) with flame or in the electrothermal mode and anodic stripping voltammetry in the differential pulse mode (DPASV) and the square wave mode (SWASV). (orig./EF).

  18. Investigations into the Role of Modifiers for Entrapment of Hydrides in Flow Injection Hydride Generation Electrothermal Atomic Absorption Spectrometry as Exemplified for the Determination of Germanium

    Hilligsøe, Bo; Andersen, Jens Enevold Thaulov; Hansen, Elo Harald

    1997-01-01

    Pd-conditioned graphite tubes, placed in the furnace of an atomic absorption spectrometry instrument, are used for entrapment of germane as generated in an associated flow injection system. Two different approaches are tested with the ultimate aim to allow multiple determinations, that is...

  19. Determination of platinum and palladium in road dust after their separation on immobilized fungus by electrothermal atomic absorption spectrometry

    Woinska, Sylwia; Godlewska-Zylkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

    2011-07-15

    A flow solid phase extraction procedure based on biosorption of Pt(IV) and Pd(II) on Aspergillus sp. immobilized on cellulose resin Cellex-T was proposed for the separation and preconcentration of Pt and Pd before their determination by electrothermal atomic absorption spectrometry (ETAAS). The analytical conditions including sample pH, eluent type, flow rates of sample and eluent solutions were examined. The analytes were selectively retained on the biosorbent in acidic medium (pH 1) and subsequently eluted from the column with 1 mL of thiourea solution (0.25 mol L{sup -1} thiourea in 0.3 mol L{sup -1} HCl). The reproducibility of the procedure was below 5%. The limit of detection of the method was 0.020 ng mL{sup -1} for Pt and 0.012 ng mL{sup -1} for Pd. The method validation was performed by analysis of certified reference materials BCR-723 (tunnel dust) and SARM-76 (platinum ore). The developed separation procedure was applied to the determination of Pt and Pd in road dust samples by ETAAS. The applied biosorbent is characterized by high sorption capacity: 0.47 mg g{sup -1} for Pt and 1.24 mg g{sup -1} for Pd.

  20. Determination of trace copper in food samples by flame atomic absorption spectrometry after solid phase extraction on modified soybean hull

    Soybean hull was chemically modified with citric acid and used as a solid phase extraction adsorbent for the determination of trace amounts of Cu2+ in food samples by flame absorption spectrometry (FAAS). The effect of pH, sample flow rate and volume, elution flow rate and volume and co-existing ions on the recovery of the analyte were investigated. The results showed that Cu2+ could be adsorbed on the modified soybean hull at pH 8.0 and eluted by 2.0 mL of 1.0 mol L-1 HCl. Under the optimized conditions, the adsorption capacity of modified soybean hull was found to be 18.0 mg g-1 for Cu2+. The detection limit of the proposed method was 0.8 ng mL-1 for Cu2+ with an enrichment factor of 18. The analytical result for the certified reference tea sample (GBW07605) was in a good agreement with the certified value. The proposed method has also been successfully applied to the determination of trace Cu2+ in dried sweet potato, lake water and milk powder, the recovery of Cu2+ for spiked samples was between 91% and 109.6%.

  1. Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry

    A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL-1. The relative standard deviation (n = 7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin.

  2. Determination of total arsenic in coal and wood using oxygen flask combustion method followed by hydride generation atomic absorption spectrometry

    A simple and sensitive procedure for the determination of total arsenic in coal and wood was conducted by use of oxygen flask combustion (OFC) followed by hydride generation atomic absorption spectrometry (HGAAS). The effect of various items (composition of absorbent, standing time between the combustion and filtration, particle size and mass of sample) was investigated. Under the optimized conditions of the OFC method, nine certified reference materials were analyzed, and the values of arsenic concentration obtained by this method were in good accordance with the certified values. The limit of detection (LOD) and relative standard deviation (RSD) of the method were 0.29 μg g-1 and less than 8%, respectively. In addition, eight kinds of coals and four chromated copper arsenate (CCA)-treated wood wastes were analyzed by the present method, and the data were compared to those from the microwave-acid digestion (MW-AD) method. The determination of arsenic in solid samples was discussed in terms of applicable scope and concentration range of arsenic.

  3. Determination of essential and toxic elements in commercial baby foods by instrumental neutron activation analysis and atomic absorption spectrometry

    The World Health Organization recommends that infants should be breast fed exclusively for at least six months after birth. After this period, it is recommended to start introducing complementary foods, in order to meet the child's nutritional, mineral and energy needs. Commercial food products for infants form an important part of the diet for many babies. Thus, it is very important that such food contains sufficient amounts of minerals. Inadequate complementary feeding is a major cause of high rates of infant malnutrition in developing countries. In this study, essential elements: Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Se and Zn and toxic elements: As, Cd, Hg levels were determined in twenty seven different commercial infant food product samples by Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectrometry (AAS). In order to validate both methodologies the reference material: INCT MPH-2 Mixed Polish Herbs and NIST - SRM 1577b Bovine Liver by INAA and NIST - SRM 1548th Typical Diet and NIST - SRM 1547 Peach Leaves by AAS were analyzed. The twenty seven baby food samples were acquired from Sao Paulo city supermarkets and stores. Essential and toxic elements were determined. Most of the essential element concentrations obtained were lower than the World Health Organization requirements, while concentrations of toxic elements were below the tolerable upper limit. These low essential element concentrations in these samples indicate that infants should not be fed only with commercial complementary foods. (author)

  4. Dispersive Liquid-Liquid Microextraction of Bismuth in Various Samples and Determination by Flame Atomic Absorption Spectrometry

    Teslima Daşbaşı

    2016-01-01

    Full Text Available A dispersive liquid-liquid microextraction method for the determination of bismuth in various samples by flame atomic absorption spectrometry is described. In this method, crystal violet was used as counter positive ion for BiCl4- complex ion, chloroform as extraction solvent, and ethanol as disperser solvent. The analytical parameters that may affect the extraction efficiency like acidity of sample, type and amount of extraction and disperser solvents, amount of ligand, and extraction time were studied in detail. The effect of interfering ions on the analyte recovery was also investigated. The calibration graph was linear in the range of 0.040–1.00 mg L−1 with detection limit of 4.0 μg L−1 (n=13. The precision as relative standard deviation was 3% (n=11, 0.20 mg L−1 and the enrichment factor was 74. The developed method was applied successfully for the determination of bismuth in various water, pharmaceutical, and cosmetic samples and the certified reference material (TMDA-64 lake water.

  5. Determination of molybdenum in plants by vortex-assisted emulsification solidified floating organic drop microextraction and flame atomic absorption spectrometry

    A fast and sensitive procedure for extraction and preconcentration of molybdenum in plant samples based on solidified floating organic drop microextraction combined with flame atomic absorption spectrometry and discrete nebulization was developed. 8-Hydroxyquinoline (8-HQ) was used as complexing agent. The experimental conditions established were: 0.5% m v−1 of 8-HQ, 60 μL of 1-undecanol as the extractant phase, 2 min vortex extraction time, centrifugation for 2 min at 2000 rpm, 10 min into an ice bath and discrete nebulization by introducing 200 μL of solution. The calibration curve was linear from 0.02 to 4.0 mg L−1 with a limit of detection of 4.9 μg L−1 and an enhancement factor of 67. The relative standard deviations for ten replicate measurements of 0.05 and 1.0 mg L−1 Mo were 6.0 and 14.5%, respectively. The developed procedure was applied for determining molybdenum in corn samples and accuracy was proved using certified reference materials. - Highlights: ► Molybdenum was determined in plants by flame AAS. ► Flame AAS sensitivity was improved using microextraction and discrete nebulization. ► The developed procedure can be easily implemented in routine analysis. ► Green chemistry principles are followed

  6. Dispersive Liquid-Liquid Microextraction of Bismuth in Various Samples and Determination by Flame Atomic Absorption Spectrometry.

    Daşbaşı, Teslima; Kartal, Şenol; Saçmacı, Şerife; Ülgen, Ahmet

    2016-01-01

    A dispersive liquid-liquid microextraction method for the determination of bismuth in various samples by flame atomic absorption spectrometry is described. In this method, crystal violet was used as counter positive ion for BiCl4 (-) complex ion, chloroform as extraction solvent, and ethanol as disperser solvent. The analytical parameters that may affect the extraction efficiency like acidity of sample, type and amount of extraction and disperser solvents, amount of ligand, and extraction time were studied in detail. The effect of interfering ions on the analyte recovery was also investigated. The calibration graph was linear in the range of 0.040-1.00 mg L(-1) with detection limit of 4.0 μg L(-1) (n = 13). The precision as relative standard deviation was 3% (n = 11, 0.20 mg L(-1)) and the enrichment factor was 74. The developed method was applied successfully for the determination of bismuth in various water, pharmaceutical, and cosmetic samples and the certified reference material (TMDA-64 lake water). PMID:26881186

  7. Evaluation of four sample treatments for determination of platinum in automotive catalytic converters by graphite furnace atomic absorption spectrometry

    Conventional and microwave assisted digestion, both using aqua regia, alkaline fusion with lithium metaborate and aqueous slurries were evaluated as sample treatments for determination of Pt in automotive catalytic converters by Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). Determination of platinum by GF-AAS in samples of the catalytic converter's substrates, prepared by the four methods described, indicates that the highest platinum concentration i.e. maximum Pt extraction in the range of 748 ± 15-998 ± 10 μg mL-1, is obtained for samples dissolved by alkaline fusion, closely followed by analysis of aqueous plus Triton X-100 slurries 708 ± 14-958 ± 10 μg mL-1, while neither one of the acid digestion procedures achieved total dissolution of the samples. Slurry analysis is thus shown to be a viable alternative and is recommended, based on its speed and ease of implementation. Aqueous standards calibration curves and the standard addition methods were also compared. The results showed that no appreciable matrix effects are present, regardless of the sample preparation procedure used. Precision of the measurements, expressed as percentage relative standard deviation, ranged between 2.5 to 4.9%. Accuracy of the results was assessed by recovery tests which rendered values between 98.9 and 100.9%

  8. Determination of molybdenum in plants by vortex-assisted emulsification solidified floating organic drop microextraction and flame atomic absorption spectrometry

    Oviedo, Jenny A.; Fialho, Lucimar L.; Nóbrega, Joaquim A., E-mail: djan@terra.com.br

    2013-08-01

    A fast and sensitive procedure for extraction and preconcentration of molybdenum in plant samples based on solidified floating organic drop microextraction combined with flame atomic absorption spectrometry and discrete nebulization was developed. 8-Hydroxyquinoline (8-HQ) was used as complexing agent. The experimental conditions established were: 0.5% m v{sup −1} of 8-HQ, 60 μL of 1-undecanol as the extractant phase, 2 min vortex extraction time, centrifugation for 2 min at 2000 rpm, 10 min into an ice bath and discrete nebulization by introducing 200 μL of solution. The calibration curve was linear from 0.02 to 4.0 mg L{sup −1} with a limit of detection of 4.9 μg L{sup −1} and an enhancement factor of 67. The relative standard deviations for ten replicate measurements of 0.05 and 1.0 mg L{sup −1} Mo were 6.0 and 14.5%, respectively. The developed procedure was applied for determining molybdenum in corn samples and accuracy was proved using certified reference materials. - Highlights: ► Molybdenum was determined in plants by flame AAS. ► Flame AAS sensitivity was improved using microextraction and discrete nebulization. ► The developed procedure can be easily implemented in routine analysis. ► Green chemistry principles are followed.

  9. Evaluation of four sample treatments for determination of platinum in automotive catalytic converters by graphite furnace atomic absorption spectrometry

    Puig, Ana I.; Alvarado, José I.

    2006-09-01

    Conventional and microwave assisted digestion, both using aqua regia, alkaline fusion with lithium metaborate and aqueous slurries were evaluated as sample treatments for determination of Pt in automotive catalytic converters by Graphite Furnace Atomic Absorption Spectrometry (GF-AAS). Determination of platinum by GF-AAS in samples of the catalytic converter's substrates, prepared by the four methods described, indicates that the highest platinum concentration i.e. maximum Pt extraction in the range of 748 ± 15-998 ± 10 μg mL - 1 , is obtained for samples dissolved by alkaline fusion, closely followed by analysis of aqueous plus Triton X-100 slurries 708 ± 14-958 ± 10 μg mL - 1 , while neither one of the acid digestion procedures achieved total dissolution of the samples. Slurry analysis is thus shown to be a viable alternative and is recommended, based on its speed and ease of implementation. Aqueous standards calibration curves and the standard addition methods were also compared. The results showed that no appreciable matrix effects are present, regardless of the sample preparation procedure used. Precision of the measurements, expressed as percentage relative standard deviation, ranged between 2.5 to 4.9%. Accuracy of the results was assessed by recovery tests which rendered values between 98.9 and 100.9%.

  10. Determination of trace copper in food samples by flame atomic absorption spectrometry after solid phase extraction on modified soybean hull

    Xiang Guoqiang, E-mail: xianggq@126.com [School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001 (China); Zhang Yingming; Jiang Xiuming; He Lijun; Fan Lu; Zhao Wenjie [School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001 (China)

    2010-07-15

    Soybean hull was chemically modified with citric acid and used as a solid phase extraction adsorbent for the determination of trace amounts of Cu{sup 2+} in food samples by flame absorption spectrometry (FAAS). The effect of pH, sample flow rate and volume, elution flow rate and volume and co-existing ions on the recovery of the analyte were investigated. The results showed that Cu{sup 2+} could be adsorbed on the modified soybean hull at pH 8.0 and eluted by 2.0 mL of 1.0 mol L{sup -1} HCl. Under the optimized conditions, the adsorption capacity of modified soybean hull was found to be 18.0 mg g{sup -1} for Cu{sup 2+}. The detection limit of the proposed method was 0.8 ng mL{sup -1} for Cu{sup 2+} with an enrichment factor of 18. The analytical result for the certified reference tea sample (GBW07605) was in a good agreement with the certified value. The proposed method has also been successfully applied to the determination of trace Cu{sup 2+} in dried sweet potato, lake water and milk powder, the recovery of Cu{sup 2+} for spiked samples was between 91% and 109.6%.

  11. Determination of antimony in sediments and soils by slurry sampling graphite furnace atomic absorption spectrometry using a permanent chemical modifier

    Dobrowolski, Ryszard, E-mail: rdobrow@poczta.umcs.lublin.pl; Adamczyk, Agnieszka; Otto, Magdalena; Dobrzynska, Joanna

    2011-07-15

    For comparison of action of mixed permanent modifiers Ir/Nb and Ir/W, the influence of the amounts of modifier components was studied and the atomic absorption pyrolysis and atomization curves were determined with different modifiers. The optimum amounts of modifier components were 30 {mu}g Ir and 40 {mu}g of Nb that were deposited onto the L'vov platform in advance to analytical measurements. The long-term performance of the Ir and Nb permanent modifiers was derived from the investigations by scanning electron microscopy and energy dispersive X-ray spectrometry. The soil and sediment slurries were prepared in 4% hydrofluoric acid and 6% suspension of polytetrafluoroethylene in order to remove the high concentration of silica during the pyrolysis step of 900 deg. C. The calibration was made by using aqueous standards. The analysis of certified reference materials confirmed the accuracy and reliability of the proposed analytical approach. The precision of Sb determination was characterized with less than 6% RSD.

  12. An automatic countercurrent liquid-liquid micro-extraction system coupled with atomic absorption spectrometry for metal determination.

    Mitani, Constantina; Anthemidis, Aristidis N

    2015-02-01

    A novel and versatile automatic sequential injection countercurrent liquid-liquid microextraction (SI-CC-LLME) system coupled with atomic absorption spectrometry (FAAS) is presented for metal determination. The extraction procedure was based on the countercurrent flow of aqueous and organic phases which takes place into a newly designed lab made microextraction chamber. A noteworthy feature of the extraction chamber is that it can be utilized for organic solvents heavier or lighter than water. The proposed method was successfully demonstrated for on-line lead determination and applied in environmental water samples using an amount of 120 μL of chloroform as extractant and ammonium diethyldithiophosphate as chelating reagent. The effect of the major experimental parameters including the volume of extractant, as well as the flow rate of aqueous and organic phases were studied and optimized. Under the optimum conditions for 6 mL sample consumption an enhancement factor of 130 was obtained. The detection limit was 1.5 μg L(-1) and the precision of the method, expressed as relative standard deviation (RSD) was 2.7% at 40.0 μg L(-1) Pb(II) concentration level. The proposed method was evaluated by analyzing certified reference materials and spiked environmental water samples. PMID:25435230

  13. Indium determination by spectral overlappings of lines in atomic absorption spectrometry

    A molybdenum hollow-cathode lamp filled with neon can be used to determine indium. Characteristic concentration for this element is 4.5 mg/L in the 325 nm spectral region for the Mo(I) 325.621 nm line. In addition, values of 0.4 mg/L and 0.3 mg/L are obtained with the Mo(I) 410.215 nm and Ne(I) 451.151 nm lines, respectively. These spectral overlappings allow the determination of indium in silver-cadmium-indium alloys. (Author)

  14. Determination of mercury in gasoline by cold vapor atomic absorption spectrometry with direct reduction in microemulsion media

    Brandão, Geisamanda Pedrini; de Campos, Reinaldo Calixto; Luna, Aderval Severino

    2005-06-01

    The determination of Hg in gasoline by cold vapor atomic absorption spectrometry, after direct aqueous NaBH 4 reduction in a three-component (microemulsion) medium, was investigated. Microemulsions were prepared by mixing gasoline with propan-1-ol and 50% v / v HNO 3 at a 20 : 15 : 1 volume ratio. A long-term homogeneous system was immediately formed this way. After reduction, the Hg vapor generated in a reaction flask was transported to an intermediate K 2Cr 2O 7/H 2SO 4 trap solution in order to avoid poisoning of the Au-Pt trap by the gasoline vapors. A second reduction step was then conducted and the generated Hg vapor transported to the Au-Pt trap, followed by thermal release of Hg 0 and atomic absorption measurement. Purified N 2 was used as purge and transport gas. After multivariate optimization by central composite design calibration graphs showed coefficients of correlation of 0.9999 and a characteristic mass of 2 ng was obtained. Typical coefficients of variation of 5% and 6% were found for ten consecutive measurements at concentration levels of 1 and 8 μg L -1 of Hg 2+, respectively. The limit of detection was 0.10 μg L -1 (0.14 μg kg -1) in the original sample. A total measurement cycle took 11 min, permitting duplicate analysis of 3 samples per hour. The results obtained with the proposed procedure in the analysis of commercial gasoline samples were in agreement with those obtained by a comparative procedure. Gasoline samples of the Rio de Janeiro city have shown Hg concentrations below 0.27 μg L -1.

  15. Determination of mercury in gasoline by cold vapor atomic absorption spectrometry with direct reduction in microemulsion media

    The determination of Hg in gasoline by cold vapor atomic absorption spectrometry, after direct aqueous NaBH4 reduction in a three-component (microemulsion) medium, was investigated. Microemulsions were prepared by mixing gasoline with propan-1-ol and 50% v / v HNO3 at a 20 : 15 : 1 volume ratio. A long-term homogeneous system was immediately formed this way. After reduction, the Hg vapor generated in a reaction flask was transported to an intermediate K2Cr2O7/H2SO4 trap solution in order to avoid poisoning of the Au-Pt trap by the gasoline vapors. A second reduction step was then conducted and the generated Hg vapor transported to the Au-Pt trap, followed by thermal release of Hg0 and atomic absorption measurement. Purified N2 was used as purge and transport gas. After multivariate optimization by central composite design calibration graphs showed coefficients of correlation of 0.9999 and a characteristic mass of 2 ng was obtained. Typical coefficients of variation of 5% and 6% were found for ten consecutive measurements at concentration levels of 1 and 8 μg L-1 of Hg2+, respectively. The limit of detection was 0.10 μg L-1 (0.14 μg kg-1) in the original sample. A total measurement cycle took 11 min, permitting duplicate analysis of 3 samples per hour. The results obtained with the proposed procedure in the analysis of commercial gasoline samples were in agreement with those obtained by a comparative procedure. Gasoline samples of the Rio de Janeiro city have shown Hg concentrations below 0.27 μg L-1

  16. Determination of manganese in diesel, gasoline and naphtha by graphite furnace atomic absorption spectrometry using microemulsion medium for sample stabilization

    Brandão, Geisamanda Pedrini; de Campos, Reinaldo Calixto; de Castro, Eustáquio Vinicius Ribeiro; de Jesus, Honério Coutinho

    2008-08-01

    The determination of Mn in diesel, gasoline and naphtha samples at µg L - 1 level by graphite furnace atomic absorption spectrometry, after sample stabilization in a three-component medium (microemulsion) was investigated. Microemulsions were prepared by mixing appropriate volumes of sample, propan-1-ol and nitric acid aqueous solution, and a stable system was immediately and spontaneously formed. After multivariate optimization by central composite design the optimum microemulsion composition as well as the temperature program was defined. In this way, calibration using aqueous analytical solution was possible, since the same sensitivity was observed in the optimized microemulsion media and 0.2% v/v HNO 3. The use of modifier was not necessary. Recoveries at the 3 µg L - 1 level using both inorganic and organic Mn standards spiked solutions ranged from 98 to 107% and the limits of detection were 0.6, 0.5 and 0.3 µg L - 1 in the original diesel, gasoline and naphtha samples, respectively. The Mn characteristic mass 3.4 pg. Typical relative standard deviation ( n = 5) of 8, 6 and 7% were found for the samples prepared as microemulsions at concentration levels of 1.3, 0.8, and 1.5 µg L - 1 , respectively. The total determination cycle lasted 4 min for diesel and 3 min for gasoline and naphtha, equivalent to a sample throughput of 7 h - 1 for duplicate determinations in diesel and 10 h - 1 for duplicate determinations in gasoline and naphtha. Accuracy was also assessed by using other method of analysis (ASTM D 3831-90). No statistically significant differences were found between the results obtained with the proposed method and the reference method in the analysis of real samples.

  17. Cadmium and lead determination in foods by beam injection flame furnace atomic absorption spectrometry after ultrasound-assisted sample preparation

    A simple method for cadmium and lead determination in foods by beam injection flame furnace atomic absorption spectrometry (BIFF-AAS) was proposed. Food slurries were prepared by transferring an exact amount of cryogenic-ground homogenized material (50-100 mg) to centrifuge tubes, followed by addition of 5 ml (up to 2.8 mol l-1) nitric acid solution and sonication in an ultrasonic bath during 5-10 min. Thereafter, slurries were diluted with water to 10 ml, centrifuged during 5 min at 5400 rpm and 400 μl aliquot of the supernatant was analyzed by BIFF-AAS. The detection limits based on peak height measurements were 0.03 μg g-1 Cd and 1.6 μg g-1 Pb for 2% (m/v) slurry (200 mg/10 ml). For method validation, the certified reference materials Pig Kidney (BCR 186) and Rice Flour (NIES 10) were used. Quantitative cadmium and lead recoveries were obtained and no statistical differences were found at 95% level by applying the t-test

  18. Determination of methylmercury by electrothermal atomic absorption spectrometry using headspace single-drop microextraction with in situ hydride generation

    A new method is proposed for preconcentration and matrix separation of methylmercury prior to its determination by electrothermal atomic absorption spectrometry (ETAAS). Generation of methylmercury hydride (MeHgH) from a 5-ml solution is carried out in a closed vial and trapped onto an aqueous single drop (3-μl volume) containing Pd(II) or Pt(IV) (50 and 10 mg/l, respectively). The hydrogen evolved in the headspace (HS) after decomposition of sodium tetrahydroborate (III) injected for hydride generation caused the formation of finely dispersed Pd(0) or Pt(0) in the drop, which in turn, were responsible for the sequestration of MeHgH. A preconcentration factor of ca. 40 is achieved with both noble metals used as trapping agents. The limit of detection of methylmercury was 5 and 4 ng/ml (as Hg) with Pd(II) or Pt(IV) as trapping agents, and the precision expressed as relative standard deviation was about 7%. The preconcentration system was fully characterised through optimisation of the following variables: Pd(II) or Pt(IV) concentration in the drop, extraction time, pH of the medium, temperatures of both sample solution and drop, concentration of salt in the sample solution, sodium tetrahydroborate (III) concentration in the drop and stirring rate. The method has been successfully validated against two fish certified reference materials (CRM 464 tuna fish and CRM DORM-2 dogfish muscle) following selective extraction of methylmercury in 2 mol/l HCl medium

  19. Determination of molybdenum in plants by vortex-assisted emulsification solidified floating organic drop microextraction and flame atomic absorption spectrometry

    Oviedo, Jenny A.; Fialho, Lucimar L.; Nóbrega, Joaquim A.

    2013-08-01

    A fast and sensitive procedure for extraction and preconcentration of molybdenum in plant samples based on solidified floating organic drop microextraction combined with flame atomic absorption spectrometry and discrete nebulization was developed. 8-Hydroxyquinoline (8-HQ) was used as complexing agent. The experimental conditions established were: 0.5% m v- 1 of 8-HQ, 60 μL of 1-undecanol as the extractant phase, 2 min vortex extraction time, centrifugation for 2 min at 2000 rpm, 10 min into an ice bath and discrete nebulization by introducing 200 μL of solution. The calibration curve was linear from 0.02 to 4.0 mg L- 1 with a limit of detection of 4.9 μg L- 1 and an enhancement factor of 67. The relative standard deviations for ten replicate measurements of 0.05 and 1.0 mg L- 1 Mo were 6.0 and 14.5%, respectively. The developed procedure was applied for determining molybdenum in corn samples and accuracy was proved using certified reference materials.

  20. In-situ suspended aggregate microextraction of gold nanoparticles from water samples and determination by electrothermal atomic absorption spectrometry.

    Choleva, Tatiana G; Kappi, Foteini A; Tsogas, George Z; Vlessidis, Athanasios G; Giokas, Dimosthenis L

    2016-05-01

    This work describes a new method for the extraction and determination of gold nanoparticles in environmental samples by means of in-situ suspended aggregate microextraction and electrothermal atomic absorption spectrometry. The method relies on the in-situ formation of a supramolecular aggregate phase through ion-association between a cationic surfactant and a benzene sulfonic acid derivative. Gold nanoparticles are physically entrapped into the aggregate phase which is separated from the bulk aqueous solution by vacuum filtration on the surface of a cellulose filter in the form of a thin film. The film is removed from the filter surface and is dissociated into an acidified methanolic solution which is used for analysis. Under the optimized experimental conditions, gold nanoparticles can be efficiently extracted from water samples with recovery rates between 81.0-93.3%, precision 5.4-12.0% and detection limits as low as 75femtomolL(-1) using only 20mL of sample volume. The satisfactory analytical features of the method along with the simplicity indicate the efficiency of this new approach to adequately collect and extract gold nanoparticle species from water samples. PMID:26946014

  1. Determination of cadmium, aluminium, and copper in beer and products used in its manufacture by electrothermal atomic absorption spectrometry.

    Viñas, Pilar; Aguinaga, Nerea; López-García, Ignacio; Hernandez-Córdoba, Manuel

    2002-01-01

    Procedures were developed for determining cadmium, aluminium, and copper in beer and the products used in its manufacture by electrothermal atomic absorption spectrometry. Beer samples were injected into the furnace and solid samples were introduced as suspensions after preparation in a medium containing hydrogen peroxide, nitric acid, and ammonium dihydrogen phosphate for cadmium atomization. Calibration was performed with aqueous standards, and characteristic masses and detection limits were, respectively, 1 and 0.3 pg for cadmium, 18 and 5.4 pg for aluminium, and 5.6 and 6.8 pg for copper. Different samples of beer, wort, brewer's yeast, malt, raw grain, and hops were analyzed by the proposed procedures. Cadmium was found in low concentrations (0.001-0.08 microg/g and 0-1.3 ng/mL); copper (3-13 microg/g and 25-137 ng/mL) and aluminium (0.6-9 microg/g and 0.1-2 microg/mL) were found at higher levels. The reliability of the procedure was confirmed by comparing the results obtained with others based on microwave oven sample digestion, and by analyzing several certified reference materials. PMID:12083268

  2. On-line preconcentration and determination of mercury in biological and environmental samples by cold vapor-atomic absorption spectrometry

    An on-line procedure for the determination of traces of total mercury in environmental and biological samples is described. The present methodology combines cold vapor generation associated to atomic absorption spectrometry (CV-AAS) with preconcentration of the analyte on a minicolumn packed with activated carbon. The retained analyte was quantitatively eluted from the minicolumn with nitric acid. After that, volatile specie of mercury was generated by merging the acidified sample and sodium tetrahydroborate(III) in a continuous flow system. The gaseous analyte was subsequently introduced via a stream of Ar carrier into the atomizer device. Optimizations of both, preconcentration and mercury volatile specie generation variables were carried out using two level full factorial design (23) with 3 replicates of the central point. Considering a sample consumption of 25 mL, an enrichment factor of 13-fold was obtained. The detection limit (3σ) was 10 ng L-1 and the precision (relative standard deviation) was 3.1% (n = 10) at the 5 μg L-1 level. The calibration curve using the preconcentration system for mercury was linear with a correlation coefficient of 0.9995 at levels near the detection limit up to at least 1000 μg L-1. Satisfactory results were obtained for the analysis of mercury in tap water and hair samples

  3. Determination of toxic elements in different brands of cigarette by atomic absorption spectrometry using ultrasonic assisted acid digestion.

    Kazi, Tasneem Gul; Jalbani, Nusrat; Arain, Muhammad Balal; Jamali, Muhammad Khan; Afridi, Hassan Imran; Shah, Abdul Qadir

    2009-07-01

    In this paper, a sample preparation method based on ultrasonic assisted acid extraction (UAE) of Al, As, Cd, Ni and Pb from filler tobacco (FT) of different local branded (LBCs) and imported branded cigarettes (IBCs) consumed in Pakistan. Acid extracts obtained upon sonication were determined by atomic absorption spectrometry. Parameters influencing extraction such as pre-sonication time 10-15 min, sonication time 2-10 min, mass of sample 0.1-0.5 g, particle size VTL-2), and also applied a conventional acid digestion method (CDM) on same CRM, for comparative purpose. The average relative standard deviation of UAE method of CRM, ranged as 1.64-8.42% for N = 6, depending on the analytes. Extraction efficiencies for CRM were close to 97.1, 97.5, 98.5, 97.8 and 96.7 for Al, As, Cd, Ni and Pb, respectively. The concentrations of Al, As, Cd, Ni and Pb in cigarettes were present in all branded cigarettes, there is no any significance difference among LBCs and IBCs, except in few cases of LBCs, have high level of Cd and Al. Our results were compared with other worldwide studies. PMID:18600465

  4. The determination of wear metals in used lubricating oils by flame atomic absorption spectrometry using sulphanilic acid as ashing agent.

    Ekanem, E J; Lori, J A; Thomas, S A

    1997-11-01

    A simple and reliable ashing procedure is proposed for the preparation of used lubricating oil samples for the determination of calcium, magnesium, zinc, iron, chromium and nickel by flame atomic absorption spectrometry. Sulphanilic acid was added to oil samples and the mixture coked and the coke ashed at 550 degrees C. The solutions of the ash were analysed by flame AAS for the metals. The release of calcium, zinc, iron and chromium was improved by the addition of sulphanilic acid to samples. The relative standard deviations of metal concentration results in the initial oil samples were 1.5% for Ca (1500 mg l(-1) level), 0.3% for Mg (100 mg l(-1) level), 3.1% for Zn (1500 mg l(-1) level), 0.7% for Fe (500 mg l(-1) level), 0.02% for Cr (50 mg l(-1) level) and 0.002% for Ni (10 mg l(-1) level). The optimum sample size for efficient metal release was 20 g while the optimum sulphanilic acid to oil ratio was 0.05 g per gram of oil for Zn and Cr and 0.10 g for Ca and Fe. Results obtained by this procedure were highly reproducible and comparable with those obtained for the same samples using standard procedures. PMID:18966959

  5. Direct determination of P in biodiesel by high-resolution continuum source graphite furnace atomic absorption spectrometry

    The direct determination of P in biodiesel by high-resolution continuum source graphite furnace atomic absorption spectrometry has been investigated. A slow drying stage proved to be essential for good repeatability. Optimization was performed by a D optimal planning. The atomization temperature and modifier composition were the most relevant parameters. Thus, using a mixture of Pd (30 μg) and Mg(NO3)2 (20 μg) as the modifier, previously deposited onto the platform of the graphite tube and dried, a five step drying stage, and pyrolysis and atomization temperatures of 1000 and 2700 deg. C, respectively, a limit of detection of 0.5 μg g-1 was obtained. The analysis of biodiesel of different origins confirmed that external calibration with organic P standard solutions, diluted in P-free biodiesel, could be used. In this way, excellent agreement between the found and expected results was observed in the analysis of an ANP interlaboratorial exercise sample.

  6. Determination of calcium, copper, chromium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry

    The direct determinacao of calcium, copper, chomium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry with, air-acetylene flame is proposed. Effects of fuel/oxidant ratio, burner height and water content in the samples were investigated in detail. The method allows the determition of the elements with good precision (r.s.d. -1 for the elements tested. (author)

  7. Use of atomic absorption spectrometry to determine metallic impurities in coal

    The Brazilian Energetic Alternative Program expects the reduction of our dependence on foreign energy sources, by replacing fuel oil by mineral coal. Its gasification by means of nuclear energy must be also considered. However, the intensive burning of coal leads to serious environmental problems. During its combustion the release to atmosphere of toxic elements such as As, Hg, Pb, Zn and others is of great concern. Hence, it is important to have reliable analytical methods which can monitor inorganic constituents at various stages of coal production and utilization. The AAS is a suitable analytical technique to determine pollutants in coal because it is sensitive, simple, economic and cover a large range of concentration. The need of a previous treatment of sample is overcome by using an acid attack (HNO3 + HClO4 + HF) which has been proved to be rapid and efficient. (Author)

  8. Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

    Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 deg. C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 deg. C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g-1

  9. Determination of microamounts of potassium in sodium iodide by atomic absorption spectrometry

    Microdetermination of potassium in sodium iodide was developed by the standard addition method. Twenty grams of sample were dissolved in 50 ml of water in a quartz beaker. To the solution, 30 ml of concentrated hydrochloric acid and 30 ml of 30% hydrogen peroxide were added, and evaporated to dryness. By this process sodium iodide was converted into sodium chloride. The cake thus obtained was dissolved in water and diluted to exactly 200 ml. To 25 ml aliquots of the solution, the standard potassium and cesium chloride solutions were added and diluted to 50 ml with water; the concentration of potassium was 0 -- 1 mg/l and that of cesium 4 mM. These solutions were introduced into an air-propane flame and the absorbances were measured at 769.9 nm. During the conversion reaction, hydrochloric acid was completely decomposed, and remained hydrogen peroxide had no influence for absorbance, and other backgrounds were negligible. The linear calibration curve was obtained in the range 0 -- 2 mg of potassium per liter. Potassium in sodium iodide was determined by this method within the coefficient of variation of +-(20 -- 3)% in the range (1.7 -- 32.5) ppm. (author)

  10. Determination of cadmium and lead in urine by flame atomic absorption spectrometry after activated carbon enrichment

    In this study, ammonium pyrrolidine dithiocarbamate was used as a complexing agent in the enrichment step for the determination of cadmium and lead in urine. The recoveries were above 90% and the factors effecting recoveries, such as sample preparation, pH, amount of activated carbon, complexing reagent and the contact time, were studied. The interference effects from matrix components were compared after activated carbon enrichment. The calibration graphs were rectilinear for a range 1.2-80 μ l -1 and 1.6-53 μ l -1 for cadmium and lead, respectively. The relative standard deviations of the measurements (n=9) at concentration of 20 μ l -1 were 3% for cadmium and lead. Detection limits, defined as 3 s of blanks were 1.2 μ l -1 for cadmium and 1.6 μ l -1 for lead. The untreated urine (300 ml) was adjusted to pH 6 and 4 ml of 2% APDC solution were added to complex the metals. The mixture was stirred with 500 mg activated carbon for 40 min and next was filtered. The metals were leached with nitric acid. (author). 28 refs, 4 figs, 3 tabs

  11. Coacervative extraction of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry

    Hagarová, Ingrid, E-mail: hagarova@fns.uniba.sk; Bujdoš, Marek; Matúš, Peter; Kubová, Jana

    2013-10-01

    In this work, a relatively simple and sensitive method for separation/preconcentration of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry has been proposed. The method is based on the extraction of Pb–dithizone chelate with coacervates made up of lauric acid in the presence of potassium ions and methanol. Several important factors affecting extraction efficiency such as pH, concentration of lauric acid and dithizone, ionic strength, incubation and centrifugation time were investigated and optimized. After separation of aqueous bulk solution from surfactant-rich phase, the final extract was redissolved by using 500 μl of methanol acidified with 0.2 mol l{sup −1} HNO{sub 3}. Under the optimized conditions (using initial sample volume of 10 ml), enrichment factor of 17.0, detection limit of 0.12 μg l{sup −1}, quantification limit of 0.38 μg l{sup −1}, relative standard deviation of 4.2% (for 2 μg l{sup −1} of Pb; n = 26), linearity of the calibration graph in the range of 0.5–4.0 μg l{sup −1} (with correlation coefficient better than 0.995) were achieved. The method was validated by the analysis of certified reference material (TMDA-61). Extraction recoveries for the CRM, spiked model solutions and spiked natural water samples were in the range of 91–96%. Finally, the method was applied to the separation/preconcentration and determination of trace lead in natural waters. - Highlights: • The potential of coacervates for the extraction of metal ions is examined. • No difficulties in coupling of ETAAS with the proposed CAE are observed. • Achieved preconcentration factor results in enhanced sensitivity. • Analytical performance is confirmed by the reliable determination of trace Pb. • The proposed CAE is ecofriendly and efficient.

  12. RAPID AND SENSITIVE DETERMINATION OF PALLADIUM USING HOMOGENEOUS LIQUID-LIQUID MICROEXTRACTION VIA FLOTATION ASSISTANCE FOLLOWED BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

    Mohammad Rezaee; Reyhaneh Shadaniyan; Majid Haji Hosseini; Faezeh Khalilian

    2015-01-01

    A method for the determination of trace amounts of palladium was developed using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA) followed by graphite furnace atomic absorption spectrometry (GFAAS). Ammonium pyrrolidine dithiocarbamate (APDC) was used as a complexing agent. This was applied to determine palladium in three types of water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No...

  13. Determination of platinum traces contamination by graphite furnace atomic absorption spectrometry after preconcentration by cloud point extraction

    A simple and sensitive method is described for the determination of platinum surface contamination originating from cisplatin, carboplatin and oxaliplatin. Following extraction from swabs and preconcentration with the cloud point extraction (CPE) method, detection was by graphite furnace atomic absorption spectrometry (GFAAS). After desorption of platinum compounds from the swab, CPE involved on preconcentration of platinum in aqueous solution with diethyldithiocarbamate (DDTC) as chelating agent and Triton X-114 as extraction medium. DDTC is not only a chelating agent, but may also be a good candidate for the inactivation of platinum compounds. DDTC is recommended by the Word Health Organization (WHO) for the destruction of platinum-based anticancer drugs. The main factors affecting CPE efficiency, pH of the sample solution, concentrations of DDTC and Triton X-114, equilibration temperature and incubation time, were evaluated in order to enhance sensitivity of the method. The desorption of platinum compounds from the swab was investigated in parallel. Since platinum is bound to DDTC, it must exchange with copper in order to enhance platinum atomizing by GFAAS. A preconcentration factor of 29 was obtained for 10 mL of a platinum solution at 10 μg mL-1. In optimal conditions, the limit of detection was 0.2 ng mL-1, corresponding to 2.0 ng of platinum metal on the swab. Absorbance was linear between 0.7 and 15 ng mL-1. The proposed method was applied for the determination of surface contamination by platinum compounds with correct results.

  14. Coacervative extraction of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry

    Hagarová, Ingrid; Bujdoš, Marek; Matúš, Peter; Kubová, Jana

    2013-10-01

    In this work, a relatively simple and sensitive method for separation/preconcentration of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry has been proposed. The method is based on the extraction of Pb-dithizone chelate with coacervates made up of lauric acid in the presence of potassium ions and methanol. Several important factors affecting extraction efficiency such as pH, concentration of lauric acid and dithizone, ionic strength, incubation and centrifugation time were investigated and optimized. After separation of aqueous bulk solution from surfactant-rich phase, the final extract was redissolved by using 500 μl of methanol acidified with 0.2 mol l- 1 HNO3. Under the optimized conditions (using initial sample volume of 10 ml), enrichment factor of 17.0, detection limit of 0.12 μg l- 1, quantification limit of 0.38 μg l- 1, relative standard deviation of 4.2% (for 2 μg l- 1 of Pb; n = 26), linearity of the calibration graph in the range of 0.5-4.0 μg l- 1 (with correlation coefficient better than 0.995) were achieved. The method was validated by the analysis of certified reference material (TMDA-61). Extraction recoveries for the CRM, spiked model solutions and spiked natural water samples were in the range of 91-96%. Finally, the method was applied to the separation/preconcentration and determination of trace lead in natural waters.

  15. Speciation of Chromium in Water Samples with Homogeneous Liquid-Liquid Extraction and Determination by Flame Atomic Absorption Spectrometry

    A novel method was developed for the speciation of chromium in natural water samples based on homogeneous liquid-liquid extraction and determination by flame atomic absorption spectrometry (FAAS). In this method, Cr(III) reacts with a new Schiff's base ligand to form the hydrophobic complex, which is subsequently entrapped in the sediment phase, whereas Cr(VI) remained in aqueous phase. The Cr(VI) assay is based on its reduction to Cr(III) by the addition of sodium sulfite to the sample solution. Thus, separation of Cr(III) and Cr(VI) could be realized. Homogeneous liquid-liquid extraction based on the pH-independent phase-separation process was investigated using a ternary solvent system (water-tetrabutylammonium ion (TBA+)-chloroform) for the preconcentration of chromium. The phase separation phenomenon occurred by an ion-pair formation of TBA and perchlorate ion. Then sedimented phase was separated using a 100 μL micro-syringe and diluted to 1.0 mL with ethanol. The sample was introduced into the flame by conventional aspiration. After the optimization of complexation and extraction conditions such as pH = 9.5, [ligand] = 1.0 x 10-4 M, [TBA+] = 2.0 x 10-2 M, [CHCl3] = 100.0 μL and [ClO4-] = 2.0 x 10-2 M, a preconcentration factor (Va/Vs) of 100 was obtained for only 10 mL of the sample. The relative standard deviation was 2.8% (n = 10). The limit of detection was sufficiently low and lie at ppb level. The proposed method was applied for the extraction and determination of chromium in natural water samples with satisfactory results

  16. Trace-element determination in lichens of Cordoba (Argentina) using neutron activation analysis and atomic absorption spectrometry

    Ramalina ecklonii (Spreng.) Mey. and Flot. is a lichen widely distributed in Cordoba, a central province of Argentina. The ability of this lichen as an atmospheric pollution bioindicator has already been studied in relation to its physiological response to air pollutants. This work has to do with the study of R. ecklonii in terms of its capacity to accumulate heavy metals and other trace elements. The sampled area, located in the province of Cordoba, covered 50,000 km2 and was divided following a grid of 25 x 25 km. Lichens were collected at the intersecting points, no least than 500 m from main routes or highly populated centres and individuals were randomly gathered following the four cardinal directions and no more than 100 m from the geographically settled point. From each pool, three sub-samples were taken for independent analysis using atomic absorption spectrometry (AAS) and neutron activation analysis (NAA), for the determination of twenty nine elements (Cu, Ni, Mn, and Pb (AAS) and As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Rb, Sb, Sc, Sm, Ta, Tb, Th, U, Yb, and Zn (NAA). The quality of the determinations was checked using standard reference material and data sets were evaluated using descriptive statistics, correlation analysis, and factor analysis. The highest variation coefficients correspond to Ca, Cr, and Zn. The studied elements were identified as of physiological importance and as emitted by natural (soil and rocks) and anthropogenic sources (non-ferrous metallurgy, coal combustion, oil-fired plants, fossil fuel combustion and, other industries). (author)

  17. Simultaneous flow injection preconcentration of lead and cadmium using cloud point extraction and determination by atomic absorption spectrometry.

    Silva, Edson Luiz; Roldan, Paulo Dos Santos

    2009-01-15

    A flow injection (FI) micelle-mediated separation/preconcentration procedure for the determination of lead and cadmium by flame atomic absorption spectrometry (FAAS) has been proposed. The analytes reacted with 1-(2-thiazolylazo)-2-naphthol (TAN) to form hydrophobic chelates, which were extracted into the micelles of 0.05% (w/v) Triton X-114 in a solution buffered at pH 8.4. In the preconcentration stage, the micellar solution was continuously injected into a flow system with four mini-columns packed with cotton, glass wool, or TNT compresses for phase separation. The analytes-containing micelles were eluted from the mini-columns by a stream of 3molL(-1) HCl solution and the analytes were determined by FAAS. Chemical and flow variables affecting the preconcentration of the analytes were studied. For 15mL of preconcentrated solution, the enhancement factors varied between 15.1 and 20.3, the limits of detection were approximately 4.5 and 0.75microgL(-1) for lead and cadmium, respectively. For a solution containing 100 and 10microgL(-1) of lead and cadmium, respectively, the R.S.D. values varied from 1.6 to 3.2% (n=7). The accuracy of the preconcentration system was evaluated by recovery measurements on spiked water samples. The method was susceptible to matrix effects, but these interferences were minimized by adding barium ions as masking agent in the sample solutions, and recoveries from spiked sample varied in the range of 95.1-107.3%. PMID:18456398

  18. Automatic flow system for the sequential determination of copper in serum and urine by flame atomic absorption spectrometry

    In this work, a fully automated flow system exploiting the advantages of the association of multi-pumping, multicommutation, binary sampling and merging zones, to accomplish the sequential determination of copper in serum and urine by flame atomic absorption spectrometry, is described. The developed flow system allowed multiple tasks, such as serum samples preparation (samples and standard solutions viscosity adjustment), serum copper (SCu) measurement, urine copper (UCu) pre-concentration and its subsequent elution and measurement, to be carried out sequentially. The implemented flow manifold presented a modular configuration consisting on two quasi-independent modules, each one accountable for a specific sample manipulation and whose combined operation under computer control enabled the determination of copper in a wide concentrations range. Once optimised and with a sample consumption of about 0.250 mL of serum and 7 mL of urine, the developed flow system allowed linear calibration plots up to 5 mg L-1 with a detection limit of 0.035 mg L-1 for SCu and linear calibration plots up to 300 μg L-1 with a detection limit of 0.67 μg L-1 for UCu. The sampling rate varied according to the module employed and was about 360 determinations h-1 (SCu module), 12 determinations h-1 (UCu module) or 24 determinations h-1 (12 urine and 12 serum samples; UCu and SCu modules simultaneously). Repeatability studies (R.S.D.%, n = 10) showed good precision for UCu at concentrations of 25 μg L-1 (2.54%), 50 μg L-1 (0.90%) and 100 μg L-1 (1.62%) as well as for SCu at concentrations of 0.25 mg L-1 (8.11%), 1 mg L-1 (3.11%) and 5 mg L-1 (0.90%). A comparative evaluation showed a good agreement between the results obtained in the analysis of UCu and SCu (n = 18) by both the developed methodology and the reference procedures. Accuracy was further evaluated by means of the analysis of reference samples (SeronormTM Trace Elements Urine and SeronormTM Trace Elements Serum) and the

  19. Feasibility of using direct determination of cadmium and lead in fresh meat by electrothermal atomic absorption spectrometry for screening purposes

    A method for the direct determination of cadmium and lead in fresh meat for screening purposes is proposed using electrothermal atomic absorption spectrometry. The fresh meat samples were homogenized, weighed directly onto solid sampling platforms and introduced into a transversely heated solid sampling graphite tube. The main challenges associated with this procedure, such as weighing errors and optimization of the temperature program were investigated in detail. Calibration was performed against aqueous standards and two modifiers were investigated: 0.05% Pd + 0.03% Mg + 0.05% Triton X-100 and 0.01% Pd + 10% NH4NO3 + 0.05% Triton X-100. The former one is recommended due to the higher pyrolysis temperature obtained for cadmium and the better limits of detection of 1.9 μg kg-1 for lead and 0.13 μg kg-1 for cadmium, based on 10 mg of sample mass. The results obtained for cadmium and lead in two certified reference materials were statistically not different from the certified values on a 95% confidence level, indicating that calibration against aqueous standards is suitable for this application. In order to evaluate weighing errors the fresh samples were dried (at 60 deg. C) to constant weight; the results obtained with fresh and dried samples were in agreement, taking the loss of weight into consideration for the latter ones. The average relative standard deviation of 14% is in concordance with the results of others using fresh meat. Comparison with the digestion method adopted by the Brazilian Ministry of Agriculture shows no significant differences between the results at the 95% confidence level. This study shows that direct analysis of fresh meet can be applied as a rapid routine screening procedure for residue control in products of animal origin, helping the implementation and maintenance of sanitary control

  20. Determination of trace amounts of molybdenum in plant tissue by solvent extraction-atomic-absorption and direct-current plasma emission spectrometry.

    Lajunen, L H; Kubin, A

    1986-03-01

    Methods are presented for determination of molybdenum in plant tissue by flame and graphite-furnace atomic-absorption spectrometry and direct-current argon-plasma emission spectrometry. The samples are digested in HNO(3)-H(2)SO(4)-HC1O(4) mixture, and Mo is separated and concentrated by chelation and extraction. Three organic solvents (methyl isobutyl ketone, di-isobutyl ketone and isoamyl alcohol) and two ligands (8-hydroxyquinoline and toluene-3,4-dithiol) were studied. The procedure were tested on pine needle and birch leaf samples. PMID:18964076

  1. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6–4.3%), repeatability (4–9%), reproducibility (9–11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as

  2. Comparative Studies of the Determination of Divalent Cadmium, Lead and Copper in the Boiling Medicinal Herbs by Stripping Voltammetry and by Atomic Absorption Spectrometry

    Ahmed Hassan

    2009-01-01

    Full Text Available Cadmium, lead and copper were determined in ten Libyian boiling medicinal herbs samples by differential pulse anodic stripping voltammetry as well as by atomic absorption spectrometry. Voltammetric method was done at Hanging Mercury Dropping Electrode (HMDE in Briton-Robinson buffer solution of pH ~2.1 at 25± 0.1°C. The sample preparation was carried out by boiling 2.0g of a finely pulverized plant sample for 10 min, cooled, filtered and completed to 50 mL measuring flask by deionized water. The optimal preconcentration potentials and times for the detection of these metal ions in all sample solutions have been studied. The concentration of each metal ion was determined by the standard addition method. The statistical parameters i.e. slope, standard deviation, correlation coefficient and confidence have been calculated. The levels of Cd(II, Pb(II and Cu(II ranged from 0.006-0.103, 0.205-1.751 and 0.198-2.124 µg g-1 respectively. Copper was determined by Flame Atomic Absorption Spectrometry (FAAS and the mean level was ranged from 0.202-2.010 µg g-1 . On the other hand the mean levels obtained for determination of cadmium and lead by Graphite Furnace Atomic Absorption Spectrometry (GFAAS ranged from 0.006 to 0.085 and from 0.220-1.850 µg g-1 respectively.

  3. Trace mercury determination in drinking and natural water after preconcentration and separation by DLLME-SFO method coupled with cold vapor atomic absorption spectrometry

    Abdollahi Atousa; Amirkavehei Mooud; Gheisari Mohammad Mehdi; Tadayon Fariba

    2014-01-01

    A novel dispersive liquid–liquid microextraction based on solidification of floating organic drop (DLLME-SFO) for simultaneous separation/preconcentration of ultra trace amounts of mercury was used. A method based on amalgamation was used for collection of gaseous mercury on gold coated sand (Gold trap). The concentration of mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS). The DLLME-SFO behavior of mercury by using dithizone as complexing agent was systematically ...

  4. Determination of serum aluminum by electrothermal atomic absorption spectrometry: A comparison between Zeeman and continuum background correction systems

    Kruger, Pamela C. [Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, P.O. Box 509, Albany, NY 12201-0509 (United States); Parsons, Patrick J. [Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, P.O. Box 509, Albany, NY 12201-0509 (United States); Lead Poisoning/Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States)], E-mail: patrick.parsons@wadsworth.org

    2007-03-15

    Excessive exposure to aluminum (Al) can produce serious health consequences in people with impaired renal function, especially those undergoing hemodialysis. Al can accumulate in the brain and in bone, causing dialysis-related encephalopathy and renal osteodystrophy. Thus, dialysis patients are routinely monitored for Al overload, through measurement of their serum Al. Electrothermal atomic absorption spectrometry (ETAAS) is widely used for serum Al determination. Here, we assess the analytical performances of three ETAAS instruments, equipped with different background correction systems and heating arrangements, for the determination of serum Al. Specifically, we compare (1) a Perkin Elmer (PE) Model 3110 AAS, equipped with a longitudinally (end) heated graphite atomizer (HGA) and continuum-source (deuterium) background correction, with (2) a PE Model 4100ZL AAS equipped with a transversely heated graphite atomizer (THGA) and longitudinal Zeeman background correction, and (3) a PE Model Z5100 AAS equipped with a HGA and transverse Zeeman background correction. We were able to transfer the method for serum Al previously established for the Z5100 and 4100ZL instruments to the 3110, with only minor modifications. As with the Zeeman instruments, matrix-matched calibration was not required for the 3110 and, thus, aqueous calibration standards were used. However, the 309.3-nm line was chosen for analysis on the 3110 due to failure of the continuum background correction system at the 396.2-nm line. A small, seemingly insignificant overcorrection error was observed in the background channel on the 3110 instrument at the 309.3-nm line. On the 4100ZL, signal oscillation was observed in the atomization profile. The sensitivity, or characteristic mass (m{sub 0}), for Al at the 309.3-nm line on the 3110 AAS was found to be 12.1 {+-} 0.6 pg, compared to 16.1 {+-} 0.7 pg for the Z5100, and 23.3 {+-} 1.3 pg for the 4100ZL at the 396.2-nm line. However, the instrumental detection

  5. Ionic liquid ultrasound assisted dispersive liquid-liquid microextraction method for preconcentration of trace amounts of rhodium prior to flame atomic absorption spectrometry determination

    In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid-liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300 μL ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0-500.0 ng mL-1, the detection limit was 0.37 ng mL-1 (3Sb/m, n = 7) and the relative standard deviation was ±1.63% (n = 7, C = 200 ng mL-1). The results show that ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption.

  6. Flow injection on-line dilution for zinc determination in human saliva with electrothermal atomic absorption spectrometry detection

    An automated method is described for the determination of zinc in human saliva by electrothermal atomic absorption spectrometry (ET AAS) after on-line dilution of samples with a significant reduction of sample consumption per analysis (1) which allowed the introduction of 10 μL of either solution in the diluent stream. To avoid unnecessary waste of samples, the TBSI1 also permitted the recirculation of the solutions to their respective autosampler cups. The downstream diluted solution fills a home made sampling arm assembly. The sequential deposition of 20 μL aliquots of samples or standards on the graphite tube platform was carried out by air displacement with a similar time based solenoid injector (TBSI2). The dilution procedure and the injection of solutions into the atomizer are computer controlled and synchronized with the operation of the temperature program. Samples or standards solutions were submitted to two drying steps (at 90 and 130 deg. C), followed by pyrolysis and atomization at 700 and 1700 deg. C, respectively. The aqueous calibration was linear up to 120.0 μg L-1 for diluted standard solutions/samples and its slope was similar (p > 0.05) to the standard addition curve, indicating lack of matrix effect. The precision tested by repeated analysis of real saliva samples was less than 3% and the detection limit (3σ) was of 0.35 μg L-1. To test the accuracy of the proposed procedure, recovery tests were performed, obtaining mean recovery of added zinc of 97.8 ± 1.3%. Furthermore, Zn values estimated by the procedure developed in this work were compared with those obtained by a standard addition flame-AAS method applied to 20 randomly selected saliva samples. No significant differences (p > 0.05) were obtained between the two methods. Zinc levels in saliva samples from 44 healthy volunteers, 15 male and 29 female, with ages between 20 and 51 years (mean 30.50 ± 9.14 years) were in the range 22-98 μg L-1 (mean of 55 ± 17 μg L-1), similar to some

  7. Graphite filter atomizer in atomic absorption spectrometry

    Katskov, Dmitri A.

    2007-09-01

    Graphite filter atomizers (GFA) for electrothermal atomic absorption spectrometry (ETAAS) show substantial advantages over commonly employed electrothermal vaporizers and atomizers, tube and platform furnaces, for direct determination of high and medium volatility elements in matrices associated with strong spectral and chemical interferences. Two factors provide lower limits of detection and shorter determination cycles with the GFA: the vaporization area in the GFA is separated from the absorption volume by a porous graphite partition; the sample is distributed over a large surface of a collector in the vaporization area. These factors convert the GFA into an efficient chemical reactor. The research concerning the GFA concept, technique and analytical methodology, carried out mainly in the author's laboratory in Russia and South Africa, is reviewed. Examples of analytical applications of the GFA in AAS for analysis of organic liquids and slurries, bio-samples and food products are given. Future prospects for the GFA are discussed in connection with analyses by fast multi-element AAS.

  8. Determination of total sulfur concentrations in different types of vinegars using high resolution flame molecular absorption spectrometry.

    Ozbek, Nil; Akman, Suleyman

    2016-12-15

    Total sulfur concentrations in vinegars were determined using molecular absorption of carbon monosulfide (CS) determined with a high-resolution continuum source flame atomic absorption spectrometer. The molecular absorption of CS was measured at 258.056nm in an air-acetylene flame. Due to non-spectral interference, as well as the different sensitivities to some sulfur compounds, all sulfur species were oxidized to sulfate using a HNO3 and H2O2 mixture and the analyte addition technique was applied for quantification. The limit of detection (LOD) and limit of quantification (LOQ) were 11.6 and 38.6mgL(-1), respectively. The concentrations of sulfur in various vinegars ranged from ⩽LOD to 163.6mgL(-1). PMID:27451213

  9. Determination of sulfur in bovine serum albumin and L-cysteine using high-resolution continuum source molecular absorption spectrometry of the CS molecule

    Andrade-Carpente, Eva; Peña-Vázquez, Elena; Bermejo-Barrera, Pilar

    2016-08-01

    In this study, the content of sulfur in bovine serum albumin and L-cysteine was determined using high-resolution continuum source molecular absorption spectrometry of the CS molecule, generated in a reducing air-acetylene flame. Flame conditions (height above the burner, measurement time) were optimized using a 3.0% (v/v) sulfuric acid solution. A microwave lab station (Ethos Plus MW) was used for the digestion of both compounds. During the digestion step, sulfur was converted to sulfate previous to the determination. Good repeatability (4-10%) and analytical recovery (91-106%) was obtained.

  10. Implementation of suitable flow injection/sequential-sample separation/preconcentration schemes for determination of trace metal concentrations using detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    Hansen, Elo Harald; Wang, Jianhua

    Various preconditioning procedures encomprising appropriate separation/preconcentration schemes in order to obtain optimal sensitivity and selectivity characteristics when using electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are...

  11. Implementation of suitable flow injection/sequential-sample separation/preconcentration schemes for determination of trace metal concentrations using detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    Hansen, Elo Harald; Wang, Jianhua

    2002-01-01

    Various preconditioning procedures encomprising appropriate separation/preconcentration schemes in order to obtain optimal sensitivity and selectivity characteristics when using electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS) are...

  12. Direct determination of fluorine in niobium oxide using slurry sampling electrothermal high-resolution continuum source molecular absorption spectrometry

    Aiming for a round-robin test, a new method for the direct determination of fluorine in niobium oxide has been developed. It is based on the use of high-resolution molecular absorption spectra of calcium mono-fluoride (CaF) generated in the graphite tube, combined with the slurry sampling technique. The absorption measurement was performed at the 606.44 nm CaF rotational line. By using graphite tubes with zirconium carbide (ZrC) modified platform, the molecular absorption sensitivity of CaF has been improved by a factor of 20, and no additional chemical modifier was necessary. Generally, non-spectral interferences were observed in the presence of HCl, H2SO4, and H3PO4. For HCl, additional spectral interference occurred due to an overlap of the absorption spectra of CaF and CaCl. However, due to the absence of these mentioned substances in the current material, such interferences do not exist for this application. The characteristic mass found for the CaF 606.44 nm line was 0.1 ng; the limit of detection was 5 mg fluorine per kg solid sample (3σ criterion). The results obtained by the method were within the range of certified values. Comparing to the classical method such as the pyrohydrolysis-photometric method, the developed new method showed clear advantages regarding sensitivity and specificity. The time requirement for one sample analysis was strongly shortened from several hours to only some minutes. - Highlights: • First time determination of fluorine in niobium oxide using the slurry sampling technique • Application of calcium fluoride molecular absorption in graphite tube with ZrC modification • Higher specificity, better sensitivity, and huge time saving compared with the classical method based on pyrohydrolysis • New method verified by successful participation in round robin test

  13. Direct determination of fluorine in niobium oxide using slurry sampling electrothermal high-resolution continuum source molecular absorption spectrometry

    Huang, Mao Dong; Becker-Ross, Helmut [Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Okruss, Michael, E-mail: michael.okruss@isas.de [Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Geisler, Sebastian; Florek, Stefan [Leibniz-Institut für Analytische Wissenschaften—ISAS—e.V., Department Berlin, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Richter, Silke; Meckelburg, Angela [BAM Federal Institute for Materials Research and Testing, Department of Analytical Chemistry, Reference Materials, Richard-Willstätter-Str. 11, 12489 Berlin (Germany)

    2014-04-01

    Aiming for a round-robin test, a new method for the direct determination of fluorine in niobium oxide has been developed. It is based on the use of high-resolution molecular absorption spectra of calcium mono-fluoride (CaF) generated in the graphite tube, combined with the slurry sampling technique. The absorption measurement was performed at the 606.44 nm CaF rotational line. By using graphite tubes with zirconium carbide (ZrC) modified platform, the molecular absorption sensitivity of CaF has been improved by a factor of 20, and no additional chemical modifier was necessary. Generally, non-spectral interferences were observed in the presence of HCl, H{sub 2}SO{sub 4}, and H{sub 3}PO{sub 4}. For HCl, additional spectral interference occurred due to an overlap of the absorption spectra of CaF and CaCl. However, due to the absence of these mentioned substances in the current material, such interferences do not exist for this application. The characteristic mass found for the CaF 606.44 nm line was 0.1 ng; the limit of detection was 5 mg fluorine per kg solid sample (3σ criterion). The results obtained by the method were within the range of certified values. Comparing to the classical method such as the pyrohydrolysis-photometric method, the developed new method showed clear advantages regarding sensitivity and specificity. The time requirement for one sample analysis was strongly shortened from several hours to only some minutes. - Highlights: • First time determination of fluorine in niobium oxide using the slurry sampling technique • Application of calcium fluoride molecular absorption in graphite tube with ZrC modification • Higher specificity, better sensitivity, and huge time saving compared with the classical method based on pyrohydrolysis • New method verified by successful participation in round robin test.

  14. Direct determination of fluorine in niobium oxide using slurry sampling electrothermal high-resolution continuum source molecular absorption spectrometry

    Huang, Mao Dong; Becker-Ross, Helmut; Okruss, Michael; Geisler, Sebastian; Florek, Stefan; Richter, Silke; Meckelburg, Angela

    Aiming for a round-robin test, a new method for the direct determination of fluorine in niobium oxide has been developed. It is based on the use of high-resolution molecular absorption spectra of calcium mono-fluoride (CaF) generated in the graphite tube, combined with the slurry sampling technique. The absorption measurement was performed at the 606.44 nm CaF rotational line. By using graphite tubes with zirconium carbide (ZrC) modified platform, the molecular absorption sensitivity of CaF has been improved by a factor of 20, and no additional chemical modifier was necessary. Generally, non-spectral interferences were observed in the presence of HCl, H2SO4, and H3PO4. For HCl, additional spectral interference occurred due to an overlap of the absorption spectra of CaF and CaCl. However, due to the absence of these mentioned substances in the current material, such interferences do not exist for this application. The characteristic mass found for the CaF 606.44 nm line was 0.1 ng; the limit of detection was 5 mg fluorine per kg solid sample (3σ criterion). The results obtained by the method were within the range of certified values. Comparing to the classical method such as the pyrohydrolysis-photometric method, the developed new method showed clear advantages regarding sensitivity and specificity. The time requirement for one sample analysis was strongly shortened from several hours to only some minutes.

  15. Organic, inorganic and total mercury determination in fish by chemical vapor generation with collection on a gold gauze and electrothermal atomic absorption spectrometry

    Duarte, Fabio Andrei; Bizzi, Cezar Augusto; Goldschmidt Antes, Fabiane; Dressler, Valderi Luiz [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil); Flores, Erico Marlon de Moraes [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil)], E-mail: flores@quimica.ufsm.br

    2009-06-15

    A method for organic, inorganic and total mercury determination in fish tissue has been developed using chemical vapor generation and collection of mercury vapor on a gold gauze inside a graphite tube and further atomization by electrothermal atomic absorption spectrometry. After drying and cryogenic grinding, potassium bromide and hydrochloric acid solution (1 mol L{sup - 1} KBr in 6 mol L{sup - 1} HCl) was added to the samples. After centrifugation, total mercury was determined in the supernatant. Organomercury compounds were selectively extracted from KBr solution using chloroform and the resultant solution was back extracted with 1% m/v L-cysteine. This solution was used for organic Hg determination. Inorganic Hg remaining in KBr solution was directly determined by chemical vapor generation electrothermal atomic absorption spectrometry. Mercury vapor generation from extracts was performed using 1 mol L{sup - 1} HCl and 2.5% m/v NaBH{sub 4} solutions and a batch chemical vapor generation system. Mercury vapor was collected on the gold gauze heated resistively at 80 deg. C and the atomization temperature was set at 650 deg. C. The selectivity of extraction was evaluated using liquid chromatography coupled to chemical vapor generation and determination by inductively coupled plasma mass spectrometry. The proposed method was applied for mercury analysis in shark, croaker and tuna fish tissues. Certified reference materials were used to check accuracy and the agreement was better than 95%. The characteristic mass was 60 pg and method limits of detection were 5, 1 and 1 ng g{sup - 1} for organic, inorganic and total mercury, respectively. With the proposed method it was possible to analyze up to 2, 2 and 6 samples per hour for organic, inorganic and total Hg determination, respectively.

  16. Mesoporous Silica Nanoparticles as an Adsorbent for Preconcentration and Determination of Trace Amount of Nickel in Environmental Samples by Atom Trap Flame Atomic Absorption Spectrometry

    Shirkhanloo, H.; Falahnejad, M.; Zavvar Mousavi, H.

    2016-01-01

    A rapid enrichment method based on solid-phase extraction (SPE) has been established for preconcentration and separation of trace Ni(II) ions in water samples prior to their determination by atom trap flame atomic absorption spectrometry. A column filled with bulky NH2-UVM7 was used as the novel adsorbent. Under optimal conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were 3-92 μg/L, 0.8 μg/L, and 100, respectively. The validity of the method was checked by the standard reference material.

  17. Influence of soil composition in the determination of chromium by atomic absorption spectrometry with flame air / acetylene

    The Air-acetylene Flame Atomic Absorption determination of chromium is a complex task, being strongly influenced by sample composition and instrumental conditions. The objective of this work was to study the influence of Al, Ca, Fe, K, Mg, and Na on the absorption of chromium in the air-acetylene flame, both separately and combined in solution, when acetylene flow and burner height vary. Dissolutions of the mixtures simulated the composition of four soils from the Quibu River Basin in Havana, Cuba. Chromium absorption first increased and then decreased with increment of acetylene flow for shorter burner heights (∼ 2-4 mm); while a continuous increase was observed for larger heights (> 4 mm). This behavior was the same in the presence and absence of interfering chemical element, mentioned above. On the other hand, the dependence of the magnitude of the interference with acetylene flow and burner height was complex and dependent on the interfering element, particularly at larger heights where the behavior of Al was remarkably different. The interference of the four mixtures of Al, Ca, K, Fe, Mg and Na decreased in comparison to individual interfering effects and was less dependent on acetylene flow and burner height. Finally, a significant reduction of interference on chromium determination in soil samples was achieved by an adequate selection of acetylene flow and burner height

  18. Improvements in cobalt determination by thermospray flame furnace atomic absorption spectrometry using an on-line derivatization strategy.

    Matos, Geraldo Domingues; Arruda, Marco Aurélio Zezzi

    2008-07-15

    An on-line derivatization strategy was developed for improving cobalt sensitivity using thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) as the analytical technique. This strategy involves the generation of a volatile cobalt compound, providing better sample vaporization efficiency. The effect of sodium diethyldithiocarbamate (DDTC) as complexing agent on the integrated absorbance signal was evaluated. Parameters including the pH of complex formation, complex concentration and volume, sample volume, flame gas composition and tube atomization configuration were optimized. A wide linear range (from 23 microg L(-1) to 3 mg L(-1); r(2)=0.9786) was obtained, with the best one (r(2)=0.9992) attained from 23 to 400 microg L(-1) with a sample throughput of 30 h(-1). The improvement in the detection power was 17-fold when compared to FAAS, which provides 7 microg L(-1) as the limit of detection when considered TS-FF-AAS technique. A relative standard deviation (n=10) of 4% for a cobalt solution containing 50 microg L(-1) was attained, and the accuracy of the procedure was evaluated through certified reference materials (IAEA-SL-1, lake sediment; and ISS-MURST-A1, Antarctic marine sediment). Good agreement between the results at the 95% confidence level was observed. PMID:18585309

  19. Cloud Point Extraction Using Tergitol TMN-6 of Gold(III)in Real Samples by Flame Atomic Absorption Spectrometry Determination

    A simple, safe and rapid method on the basis of cloud point extraction (CPE) with tergitol TMN-6 had been used for the preconcentration and extraction of gold(Au) ion in selenium reduction solution sample prior to flame atomic absorption spectrometry (FAAS).Pyrrolidine dithio formic acid salt (PDFAS) which was regarded as a selective complexing agent could formed stable Au-complex with Au ion, and Au-complex could be extracted by TMN-6 at a short time. Some influencing factors such as sample pH, concentration of TMN-6, concentration of PDFAS and the effect of foreign ions were further researched .Under the optimum conditions, the limit of detection (LOD) was 1.3 meu g L/sup -1/, the calibration graph was linear in the range of 0-500 meu g/L and the relative standard deviation (RSD%) was 2.0%(n=8). The CPE method had been shown to be a useful and effective methodology for the separation of Au, with a preconcentration factor of 30. The recoveries of the spiked Au(?) ions were got in the range 95-103%. (author)

  20. Ionic liquid ultrasound assisted dispersive liquid-liquid microextraction method for preconcentration of trace amounts of rhodium prior to flame atomic absorption spectrometry determination

    Molaakbari, Elaheh [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Young Research Society, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Mostafavi, Ali, E-mail: mostafavi.ali@gmail.com [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Afzali, Daryoush [Environment and Nanochemistry Department, Research Institute of Environmental Science, International Center for Science, High Technology and Environmental Science, Kerman (Iran, Islamic Republic of); Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

    2011-01-30

    In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid-liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300 {mu}L ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0-500.0 ng mL{sup -1}, the detection limit was 0.37 ng mL{sup -1} (3S{sub b}/m, n = 7) and the relative standard deviation was {+-}1.63% (n = 7, C = 200 ng mL{sup -1}). The results show that ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption.

  1. Combination of cloud point extraction and flame atomic absorption spectrometry for preconcentration and determination of nickel and manganese ions in water and food samples

    A simple, rapid, inexpensive, and nonpolluting cloud point extraction (CPE) technique has been improved for the preconcentration and determination of nickel and manganese. After complexation with p-nitrophenylazoresorcinol (Magneson I), the analytes could be competitively extracted in a surfactant octylphenoxy polyethoxyethanol (Triton X-114), prior to determination by flame atomic absorption spectrometry (FAAS). The effects of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and time on CPE were studied. Under the optimum conditions, preconcentration of a 25 mL sample solution permitted the detection of 2.7 ng mL-1 Ni2+ and 2.9 ng mL-1 Mn2+ with enrichment factors of 17 and 19 for Ni2+ and Mn2+, respectively. The developed method was applied to the determination of trace nickel and manganese in water and food samples with satisfactory results.

  2. Dispersive liquid-liquid microextraction (DLLME combined with graphite furnace atomic absorption spectrometry (GFAAS for determination of trace Cu and Zn in water Samples

    Ghorbani A.

    2014-07-01

    Full Text Available Dispersive liquid-liquid microextraction (DLLME combined with graphite furnace atomic absorption spectrometry (GFAAS was proposed for the determination of trace amounts of Copper and Zinc ions using 8-hydroxyquinoline (8-HQ as chelating agent. Several factors influencing the microextraction efficiency of Cu and Zn and their subsequent determinations, such as pH, extraction and disperser solvent type and their volume, concentration of the chelating agent and extraction time were studied, and the optimized experimental conditions were established. After extraction, the enrichment factors were 25 and 26 for Cu and Zn, respectively. The detection limits of the method were 0.025 and 0.0033 μg/L for Cu and Zn, and the relative standard deviations (R.S.D for five determinations of 1 ng/ml Cu and Zn were 8.51% and 7.41%, respectively.

  3. Determination of yttrium and rare-earth elements in rocks by graphite-furnace atomic-absorption spectrometry.

    Gupta, J G

    1981-01-01

    With use of synthetic solutions and several international standard reference materials a method has been developed for determining traces of Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in rocks by electrothermal atomization in a pyrolytically-coated graphite furnace. Depending on the element, the sensitivity is of the order of 10(-9)-10(-12) g at 2500 degrees . To avoid matrix interferences the lanthanides are separated from the common elements by co-precipitation with calcium and iron as carriers. The data for Canadian reference rock SY-2 (syenite), U.S.G.S. reference rocks W-2 (diabase), DNC-1 (diabase) and BIR-1 (basalt), and South African reference rock NIM-18/69 (carbonatite) obtained by graphite-furnace atomization are compared with the values obtained by flame atomic-absorption. The results are in good agreement with literature values. PMID:18962852

  4. DIRECT DETERMINATION OF GOLD IN SUSPENSIONS OF ROCK AND ORE REFERENCE MATERIALS USING ELECTROTHERMAL HIGH RESOLUTION ATOMIC ABSORPTION SPECTROMETRY

    Zakharov, Y. А.; Irisov, D. S.; Okunev, R. V.; Musin, R. Kh.; Haibullin, R. R.

    2014-01-01

    High resolution continuum source atomic absorption spectrometer ContrAA-700 with graphite furnace is used for direct gold determination in rocks and ores on the level 10-6-10-3 % mas. Russian standard reference materials of gold containing ore СЗР-4 (2.13 ± 0.05 g/ton), black slates of Sykhoy Log СЛг-1 (2.50 ± 0.03 g/ton) and СЧС-1 (0.10 ± 0.02 g/ton) in mass 1 mg was inserted into the furnace in the suspension form prepared on the mix of concentrated HNO3 and HCl (1:3) with following sevenfo...

  5. Determination of lead, cadmium and mercury in blood for assessment of environmental exposure: A comparison between inductively coupled plasma-mass spectrometry and atomic absorption spectrometry

    A biomonitoring method for the determination of Pb, Cd, and Hg at background levels in whole blood by inductively coupled plasma-mass spectrometry is described. While this method was optimized for assessing Pb, Cd and Hg at environmental levels, it also proved suitable for assessing concentrations associated with occupational exposure. The method requires as little as 200 μl of blood that is diluted 1 + 49 for direct analysis in the inductively coupled plasma-mass spectrometer. Method performance is compared to well-established AAS methods. Initial method validation was accomplished using National Institute of Standards and Technology (NIST) Standard Reference Material 966, Toxic Metals in Bovine Blood. Method detection limits (3s) are 0.05 μg dl-1 for Pb, 0.09 μg l-1 for Cd; and 0.17 μg l-1 for Hg. Repeatability ranged from 1.4% to 2.8% for Pb; 3% to 10% for Cd; and 2.6% to 8.8% for Hg. In contrast, AAS method detection limits were 1 μg dl-1, 0.54 μg l-1, and 0.6 μg l-1, for Pb, Cd, and Hg, respectively. Further performance assessments were conducted over a 2-year period via participation in four international External Quality Assessment Schemes (EQAS) operated specifically for toxic metals in blood. This includes schemes operated by (a) the New York State Department of Health's Wadsworth Center, Albany, NY, USA (b) L'Institut National de Sante Publique du Quebec, Centre de Toxicologie du Quebec, Canada (c) Friedrich-Alexander University, Erlangen, Germany, and (d) the University of Surrey, Guildford, UK Trace Elements scheme. The EQAS data reflect analytical performance for blind samples analyzed independently by both inductively coupled plasma-mass spectrometry and AAS methods

  6. Solid sampling determination of total fluorine in baby food samples by high-resolution continuum source graphite furnace molecular absorption spectrometry.

    Ozbek, Nil; Akman, Suleyman

    2016-11-15

    This study describes the applicability of solid sampling technique for the determination of fluorine in various baby foods via molecular absorption of calcium monofluoride generated in a graphite furnace of high-resolution continuum source atomic absorption spectrometry. Fluorine was determined at CaF wavelength, 606.440nm in a graphite tube applying a pyrolysis temperature of 1000°C and a molecule forming temperature of 2200°C. The limit of detection and characteristic mass of the method were 0.20ng and 0.17ng of fluorine, respectively. The fluorine concentrations determined in standard reference sample (bush branches and leaves) were in good agreement with the certified values. By applying the optimized parameters, the concentration of fluorine in various baby foods were determined. The fluorine concentrations were ranged from determined. PMID:27283621

  7. Dithizone chloroform single drop microextraction system combined with electrothermal atomic absorption spectrometry using Ir as permanent modifier for the determination of Cd in water and biological samples

    Fan, Zhefeng; Zhou, Wei

    2006-07-01

    A simple and sensitive method using dithizone-chloroform single drop microextraction has been developed for separation and preconcentration of trace Cd prior to its determination by electrothermal atomic absorption spectrometry with Ir as permanent modifier. Parameters, such as pyrolysis and atomization temperature, solvent type, pH, dithizone concentration, extraction time, organic drop volume, stirring rate and sample volume were investigated. Under the optimized conditions, a detection limit (3 σ) of 0.7 ng/l and enrichment factor of 65 were achieved. The relative standard deviation was 7.4% ( c = 0.2 μg/l, n = 5). The developed method has been applied to the determination of trace Cd in water samples and biological reference materials with satisfactory results.

  8. Dithizone-chloroform single drop microextraction system combined with electrothermal atomic absorption spectrometry using Ir as permanent modifier for the determination of Cd in water and biological samples

    Fan Zhefeng [Department of Chemistry, Shanxi Normal University, Linfen 041004 (China)]. E-mail: zhefengfan@163.com; Zhou Wei [Department of Chemistry, Shanxi Normal University, Linfen 041004 (China)

    2006-07-15

    A simple and sensitive method using dithizone-chloroform single drop microextraction has been developed for separation and preconcentration of trace Cd prior to its determination by electrothermal atomic absorption spectrometry with Ir as permanent modifier. Parameters, such as pyrolysis and atomization temperature, solvent type, pH, dithizone concentration, extraction time, organic drop volume, stirring rate and sample volume were investigated. Under the optimized conditions, a detection limit (3{sigma}) of 0.7 ng/l and enrichment factor of 65 were achieved. The relative standard deviation was 7.4% (c = 0.2 {mu}g/l, n = 5). The developed method has been applied to the determination of trace Cd in water samples and biological reference materials with satisfactory results.

  9. Evaluation of cadmium in greenhouse soils and agricultural products of Jiroft (Iran) using microwave digestion prior to atomic absorption spectrometry determination.

    Afzali, Daryoush; Fathirad, Fariba; Afzali, Zahra; Majdzadeh-Kermani, Seyed Mohammad Javad

    2015-03-01

    This study determines total levels of potentially toxic trace element, Cd (II) in Jiroft (Kerman, Iran) greenhouse soil and agricultural products that are grown in these greenhouses (tomatoes and cucumbers), and the comparison with soil outside of greenhouse using microwave digestion prior to flame atomic absorption spectrometry determination. The results show that the cadmium concentration in greenhouse soil is 0.9-1.9 mg kg(-1) and out of greenhouse is 0.4-1.0 mg kg(-1). Also, cadmium concentration range in tomatoes and cucumbers is about 0.07-0.40 mg kg(-1). The obtained results show that the concentration of this metal in greenhouse soil is higher than outside soil samples and is below the safe limit. PMID:25697307

  10. Experimental design applied to the development of a copper direct determination method in gasoline samples by graphite furnace atomic absorption spectrometry

    Sousa, Janyeid Karla Castro; Marques, Aldalea Lopes Brandes [Programa de Pos Graduacao em Quimica, Av. dos Portugueses S/N, Campus Bacanga, Universidade Federal do Maranhao, Sao Luis, MA (Brazil); Dantas, Allan Nilson de Sousa; Lopes, Gisele Simone [Departamento de Quimica Analitica e Fisico-Quimica, bloco 939, Campus do Pici, Universidade Federal do Ceara, 60.000-000, Fortaleza, CE (Brazil)

    2008-11-15

    The aim of this work was to develop an experimental design to optimize the direct determination of copper in gasoline by graphite furnace atomic absorption spectrometry. The optimization of the process was carried out firstly by evaluating the variables in the procedure (pyrolysis time and temperature, atomization temperature and sample volume) using a factorial design (2{sup 4}). The response surface was constructed and it presented pyrolysis optimal temperature on 800 C, sample volume of 30 {mu}L using the atomization temperature of 2500 C. The amount of copper in the gasoline samples from Sao Luis City (Brazil) varied from 3.65 to 16.21 {mu}g L{sup -} {sup 1}, with 0.65 and 1.9 {mu}g L{sup -} {sup 1} as detection limit and quantification limit, respectively. Accuracy was evaluated by a comparative procedure and the results proved the viability of copper direct determination in fuel samples. (author)

  11. Determination of Iron in Layered Crystal Sodium Disilicate and Sodium Silicate by Flame Atomic Absorption Spectrometry with Boric Acid as a Matrix Modifier

    Zhi Hua WANG; Min CAI; Shu Jun WANG

    2006-01-01

    The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry (FAAS) were investigated. It was found that boric acid as a matrix modifier obviously eliminated silicate interference. Under the optimum operating conditions, the determination results of iron in layered crystal sodium disilicate and sodium silicate samples by FAAS were satisfactory. The linear range of calibration curve is 0-10.5 μg.mL-1, the relative standard deviation of method is 1.2%-2.2%, the recovery of added iron is 96.0%-101%, the of iron of the standard curve method, standard addition calibration and colorimetry method was the same, but the first has the merits of rapid sample preparation, reduced contamination risks and fast analysis.

  12. Determination of lead in water resources by flame atomic absorption spectrometry after pre-concentration with ammonium pyrrolidinedithiocarbamate immobilized on surfactant-coated alumina

    SAYED MORTEZA TALEBI

    2007-06-01

    Full Text Available Arapid, simple, and sensitive procedure based on modified solid phase extraction was developed for the pre-concentration and determination of trace amount of lead in water resources. Lead was reacted with ammonium pyrrolidinedithiocarbamate (APDC to make a complex. The complex was then collected in a column packed with surfactant-coated alumina. The parameters affecting the collection efficiency and desorption rate of the lead complexes from the column were investigated and optimized. The collection efficiency of the lead complex on the adsorbent was excellent under the optimized conditions. The results obtained from the recovery test showed the capability and reliability of the method for the analysis of trace amounts of lead. The proposed pre-concentration procedure made it possible to apply conventional flame atomic absorption spectrometry (FAAS for the sensitive determination of trace amounts of lead in water resources.

  13. Solvent microextraction-flame atomic absorption spectrometry (SME-FAAS) for determination of ultratrace amounts of cadmium in meat and fish samples.

    Goudarzi, Nasser

    2009-02-11

    A simple, low cost and highly sensitive method based on solvent microextraction (SME) for separation/preconcentration and flame atomic absorption spectrometry (FAAS) was proposed for the determination of ultratrace amounts of cadmium in meat and fish samples. The analytical procedure involved the formation of a hydrophobic complex by mixing the analyte solution with an ammonium pyrrolidinedithiocarbamate (APDC) solution. In suitable conditions, the complex of cadmium-APDC entered the micro organic phase, and thus, separation of the analyte from the matrix was achieved. Under optimal chemical and instrumental conditions, a detection limit (3 sigma) of 0.8 ng L(-1) and an enrichment factor of 93 were achieved. The relative standard deviation for the method was found to be 2.2% for Cd. The interference effects of some anions and cations were also investigated. The developed method has been applied to the determination of trace Cd in meat and fish samples. PMID:19138082

  14. Cu determination in crude oil distillation products by atomic absorption and inductively coupled plasma mass spectrometry after analyte transfer to aqueous solution

    Cu was determined in a wide range of petroleum products from crude oil distillation using flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICP-MS). Different procedures of sample preparation were evaluated: (i) mineralization with sulfuric acid in an open system (ii) mineralization in a closed microwave system (iii) combustion in hydrogen-oxygen flame in the Wickbold's apparatus (iv) matrix evaporation followed by acid dissolution, and (v) acidic extraction. All the above procedures led to the transfer of the analyte into an aqueous solution for the analytical measurement step. It was found that application of FAAS was limited to the analysis of the heaviest petroleum products of high Cu content. In ICP-MS, the use of internal reference method (with Rh or In as internal reference element) was required to eliminate the matrix effects in the analysis of extracts and the concentrated solutions of mineralized heavy petroleum products. The detection limits (in original samples) were equal to, respectively, 10, 86, 3.3, 0.9 and 0.4 ng g-1 in procedures i-v with ETAAS detection and 10, 78, 1.1 and 0.5 ng g-1 in procedures i-iii and v with ICP-MS detection. The procedures recommended here were validated by recovery experiments, certified reference materials analysis and comparison of results, obtained for a given sample, in different ways. The Cu content in the analyzed samples was: 50-110 ng g-1 in crude oil, -1 in gasoline, -1 in atmospheric oil, -1 in heavy vacuum oil and 140-300 ng g-1 in distillation residue

  15. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3σ), based on ten atomizations of an unexposed filter, was 40 ng g-1, corresponding to 0.12 ng m-3 in the air for a typical air volume of 1440 m3 collected within 24 h. The limit of quantification was 150 ng g-1, equivalent to 0.41 ng m-3 in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between -1 and 381 ± 24 ng g-1. These values correspond to a mercury concentration in the air between -3 and 1.47 ± 0.09 ng m-3. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

  16. Determination of trace elements in dolomite and gypsum by atomic absorption spectrometry: overcoming the matrix interference by flotation separation

    Stafilov, Trajče; Zendelovska, Dragica; Pavlovska, Gorica; Čundeva, Katarina

    2002-05-01

    The interferences of Ca and Mg as matrix elements in dolomite and gypsum on Ag, Cd, Cr, Mn, Tl and Zn absorbances during their electrothermal atomic absorption spectrometric (ETAAS) determination are investigated. The results reveal that Ca and Mg do not interfere on Zn and Mn, tend to decrease absorbances of Ag, Cd and Cr, while Tl suffers the most significant influence. A flotation separation method is proposed to eliminate matrix interferences. Hydrated iron(III) oxide, Fe 2O 3· xH 2O, and iron(III) hexamethylenedithiocarbamate, Fe(HMDTC) 3, are applied as flotation collectors. The influence of hydrophobic dithiocarbamate anion, HMDTC, on flotation recoveries of each analyte is studied. The most suitable concentrations of dolomite and gypsum solutions for flotation are determined. To avoid flotation suppression due to the reaction of Ca 2+ and Mg 2+ with surfactant ions, a fit foaming agent was selected. The elements present in dolomite and gypsum as traces have been analyzed by ETAAS. Their ETAAS limits of detection following flotation are found to be 0.021 μg·g -1 for Ag, 0.019 μg·g -1 for Cd, 0.014 μg·g -1 for Cr and 0.11 μg·g -1 for Tl. The determination of Mn and Zn can be performed by flame AAS (FAAS). The limit of detection for Mn is 1.5 μg·g -1, while for Zn 0.8 μg·g -1.

  17. Determination of halogens via molecules in the air-acetylene flame using high-resolution continuum source absorption spectrometry, Part II: Chlorine

    As continuation of the work on fluorine, the second part of the studies of halogens in the air-acetylene flame attends to the determination of chlorine using high-resolution continuum source absorption spectrometry and molecular absorption. In case of chlorine, the diatomic InCl molecule proved to be a suitable species. For an excess of In in the flame, chlorine is converted to InCl which produces a distinctive band head at 267.24 nm that could be evaluated analytically. The influence of concentrated inorganic acids and metallic matrices on the absorption at this band head was tested. In all cases the signal proved to be unaffected, i.e., no spectral interferences were observed. However, serious chemical interferences were found in the presence of sulfuric and phosphoric acids, which could be partially eliminated by adding Ca in the form of nitrate. Moreover, nitric and hydrofluoric acids as well as Cu and Ga matrices also produced significant chemical interferences. Therefore, the method of standard additions should be used for calibration purposes. Concerning the limit of detection, a value of 3 mg L-1 was achieved for a measurement time of 5 s in the presence of 10,000 mg L-1 In. The calibration curve was linear up to a chlorine concentration of 1800 mg L-1. Three certified reference materials (BCR 151, HISS-1, and PACS-2) were analyzed to test the performance of the new method, yielding good precision and accuracy

  18. Determination of ultra trace amounts of bismuth in biological and water samples by electrothermal atomic absorption spectrometry (ET-AAS) after cloud point extraction

    Shemirani, Farzaneh; Baghdadi, Majid; Ramezani, Majid; Jamali, Mohammad Reza

    2005-04-04

    A new approach for a cloud point extraction electrothermal atomic absorption spectrometric method was used for determining bismuth. The aqueous analyte was acidified with sulfuric acid (pH 3.0-3.5). Triton X-114 was added as a surfactant and dithizone was used as a complexing agent. After phase separation at 50 deg. C based on the cloud point separation of the mixture, the surfactant-rich phase was diluted using tetrahydrofuran (THF). Twenty microliters of the enriched solution and 10 {mu}l of 0.1% (w/v) Pd(NO{sub 3}){sub 2} as chemical modifier were dispersed into the graphite tube and the analyte determined by electrothermal atomic absorption spectrometry. After optimizing extraction conditions and instrumental parameters, a preconcentration factor of 196 was obtained for a sample of only 10 ml. The detection limit was 0.02 ng ml{sup -1} and the analytical curve was linear for the concentration range of 0.04-0.60 ng ml{sup -1}. Relative standard deviations were <5%. The method was successfully applied for the extraction and determination of bismuth in tap water and biological samples (urine and hair)

  19. Strontium mono-chloride — A new molecule for the determination of chlorine using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Pereira, Éderson R. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Welz, Bernhard, E-mail: w.bernardo@terra.com.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Lopez, Alfredo H.D.; Gois, Jefferson S. de; Caramori, Giovanni F. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Borges, Daniel L.G.; Carasek, Eduardo [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2014-12-01

    A new method has been developed for the determination of chlorine in biological reference materials using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) of the strontium mono-chloride (SrCl) molecule and direct solid sample analysis. The use of the SrCl molecule for high-temperature MAS was not described up to now in the literature. Preliminary time-dependent density functional theory calculations of the SrCl structure were carried out in order to obtain reasonable estimates of the absorption spectrum of the target molecule. The calculations, which were carried out at BHandHLyp/def2-QZVP level of theory, proved a very accurate and inexpensive way to get information about the spectrum of the SrCl molecule, which enabled us to perform the Cl determination with good sensitivity and specificity. The molecular absorption of the SrCl molecule has been measured using the wavelength at 635.862 nm, and zirconium and palladium have been evaluated as the chemical modifiers in order to increase the sensitivity of the gaseous SrCl molecule generated in the graphite furnace. The pyrolysis and vaporization temperatures were 600 °C and 2300 °C, respectively. Accuracy and precision of the method have been evaluated using biological certified reference materials of both animal and plant origins, showing good agreement with the informed and certified values. Limit of detection and characteristic mass were 1.0 and 2.2 ng, respectively. The results found using HR-CS GF MAS were in agreement (95% confidence level) compared to those obtained by electrothermal vaporization-inductively coupled plasma mass spectrometry. - Highlights: • The spectrum of the SrCl molecule was calculated on a theoretical basis and found very close to the predicted wavelength. • It is the first time that the spectrum of the SrCl molecule is described and used analytically for the determination of Cl. • No spectral interferences were observed as the

  20. Strontium mono-chloride — A new molecule for the determination of chlorine using high-resolution graphite furnace molecular absorption spectrometry and direct solid sample analysis

    A new method has been developed for the determination of chlorine in biological reference materials using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) of the strontium mono-chloride (SrCl) molecule and direct solid sample analysis. The use of the SrCl molecule for high-temperature MAS was not described up to now in the literature. Preliminary time-dependent density functional theory calculations of the SrCl structure were carried out in order to obtain reasonable estimates of the absorption spectrum of the target molecule. The calculations, which were carried out at BHandHLyp/def2-QZVP level of theory, proved a very accurate and inexpensive way to get information about the spectrum of the SrCl molecule, which enabled us to perform the Cl determination with good sensitivity and specificity. The molecular absorption of the SrCl molecule has been measured using the wavelength at 635.862 nm, and zirconium and palladium have been evaluated as the chemical modifiers in order to increase the sensitivity of the gaseous SrCl molecule generated in the graphite furnace. The pyrolysis and vaporization temperatures were 600 °C and 2300 °C, respectively. Accuracy and precision of the method have been evaluated using biological certified reference materials of both animal and plant origins, showing good agreement with the informed and certified values. Limit of detection and characteristic mass were 1.0 and 2.2 ng, respectively. The results found using HR-CS GF MAS were in agreement (95% confidence level) compared to those obtained by electrothermal vaporization-inductively coupled plasma mass spectrometry. - Highlights: • The spectrum of the SrCl molecule was calculated on a theoretical basis and found very close to the predicted wavelength. • It is the first time that the spectrum of the SrCl molecule is described and used analytically for the determination of Cl. • No spectral interferences were observed as the

  1. A fast and accurate microwave-assisted digestion method for arsenic determination in complex mining residues by flame atomic absorption spectrometry

    A fast and accurate microwave-assisted digestion method for arsenic determination by flame atomic absorption spectrometry (FAAS) in typical, complex residues from gold mining is presented. Three digestion methods were evaluated: an open vessel digestion using a mixture of HCl:HNO3:HF acids (Method A) and two microwave digestion methods using a mixture of HCl:H2O2:HNO3 in high (Method B) and medium-pressure (Method C) vessels. The matrix effect was also investigated. Arsenic concentration from external and standard addition calibration curves (at a 95% confidence level) were statistically equal (p-value = 0.122) using microwave digestion in high-pressure vessel. The results from the open vessel digestion were statistically different (p-value = 0.007) whereas in the microwave digestion in medium-pressure vessel (Method C) the dissolution of the samples was incomplete.

  2. A fast and accurate microwave-assisted digestion method for arsenic determination in complex mining residues by flame atomic absorption spectrometry.

    Pantuzzo, Fernando L; Silva, Julio César J; Ciminelli, Virginia S T

    2009-09-15

    A fast and accurate microwave-assisted digestion method for arsenic determination by flame atomic absorption spectrometry (FAAS) in typical, complex residues from gold mining is presented. Three digestion methods were evaluated: an open vessel digestion using a mixture of HCl:HNO(3):HF acids (Method A) and two microwave digestion methods using a mixture of HCl:H(2)O(2):HNO(3) in high (Method B) and medium-pressure (Method C) vessels. The matrix effect was also investigated. Arsenic concentration from external and standard addition calibration curves (at a 95% confidence level) were statistically equal (p-value=0.122) using microwave digestion in high-pressure vessel. The results from the open vessel digestion were statistically different (p-value=0.007) whereas in the microwave digestion in medium-pressure vessel (Method C) the dissolution of the samples was incomplete. PMID:19345010

  3. A fast and accurate microwave-assisted digestion method for arsenic determination in complex mining residues by flame atomic absorption spectrometry

    Pantuzzo, Fernando L.; Silva, Julio Cesar J. [Dept. of Metallurgical and Materials Engineering, Universidade Federal de Minas Gerais (UFMG), Rua Espirito Santo, 35/206, 30160-030 Belo Horizonte, Minas Gerais (Brazil); Ciminelli, Virginia S.T., E-mail: ciminelli@demet.ufmg.br [Dept. of Metallurgical and Materials Engineering, Universidade Federal de Minas Gerais (UFMG), Rua Espirito Santo, 35/206, 30160-030 Belo Horizonte, Minas Gerais (Brazil)

    2009-09-15

    A fast and accurate microwave-assisted digestion method for arsenic determination by flame atomic absorption spectrometry (FAAS) in typical, complex residues from gold mining is presented. Three digestion methods were evaluated: an open vessel digestion using a mixture of HCl:HNO{sub 3}:HF acids (Method A) and two microwave digestion methods using a mixture of HCl:H{sub 2}O{sub 2}:HNO{sub 3} in high (Method B) and medium-pressure (Method C) vessels. The matrix effect was also investigated. Arsenic concentration from external and standard addition calibration curves (at a 95% confidence level) were statistically equal (p-value = 0.122) using microwave digestion in high-pressure vessel. The results from the open vessel digestion were statistically different (p-value = 0.007) whereas in the microwave digestion in medium-pressure vessel (Method C) the dissolution of the samples was incomplete.

  4. Direct determination of Cr and Cu in urine samples by electrothermal atomic absorption spectrometry using ruthenium as permanent modifier (R1)

    Lelis, Katia Linces Alves; Rocha, Clelia Aparecida [Instituto de Patologia Clinica Hermes Pardini, 30140-070 Belo Horizonte, MG (Brazil); Magalhaes, Cristina Goncalves; Silva, Jose Bento Borba of [Departamento de Quimica, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG (Brazil)

    2002-12-01

    In this study Ru, deposited thermally on an integrated platform pyrolytic graphite tube, is proposed as a permanent modifier for the determination of Cu and Cr in urine samples by electrothermal atomic absorption spectrometry. The samples were diluted 1:1 with nitric acid (1% v/v). Pyrolysis and atomization temperatures for spiked urine samples were 1,100 C and 1,900 C respectively for Cu, and 1,400 C and 2,500 C respectively for Cr. For comparison purposes, the conventional modification with Pd+Mg was also studied. The sensitivity for Ru as permanent modifier was higher for the two analytes. The characteristic masses were 7.3 and 17.7 for Cr and Cu. The detection limits (3{sigma}) were 0.22 and 0.32 {mu}g/L, for Cr and Cu, respectively. Good agreement was obtained with certified urine samples for the two elements. (orig.)

  5. Preconcentration, speciation and determination of ultra trace amounts of mercury by modified octadecyl silica membrane disk/electron beam irradiation and cold vapor atomic absorption spectrometry

    Mercury (II) and methyl mercury cations at the Sub-ppb level were adsorbed quantitatively from aqueous solution onto an octadecyl-bonded silica membrane disk modified by 2-[(2-mercaptophyenylimino)methyl] phenol (MPMP). The trapped mercury was then eluted with 3 ml ethanol and Hg2+ ion was directly measured by cold vapor atomic absorption spectrometry, utilizing tin (II) chloride. Total mercury (Hgt) was determined after conversion of MeHg+ into Hg2+ ion by electron beam irradiation. A sample volume of 1500 ml resulted in a preconcentration factor of 500 and the precision for a sampling volume of 500 ml at a concentration of 2.5 μg l-1 (n = 7) was 3.1%. The limit of detection of the proposed method is 3.8 ng l-1. The method was successfully applied to analysis of water samples, and the accuracy was assessed via recovery experiment

  6. Application of High Resolution-Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS): determination of trace elements in tea and tisanes.

    Paz-Rodríguez, Beatriz; Domínguez-González, María Raquel; Aboal-Somoza, Manuel; Bermejo-Barrera, Pilar

    2015-03-01

    A new application of HR-CS FAAS (High Resolution-Continuum Source Flame Atomic Absorption Spectrometry) has been developed for the determination of several trace elements (Ca, Co, Cu, Fe, Mn, Ni, Na and Zn) in infusions made from tea, rooibos and tea with seaweed samples. The proposed methods are fast, inexpensive and show good performances: the mean analytical recovery was approximately 100%. The mean limit of detection was 29.4 μg/l, and the mean limit of quantification was 98.0 μg/l (both limits refer to the brewed samples). Due to the matrix effect observed, the standard addition method had to be applied. Preliminary classification (based on metal contents) using chemometric techniques such as PCA (Principal Component Analysis) and CA (Cluster Analysis), was successful for infusions made from rooibos and tea with seaweed, but inconclusive for black and green teas. PMID:25306375

  7. Method development for the determination of bromine in coal using high-resolution continuum source graphite furnace molecular absorption spectrometry and direct solid sample analysis

    Pereira, Éderson R.; Castilho, Ivan N.B. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Welz, Bernhard, E-mail: w.bernardo@terra.com.br [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Gois, Jefferson S. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Borges, Daniel L.G. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Carasek, Eduardo [Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2014-06-01

    This work reports a simple approach for Br determination in coal using direct solid sample analysis in a graphite tube furnace and high-resolution continuum source molecular absorption spectrometry. The molecular absorbance of the calcium mono-bromide (CaBr) molecule has been measured using the rotational line at 625.315 nm. Different chemical modifiers (zirconium, ruthenium, palladium and a mixture of palladium and magnesium nitrates) have been evaluated in order to increase the sensitivity of the CaBr absorption, and Zr showed the best overall performance. The pyrolysis and vaporization temperatures were 800 °C and 2200 °C, respectively. Accuracy and precision of the method have been evaluated using certified coal reference materials (BCR 181, BCR 182, NIST 1630a, and NIST 1632b) with good agreement (between 98 and 103%) with the informed values for Br. The detection limit was around 4 ng Br, which corresponds to about 1.5 μg g{sup −1} Br in coal, based on a sample mass of 3 mg. In addition, the results were in agreement with those obtained using electrothermal vaporization inductively coupled plasma mass spectrometry, based on a Student t-test at a 95% confidence level. A mechanism for the formation of the CaBr molecule is proposed, which might be considered for other diatomic molecules as well. - Highlights: • Bromine has been determined in coal using direct solid sample analysis. • Calibration has been carried out against aqueous standard solutions. • The coal samples and the molecule-forming reagent have been separated in order to avoid interferences. • The results make possible to draw conclusions about the mechanisms of molecule formation.

  8. Method development for the determination of bromine in coal using high-resolution continuum source graphite furnace molecular absorption spectrometry and direct solid sample analysis

    This work reports a simple approach for Br determination in coal using direct solid sample analysis in a graphite tube furnace and high-resolution continuum source molecular absorption spectrometry. The molecular absorbance of the calcium mono-bromide (CaBr) molecule has been measured using the rotational line at 625.315 nm. Different chemical modifiers (zirconium, ruthenium, palladium and a mixture of palladium and magnesium nitrates) have been evaluated in order to increase the sensitivity of the CaBr absorption, and Zr showed the best overall performance. The pyrolysis and vaporization temperatures were 800 °C and 2200 °C, respectively. Accuracy and precision of the method have been evaluated using certified coal reference materials (BCR 181, BCR 182, NIST 1630a, and NIST 1632b) with good agreement (between 98 and 103%) with the informed values for Br. The detection limit was around 4 ng Br, which corresponds to about 1.5 μg g−1 Br in coal, based on a sample mass of 3 mg. In addition, the results were in agreement with those obtained using electrothermal vaporization inductively coupled plasma mass spectrometry, based on a Student t-test at a 95% confidence level. A mechanism for the formation of the CaBr molecule is proposed, which might be considered for other diatomic molecules as well. - Highlights: • Bromine has been determined in coal using direct solid sample analysis. • Calibration has been carried out against aqueous standard solutions. • The coal samples and the molecule-forming reagent have been separated in order to avoid interferences. • The results make possible to draw conclusions about the mechanisms of molecule formation

  9. Use of High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS) for Sequential Multi-Element Determination of Metals in Seawater and Wastewater Samples

    Peña-Vázquez, E.; Barciela-Alonso, M. C.; Pita-Calvo, C.; Domínguez-González, R.; Bermejo-Barrera, P.

    2015-09-01

    The objective of this work is to develop a method for the determination of metals in saline matrices using high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Module SFS 6 for sample injection was used in the manual mode, and flame operating conditions were selected. The main absorption lines were used for all the elements, and the number of selected analytical pixels were 5 (CP±2) for Cd, Cu, Fe, Ni, Pb and Zn, and 3 pixels for Mn (CP±1). Samples were acidified (0.5% (v/v) nitric acid), and the standard addition method was used for the sequential determination of the analytes in diluted samples (1:2). The method showed good precision (RSD(%) < 4%, except for Pb (6.5%)) and good recoveries. Accuracy was checked after the analysis of an SPS-WW2 wastewater reference material diluted with synthetic seawater (dilution 1:2), showing a good agreement between certified and experimental results.

  10. Multiwalled carbon nanotubes as a sorbent material for the solid phase extraction of lead from urine and subsequent determination by electrothermal atomic absorption spectrometry

    Peña Crecente, Rosa M.; Lovera, Carlha Gutiérrez; García, Julia Barciela; Méndez, Jennifer Álvarez; Martín, Sagrario García; Latorre, Carlos Herrero, E-mail: carlos.herrero@usc.es

    2014-11-01

    The determination of lead in urine is a way of monitoring the chemical exposure to this metal. In the present paper, a new method for the Pb determination by electrothermal atomic absorption spectrometry (ETAAS) in urine at low levels has been developed. Lead was separated from the undesirable urine matrix by means of a solid phase extraction (SPE) procedure. Oxidized multiwalled carbon nanotubes have been used as a sorbent material. Lead from urine was retained at pH 4.0 and was quantitatively eluted using a 0.7 M nitric acid solution and was subsequently measured by ETAAS. The effects of parameters that influence the adsorption–elution process (such as pH, eluent volume and concentration, sampling and elution flow rates) and the atomic spectrometry conditions have been studied by means of different factorial design strategies. Under the optimized conditions, the detection and quantification limits obtained were 0.08 and 0.26 μg Pb L{sup −1}, respectively. The results demonstrate the absence of a urine matrix effect and this is the consequence of the SPE process carried out. Therefore, the developed method is useful for the analysis of Pb at low levels in real samples without the influence of other urine components. The proposed method was applied to the determination of lead in urine samples of unexposed healthy people and satisfactory results were obtained (in the range 3.64–22.9 μg Pb L{sup −1}). - Highlights: • Lead determination in urine using a solid phase extraction procedure followed by ETAAS • Carbon nanotubes as SPE adsorbent for Pb in urine • Matrix elimination for the Pb determination in urine by using SPE based on carbon nanotubes • The detection limit was 0.08 μg Pb L{sup −1}.

  11. Multiwalled carbon nanotubes as a sorbent material for the solid phase extraction of lead from urine and subsequent determination by electrothermal atomic absorption spectrometry

    The determination of lead in urine is a way of monitoring the chemical exposure to this metal. In the present paper, a new method for the Pb determination by electrothermal atomic absorption spectrometry (ETAAS) in urine at low levels has been developed. Lead was separated from the undesirable urine matrix by means of a solid phase extraction (SPE) procedure. Oxidized multiwalled carbon nanotubes have been used as a sorbent material. Lead from urine was retained at pH 4.0 and was quantitatively eluted using a 0.7 M nitric acid solution and was subsequently measured by ETAAS. The effects of parameters that influence the adsorption–elution process (such as pH, eluent volume and concentration, sampling and elution flow rates) and the atomic spectrometry conditions have been studied by means of different factorial design strategies. Under the optimized conditions, the detection and quantification limits obtained were 0.08 and 0.26 μg Pb L−1, respectively. The results demonstrate the absence of a urine matrix effect and this is the consequence of the SPE process carried out. Therefore, the developed method is useful for the analysis of Pb at low levels in real samples without the influence of other urine components. The proposed method was applied to the determination of lead in urine samples of unexposed healthy people and satisfactory results were obtained (in the range 3.64–22.9 μg Pb L−1). - Highlights: • Lead determination in urine using a solid phase extraction procedure followed by ETAAS • Carbon nanotubes as SPE adsorbent for Pb in urine • Matrix elimination for the Pb determination in urine by using SPE based on carbon nanotubes • The detection limit was 0.08 μg Pb L−1

  12. Feasibility of dispersive liquid–liquid microextraction for extraction and preconcentration of Cu and Fe in red and white wine and determination by flame atomic absorption spectrometry

    Seeger, Tassia S.; Rosa, Francisco C.; Bizzi, Cezar A.; Dressler, Valderi L.; Flores, Erico M.M.; Duarte, Fabio A., E-mail: fabioand@gmail.com

    2015-03-01

    A method for extraction and preconcentration of Cu and Fe in red and white wines using dispersive liquid–liquid microextraction (DLLME) and determination by flame atomic absorption spectrometry (F AAS) was developed. Extraction was performed using sodium diethyldithiocarbamate as chelating agent and a mixture of 40 μL of 1,2-dichlorobenzene (extraction solvent) and 900 μL of methanol (dispersive solvent). Some parameters that influencing the extraction efficiency such as pH (2 to 5), concentration of chelating agent (0 to 2%), effect of salt addition (0 to 10%), number of washing steps (1 to 4) and centrifugation time (0 to 15 min) were studied. Accuracy was evaluated after microwave-assisted digestion in closed vessels and analytes were determined by inductively coupled plasma optical emission spectrometry. Agreement with the proposed method ranged from 91 to 110 and from 89 to 113% for Cu and Fe, respectively. Calibration of F AAS instrument was performed using analyte addition method and limits of detection were 6.3 and 2.4 μg L{sup −1} for Cu and Fe, respectively. The proposed method was applied for the determination of Cu and Fe in five samples of red wine and three samples of white wine, with concentration ranging from 21 to 178 μg L{sup −1} and from 1.38 to 3.74 mg L{sup −1}, respectively. - Highlights: • Determination of Cu and Fe in wine using DLLME and F AAS • High preconcentration factors and low LODs were achieved. • Alternative method for the determination of Cu and Fe in wine for routine analysis.

  13. Feasibility of dispersive liquid–liquid microextraction for extraction and preconcentration of Cu and Fe in red and white wine and determination by flame atomic absorption spectrometry

    A method for extraction and preconcentration of Cu and Fe in red and white wines using dispersive liquid–liquid microextraction (DLLME) and determination by flame atomic absorption spectrometry (F AAS) was developed. Extraction was performed using sodium diethyldithiocarbamate as chelating agent and a mixture of 40 μL of 1,2-dichlorobenzene (extraction solvent) and 900 μL of methanol (dispersive solvent). Some parameters that influencing the extraction efficiency such as pH (2 to 5), concentration of chelating agent (0 to 2%), effect of salt addition (0 to 10%), number of washing steps (1 to 4) and centrifugation time (0 to 15 min) were studied. Accuracy was evaluated after microwave-assisted digestion in closed vessels and analytes were determined by inductively coupled plasma optical emission spectrometry. Agreement with the proposed method ranged from 91 to 110 and from 89 to 113% for Cu and Fe, respectively. Calibration of F AAS instrument was performed using analyte addition method and limits of detection were 6.3 and 2.4 μg L−1 for Cu and Fe, respectively. The proposed method was applied for the determination of Cu and Fe in five samples of red wine and three samples of white wine, with concentration ranging from 21 to 178 μg L−1 and from 1.38 to 3.74 mg L−1, respectively. - Highlights: • Determination of Cu and Fe in wine using DLLME and F AAS • High preconcentration factors and low LODs were achieved. • Alternative method for the determination of Cu and Fe in wine for routine analysis

  14. Determination of As(III) and As(V) by Flow Injection-Hydride Generation-Atomic Absorption Spectrometry via On-line Reduction of As(V) by KI

    Nielsen, Steffen; Hansen, Elo Harald

    1997-01-01

    A volume-based flow injection (FI) procedure is described for the determination and speciation of trace inorganic arsenic, As(III) and As(V), via hydride generation-atomic absorption spectrometry (HG-AAS) of As(III). The determination of total arsenic is obtained by on-line reduction of As(V) to As...

  15. Speciation and determination of ultra trace amounts of chromium by solidified floating organic drop microextraction (SFODME) and graphite furnace atomic absorption spectrometry

    Solidified floating organic drop microextraction (SFODME) method in combination with graphite furnace atomic absorption spectrometry (GFAAS) has been used for the determination of chromium species in water and urine samples. 1-undecanol containing 2-thenoyltrifluoroacetone (TTA) was used as a selective chelating agent for the extraction of Cr(III). The total Cr was determined after the reduction of Cr(VI) to Cr(III) with hydroxylamine. The concentration of Cr(VI) was determined from the difference between the concentration of total chromium and the Cr(III). Several variables such as the sample pH, concentration of TTA, salt concentration, extraction time and the sample volume were investigated in detail. Under the optimum conditions, the limit of detection of the proposed method was 0.006 μg l-1 for Cr(III) and the relative standard deviation for six replicate determinations at 0.1 μg l-1 Cr(III) was 5.1%. The proposed method was successfully applied for the determination of chromium species in tap water, well water, mineral water, and urine samples.

  16. Speciation and determination of ultra trace amounts of chromium by solidified floating organic drop microextraction (SFODME) and graphite furnace atomic absorption spectrometry

    Moghadam, Masoud Rohani [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of); Dadfarnia, Shayessteh, E-mail: sdadfarnia@yazduni.ac.ir [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of); Haji Shabani, Ali Mohammad [Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741 (Iran, Islamic Republic of)

    2011-02-15

    Solidified floating organic drop microextraction (SFODME) method in combination with graphite furnace atomic absorption spectrometry (GFAAS) has been used for the determination of chromium species in water and urine samples. 1-undecanol containing 2-thenoyltrifluoroacetone (TTA) was used as a selective chelating agent for the extraction of Cr(III). The total Cr was determined after the reduction of Cr(VI) to Cr(III) with hydroxylamine. The concentration of Cr(VI) was determined from the difference between the concentration of total chromium and the Cr(III). Several variables such as the sample pH, concentration of TTA, salt concentration, extraction time and the sample volume were investigated in detail. Under the optimum conditions, the limit of detection of the proposed method was 0.006 {mu}g l{sup -1} for Cr(III) and the relative standard deviation for six replicate determinations at 0.1 {mu}g l{sup -1} Cr(III) was 5.1%. The proposed method was successfully applied for the determination of chromium species in tap water, well water, mineral water, and urine samples.

  17. Determination of trace amounts of rare earth elements in samarium, terbium and disprosium oxides by graphite furnace atomic-absorption spectrometry

    A graphite furnace atomic-absorption spectrometry method for the determination of neodymium, europium, terbium, dysprosium and yttrium at trace level in samarium oxide; of samarium, europium, dysprosium, holmium, erbium and yttrium in terbium oxide and of europium, terbium, holmium, erbium and yttrium in dysprosium oxide was established. The best pyrolysis and atomization temperatures were determined for each lanthanide considered. Calibration curves were obtained for the pure elements, for binary mixtures formed by the matrix and each of the lanthanides studied and, finally, for the complex mixtures constituted by the matrix and all the other lanthanide of the group under scrutiny. This study has been carried out to examine the interference of the presence of one lanthanide on the behaviour of the other, since a lack of linearity on the calibration curves has been observed in some cases. Detection and determination limits have been determined as well. The detection limits encountered were within the range 0.002 to 0.3% for different elements. The precision of the method expressed as the relative standard deviation was calculated for each element present in each of the matrices studied. The conclusion arrived at is that the method can be applied for determining the above mentioned lanthanides present in the matrices studied with purity up to 99.50%. (author)

  18. Automatic microemulsion preparation for metals determination in fuel samples using a flow-batch analyzer and graphite furnace atomic absorption spectrometry.

    Cunha, Francisco Antônio S; Sousa, Rafael A; Harding, David P; Cadore, Solange; Almeida, Luciano F; Araújo, Mário César U

    2012-05-21

    The principal thermodynamic advantages of using microemulsions over standard emulsions for flow metal analysis are the greatly increased analyte stability and emulsive homogeneity that improve both the ease of sample preparation, and the analytical result. In this study a piston propelled flow-batch analyzer (PFBA) for the determination of Cu, Cr and Pb in gasoline and naphtha by graphite furnace atomic absorption spectrometry (GF AAS) was explored. Investigative phase modeling for low dilution was conducted both for gasoline and naphtha microemulsions. Rheological considerations were also explored including a mathematical flow derivation to fine tune the system's operational parameters, and the GF AAS coupling. Both manual and automated procedures for microemulsion preparation were compared. The results of the paired t test at a 95% confidence level showed no significant differences between them. Further recovery test results confirmed a negligible matrix effect of the sample on the analyte absorption signals and an efficient stabilization of the samples (with metals) submitted to microemulsion treatment. The accuracy of the developed procedure was attested by good recovery percentages in the ranges of 100.0±3.5% for Pb in the naphtha samples, and 100.2±3.4% and 100.7±4.6% for Cu and Cr, respectively in gasoline samples. PMID:22541820

  19. Spectral aspects of the determination of Si in organic and aqueous solutions using high-resolution continuum source or line source flame atomic absorption spectrometry

    Kowalewska, Zofia; Pilarczyk, Janusz; Gościniak, Łukasz

    2016-06-01

    High-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was applied to reveal and investigate spectral interference in the determination of Si. An intensive structured background was observed in the analysis of both aqueous and xylene solutions containing S compounds. This background was attributed to absorption by the CS molecule formed in the N2O-C2H2 flame. The lines of the CS spectrum at least partially overlap all five of the most sensitive Si lines investigated. The 251.611 nm Si line was demonstrated to be the most advantageous. The intensity of the structured background caused by the CS molecule significantly depends on the chemical form of S in the solution and is the highest for the most-volatile CS2. The presence of O atoms in an initial S molecule can diminish the formation of CS. To overcome this S effect, various modes of baseline fitting and background correction were evaluated, including iterative background correction (IBC) and utilization of correction pixels (WRC). These modes were used either independently or in conjunction with least squares background correction (LSBC). The IBC + LSBC mode can correct the extremely strong interference caused by CS2 at an S concentration of 5% w:w in the investigated solution. However, the efficiency of this mode depends on the similarity of the processed spectra and the correction spectra in terms of intensity and in additional effects, such as a sloping baseline. In the vicinity of the Si line, three lines of V were recorded. These lines are well-separated in the HR-CS FAAS spectrum, but they could be a potential source of overcorrection when using line source flame atomic absorption spectrometry (LS FAAS). The expected signal for the 251.625 nm Fe line was not registered at 200 mg L- 1 Fe concentration in the solution, probably due to the diminished population of Fe atoms in the high-temperature flame used. The observations made using HR-CS FAAS helped to establish a "safe" level

  20. On-line solid-phase separation/preconcentration for the determination of copper in urine by flame atomic absorption spectrometry

    A new on-line separation/preconcentration system was developed for the determination of Cu(II) ions by flame atomic absorption spectrometry in urine samples. A newly synthesized chelating resin, by anchoring eriochrome blue black R reagent to Amberlite XAD-16 resin, was used as a packing material for the selective separation/preconcentration of Cu(II) ions. The influence of the parameters on the determination of Cu(II) ions such as pH of sample solution, amount of the resin, eluent type, interfering ions and flow variables was studied. The detection limit of the method was 1.0 μg L−1 while precision was 2.3% (n = 15) at 50 μg L−1 Cu(II) level. The adsorption capacity of the resin was 217 μg g−1 Cu(II). The accuracy of the method was proven using TMDA-64 standard lake water and synthetic urine sample. The developed method has been applied successfully to the determination of copper in urine with satisfactory results. - Highlights: • The method was applied to the urine samples taken from Wilson’s patients. • The on-line determination of copper and satisfactory results were obtained. • All processes are made automatically by the system itself in the proposed method

  1. Modified carbon nanotubes as a sorbent for solid-phase extraction of gold, and its determination by graphite furnace atomic absorption spectrometry

    A simple, sensitive and accurate method was developed for solid-phase extraction and preconcentration of trace levels of gold in various samples. It is based on the adsorption of gold on modified oxidized multi-walled carbon nanotubes prior to its determination by graphite furnace atomic absorption spectrometry. The type and volume of eluent solution, sample pH value, flow rates of sample and eluent, sorption capacity and breakthrough volume were optimized. Under these conditions, the method showed linearity in the range of 0.2–6.0 ng L−1 with coefficients of determination of >0.99 in the sample. The relative standard deviation for seven replicate determinations of gold (at a level of 0.6 ng L−1) is ±3.8 %, the detection limit is 31 pg L−1 (in the initial solution and at an S/N ratio of 3; for n = 8), and the enrichment factor is 200. The sorption capacity of the modified MWCNTs for gold(III) is 4.15 mg g−1. The procedure was successfully applied to the determination of gold in (spiked) water samples, human hair, human urine and standard reference material with recoveries ranging from 97.0 to 104.2 %. (author)

  2. Separation and preconcentration of trace quantities of copper ion using modified alumina nanoparticles, and its determination by flame atomic absorption spectrometry

    We report on a sensitive, reliable and relatively fast method for separation, preconcentration and determination of trace quantities of copper(II) ion. It is making use of nanometer-sized γ-alumina nanoparticles modified with sodium dodecyl sulfate (SDS). The adsorptive potential was assessed via a Langmuir isotherm and the maximal sorption capacity was found to be 138 mg g-1. The effects of pH values, amount of ligand, flow rate, type of eluting agent, volume of eluent, and the volume of sample were examined. The effects of interfering ions on the recovery of the analyte were also investigated. Copper ion was then determined by flame atomic absorption spectrometry. The relative standard deviation for five replicate determinations (at 50 μg L-1 of copper) is 3.3%. The detection limit (at 3 s) is 2.5 μg L-1. This method was validated with a certified reference material of oyster tissue (NIST SRM 1566b) and the results coincided well with the certified values. The procedure was successfully applied to the determination of Cu in water and food samples. (author)

  3. Ultrasound-assisted emulsification-microextraction combined with graphite furnace atomic absorption spectrometry for the determination of trace lead in water

    Jiang, Hongmei; Zhang, Yu; Qiu, Bocheng; Li, Wenhua [College of Science, Nanjing Agricultural University, Nan Jing (China)

    2012-04-15

    The ultrasound-assisted emulsification-microextraction (USAEME) method was combined with graphite furnace atomic absorption spectrometry (GFAAS) for the determination of trace Pb using dithizone (H{sup 2}DZ) as chelating reagent. Some effective parameters influenced the detection and microextraction, such as ashing temperature and atomization temperature, pH, extraction solvent, sample volume, extraction time, and extraction temperature were selected and optimized. After extraction, the calibration curves for Pb was in the concentration range of 0.1-10 ng mL{sup -1}, and the linear equation was y = 0.097 x + 0.023 (R = 0.99). Under the optimized conditions, the detection limit of the method was 20 pg mL{sup -1} with an enrichment factor of 70 and the relative standards deviation (RSD) for seven determinations of 1 ng mL{sup -1} Pb was 11%. The proposed method was successfully applied to determine trace Pb in Yueya Lake water, pond water, and spiked samples. Furthermore, a certified reference material of Environment Water (GBW08607) was analyzed and the determined value was in good agreement with the certified value, which showed the accuracy, recovery, and applicability of the reported method. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Speciation and determination of thallium by on-line microcolumn separation/preconcentration by flow injection-flame atomic absorption spectrometry using immobilized oxine as sorbent

    Dadfarnia, S. [Depatrment of Chemistry, Yazd University, Safaieh, 89195 Yazd (Iran, Islamic Republic of)], E-mail: Sdadfarnia@yazduni.ac.ir; Assadollahi, T.; Haji Shabani, A.M. [Depatrment of Chemistry, Yazd University, Safaieh, 89195 Yazd (Iran, Islamic Republic of)

    2007-09-05

    A flow injection analysis (FIA) system incorporation a microcolumn of immobilized oxine on surfactant-coated alumina had been devised for performing rapid thallium enrichment/matrix removal in flame atomic absorption spectrometry (FAA). The preconcentration is based on the deposition of thallium(I) on microcolumn and subsequent elution with 500 {mu}l of sodium thiosulfate (1 mol l{sup -1}). In the presence of EDTA, only Tl(I) was retained on the microcolumn. Total thallium was determined after reduction of Tl(III) to Tl(I) by hydroxyl amine hydrochloride. A sample volume of 25 ml resulted in a preconcentration factor of 77. Precision at 30 {mu}g l{sup -1} was 2.6% RSD (n = 10). With 25 ml sampling volume a detection limit of 2.5 {mu}g l{sup -1} was determined. The effect of potential interfering ions on the determination was studied. The method was applied for the determination of thallium in water, waste water, hair, nail, coal, and standard reference alloys. The accuracy was assessed through recovery experiment, independent analysis by Furnace-AAS, and analysis of certified reference alloys.

  5. Speciation and determination of thallium by on-line microcolumn separation/preconcentration by flow injection-flame atomic absorption spectrometry using immobilized oxine as sorbent

    A flow injection analysis (FIA) system incorporation a microcolumn of immobilized oxine on surfactant-coated alumina had been devised for performing rapid thallium enrichment/matrix removal in flame atomic absorption spectrometry (FAA). The preconcentration is based on the deposition of thallium(I) on microcolumn and subsequent elution with 500 μl of sodium thiosulfate (1 mol l-1). In the presence of EDTA, only Tl(I) was retained on the microcolumn. Total thallium was determined after reduction of Tl(III) to Tl(I) by hydroxyl amine hydrochloride. A sample volume of 25 ml resulted in a preconcentration factor of 77. Precision at 30 μg l-1 was 2.6% RSD (n = 10). With 25 ml sampling volume a detection limit of 2.5 μg l-1 was determined. The effect of potential interfering ions on the determination was studied. The method was applied for the determination of thallium in water, waste water, hair, nail, coal, and standard reference alloys. The accuracy was assessed through recovery experiment, independent analysis by Furnace-AAS, and analysis of certified reference alloys

  6. RAPID AND SENSITIVE DETERMINATION OF PALLADIUM USING HOMOGENEOUS LIQUID-LIQUID MICROEXTRACTION VIA FLOTATION ASSISTANCE FOLLOWED BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROMETRY

    Mohammad Rezaee

    2015-05-01

    Full Text Available A method for the determination of trace amounts of palladium was developed using homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA followed by graphite furnace atomic absorption spectrometry (GFAAS. Ammonium pyrrolidine dithiocarbamate (APDC was used as a complexing agent. This was applied to determine palladium in three types of water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added to the extraction cell which contained an appropriate mixture of extraction and homogeneous solvents. By using air flotation, the organic solvent was collected at the conical part of the designed cell. Parameters affecting extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration graph was linear in the range of 1.0-200 µg L-1 with a limit of detection of 0.3 µg L-1. The performance of the method was evaluated for the extraction and determination of palladium in water samples and satisfactory results were obtained. In order to verify the accuracy of the approach, the standard addition method was applied for the determination of palladium in spiked synthetic samples and satisfactory results were obtained.

  7. Arsenic and antimony determination in refined and unrefined table salts by means of hydride generation atomic absorption spectrometry--comparison of sample decomposition and determination methods

    AKSUNER, Nur; TİRTOM, Vedia Nüket; HENDEN, Emür

    2011-01-01

    An evaluation was made of different digestion methods for the determination of arsenic and antimony in table salt samples prior to hydride generation atomic absorption spectrometric analysis. Microwave acid digestion, classical wet digestion, dry ashing, and fusion were applied to the decomposition of salt samples and optimum conditions were investigated. Samples were decomposed by changing heating time, digestion techniques, and the amount and composition of acid, and then the concen...

  8. Determination of mercury in airborne particulate matter collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling

    Araujo, Rennan G.O., E-mail: rgoa01@terra.com.br [Laboratorio de Quimica Analitica Ambiental, Departamento de Quimica, Universidade Federal de Sergipe, Campus Sao Cristovao, 49.100-000, Sao Cristovao, SE (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Vignola, Fabiola; Castilho, Ivan N.B. [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Borges, Daniel L.G.; Welz, Bernhard [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Vale, Maria Goreti R. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, RS (Brazil); Smichowski, Patricia [Comision Nacional de Energia Atomica (CNEA) and Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, 40170-290, Salvador, BA (Brazil); Becker-Ross, Helmut [Leibniz-Institut fuer Analytische Wissenschaften-ISAS-e.V., Department Berlin, 12489 Berlin (Germany)

    2011-05-15

    A study has been undertaken to assess the capability of high-resolution continuum source graphite furnace atomic absorption spectrometry for the determination of mercury in airborne particulate matter (APM) collected on glass fiber filters using direct solid sampling. The main Hg absorption line at 253.652 nm was used for all determinations. The certified reference material NIST SRM 1648 (Urban Particulate Matter) was used to check the accuracy of the method, and good agreement was obtained between published and determined values. The characteristic mass was 22 pg Hg. The limit of detection (3{sigma}), based on ten atomizations of an unexposed filter, was 40 ng g{sup -1}, corresponding to 0.12 ng m{sup -3} in the air for a typical air volume of 1440 m{sup 3} collected within 24 h. The limit of quantification was 150 ng g{sup -1}, equivalent to 0.41 ng m{sup -3} in the air. The repeatability of measurements was better than 17% RSD (n = 5). Mercury concentrations found in filter samples loaded with APM collected in Buenos Aires, Argentina, were between < 40 ng g{sup -1} and 381 {+-} 24 ng g{sup -1}. These values correspond to a mercury concentration in the air between < 0.12 ng m{sup -3} and 1.47 {+-} 0.09 ng m{sup -3}. The proposed procedure was found to be simple, fast and reliable, and suitable as a screening procedure for the determination of mercury in APM samples.

  9. Determination of bismuth by dielectric barrier discharge atomic absorption spectrometry coupled with hydride generation: Method optimization and evaluation of analytical performance

    Kratzer, Jan; Boušek, J.; Sturgeon, R. E.; Mester, Z.; Dědina, Jiří

    2014-01-01

    Roč. 86, č. 19 (2014), s. 9620-9625. ISSN 0003-2700 Grant ostatní: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * hydride generation * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 5.636, year: 2014

  10. Selective Flow Injection Analysis of Ultra-trace Amounts of Cr(VI), Preconcentration of It by Solvent Extraction, and Determination by Electrothermal Atomic Absorption Spectrometry (ETAAS)

    Nielsen, Steffen; Sturup, Stefan; Spliid, Henrik;

    1999-01-01

    A rapid, robust, sensitive and selective time-based flow injection (FI) on-line solvent extraction system interfaced with electrothermal atomic absorption spectrometry (ETAAS) is described for analyzing ultra-trace amounts of Cr(VI). The sample is initially mixed on-line with isobutyl methyl ketone...

  11. In situ emulsification microextraction using a dicationic ionic liquid followed by magnetic assisted physisorption for determination of lead prior to micro-sampling flame atomic absorption spectrometry

    Shokri, Masood; Beiraghi, Asadollah [Faculty of Chemistry, Kharazmi University, Tehran (Iran, Islamic Republic of); Seidi, Shahram, E-mail: s.seidi@kntu.ac.ir [Department of Analytical Chemistry, Faculty of Chemistry, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2015-08-19

    For the first time, a simple and efficient in situ emulsification microextraction method using a dicationic ionic liquid followed by magnetic assisted physisorption was presented to determine trace amounts of lead. In this method, 400 μL of 1.0 mol L{sup −1} lithium bis (trifluoromethylsulfonyl) imide aqueous solution, Li[NTf{sub 2}], was added into the sample solution containing 100 μL of 1.0 mol L{sup −1} 1,3-(propyl-1,3-diyl) bis (3-methylimidazolium) chloride, [pbmim]Cl{sub 2}, to form a water immiscible ionic liquid, [pbmim][NTf{sub 2}]{sub 2}. This new in situ formed dicationic ionic liquid was applied as the acceptor phase to extract the lead-ammonium pyrrolidinedithiocarbamate (Pb-APDC) complexes from the sample solution. Subsequently, 30 mg of Fe{sub 3}O{sub 4} magnetic nanoparticles (MNPs) were added into the sample solution to collect the fine droplets of [pbmim][NTf{sub 2}]{sub 2}, physisorptively. Finally, MNPs were eluted by acetonitrile, separated by an external magnetic field and the obtained eluent was subjected to micro-sampling flame atomic absorption spectrometry (FAAS) for further analysis. Comparing with other microextraction methods, no special devices and centrifugation step are required. Parameters influencing the extraction efficiency such as extraction time, pH, concentration of chelating agent, amount of MNPs and coexisting interferences were studied. Under the optimized conditions, this method showed high extraction recovery of 93% with low LOD of 0.7 μg L{sup −1}. Good linearity was obtained in the range of 2.5–150 μg L{sup −1} with determination coefficient (r{sup 2}) of 0.9921. Relative standard deviation (RSD%) for seven repeated measurements at the concentration of 10 μg L{sup −1} was 4.1%. Finally, this method was successfully applied for determination of lead in some water and plant samples. - Highlights: • A dicationic ionic liquid was used as the extraction solvent, for the first time. • A

  12. Salt-assisted liquid-liquid microextraction of Cr(VI) ion using an ionic liquid for preconcentration prior to its determination by flame atomic absorption spectrometry

    We report on the salt-assisted liquid-liquid microextraction of cationic complexes of Cr(VI) ion using the hydrophilic ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoraborate and potassium hydrogen phosphate. This is a novel, simple, non-toxic and effective technique for sample pretreatment technique that displays large extraction efficiency and represents a new platform where Cr(VI) is complexed with 1,5-diphenylcarbazide (DPC) in sulfuric acid medium. It was applied to the extraction of Cr(VI) in the form of the Cr(VI)-DPC complex prior to its determination by flame atomic absorption spectrometry. Cr(III) ion also can be determined by this procedure after oxidation to Cr(VI). Extraction is mainly affected by the amount of water-soluble IL, the kind and quantity of inorganic salts, by pH and the concentration of DPC. Calibration plots are linear in the range from 3 to 150 μg L-1 of Cr(VI), and the limit of detection is 1. 25 μg L-1. The method was successfully applied to the speciation and determination of trace levels of Cr(III) and Cr(VI) in environmental water samples containing high levels of dissolved salts or food grade salts. (author)

  13. Cloud Point Extraction for the Determination of Trace Amounts of Cobalt in Water and Food Samples by Flame Atomic Absorption Spectrometry

    Shangzhi Wang

    2013-01-01

    Full Text Available A cloud point extraction (CPE procedure which was developed for the separation and preconcentration of trace amounts of cobalt is combined with flame atomic absorption spectrometry (FAAS to determine trace amounts of cobalt in water and food samples. The procedure is based on the formation of the hydrophobic complex between Co(II and 4-methoxy-2-sulfo-benzenediazoaminoazo-benzene (MOSDAA followed by its extraction into a Triton X-114 surfactant-rich phase. The parameters such as pH of sample, concentrations of MOSDAA and Triton X-114, equilibrium temperature, and equilibrium time, which affect both complexation and extraction, are optimized. Under the selected optimum conditions, the preconcentration of 10.0 mL, 0.1 μg mL−1 Co(II solution results in a limit of detection of 0.47 ng mL−1 (3σ and an enrichment factor of 19. A relative standard deviation of 2.78% (,  μg mL−1 for the determination of Co(II is obtained. The proposed method was applied for the determination of trace amounts of cobalt in river water and millet samples with satisfactory results.

  14. A Green Preconcentration Method for Determination of Cobalt and Lead in Fresh Surface and Waste Water Samples Prior to Flame Atomic Absorption Spectrometry

    Naeemullah

    2012-01-01

    Full Text Available Cloud point extraction (CPE has been used for the preconcentration and simultaneous determination of cobalt (Co and lead (Pb in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114, temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS. The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample.

  15. A novel ionic liquid/micro-volume back extraction procedure combined with flame atomic absorption spectrometry for determination of trace nickel in samples of nutritional interest

    Dadfarnia, Shayesteh, E-mail: sdadfarnia@yazduni.ac.ir [Department of Chemistry, Faculty of Science, Yazd University, 89195/74, Yazd (Iran, Islamic Republic of); Haji Shabani, Ali Mohammad; Shirani Bidabadi, Mahboubeh; Jafari, Abbas Ali [Department of Chemistry, Faculty of Science, Yazd University, 89195/74, Yazd (Iran, Islamic Republic of)

    2010-01-15

    A simple, highly sensitive and environment-friendly method for the determination of trace amount of nickel ion in different matrices is proposed. In the preconcentration step, the nickel from 10 mL of an aqueous solution was extracted into 500 {mu}L of ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C{sub 4}MIM][PF{sub 6}], containing PAN as complexing agent. Subsequently, the PAN complex was back-extracted into 250 {mu}L of nitric acid solution, and 100 {mu}L of it was analyzed by flow injection flame atomic absorption spectrometry (FI-FAAS). The main parameter influencing the extraction and determination of nickel, such as pH, concentration of PAN, extraction time and temperature, ionic strength, and concentration of stripping acid solution, were optimized. An enhancement factor of 40.2 was achieved with 25 mL sample. The limit of detection (LOD) and quantification obtained under the optimum conditions were 12.5 and 41.0 {mu}g L{sup -1}, respectively. To validate the proposed methods two certified reference materials 681-I and BCR No. 288 were analyzed and the results were in good agreement with the certified values. The proposed method was successfully applied to determination of nickel in water samples, rice flour and black tea.

  16. A novel ionic liquid/micro-volume back extraction procedure combined with flame atomic absorption spectrometry for determination of trace nickel in samples of nutritional interest

    A simple, highly sensitive and environment-friendly method for the determination of trace amount of nickel ion in different matrices is proposed. In the preconcentration step, the nickel from 10 mL of an aqueous solution was extracted into 500 μL of ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6], containing PAN as complexing agent. Subsequently, the PAN complex was back-extracted into 250 μL of nitric acid solution, and 100 μL of it was analyzed by flow injection flame atomic absorption spectrometry (FI-FAAS). The main parameter influencing the extraction and determination of nickel, such as pH, concentration of PAN, extraction time and temperature, ionic strength, and concentration of stripping acid solution, were optimized. An enhancement factor of 40.2 was achieved with 25 mL sample. The limit of detection (LOD) and quantification obtained under the optimum conditions were 12.5 and 41.0 μg L-1, respectively. To validate the proposed methods two certified reference materials 681-I and BCR No. 288 were analyzed and the results were in good agreement with the certified values. The proposed method was successfully applied to determination of nickel in water samples, rice flour and black tea.

  17. Study of the roles of chemical modifiers in determining boron using graphite furnace atomic absorption spectrometry and optimization of the temperature profile during atomization

    The measurement conditions for determining boron using graphite furnace–atomic absorption spectrometry (GF-AAS) were investigated. Differences in the boron absorbance profiles were found using three different commercially available GF-AAS instruments when the graphite atomizers in them were not tuned. The boron absorbances found with and without adjusting the graphite atomizers suggested that achieving an adequate absorbance for the determination of boron requires a sharp temperature profile that overshoots the target temperature during the atomization process. Chemical modifiers that could improve the boron absorbance without the need for using coating agents were tested. Calcium carbonate improved the boron absorbance but did not suppress variability in the peak height. Improvement of boron absorbance was comparatively less using iron nitrate or copper nitrate than using calcium carbonate, but variability in the peak height was clearly suppressed using iron nitrate or copper nitrate. The limit of detection was 0.0026 mg L−1 when iron nitrate was used. It appears that iron nitrate is a useful new chemical modifier for the quick and simple determination of boron using GF-AAS. (author)

  18. An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.

    Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G

    2016-08-15

    A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. PMID:27260436

  19. Ultrasound-assisted emulsification solidified floating organic drops microextraction of ultra trace amount of Te (IV) prior to graphite furnace atomic absorption spectrometry determination.

    Fathirad, Fariba; Afzali, Daryoush; Mostafavi, Ali; Ghanbarian, Maryam

    2012-01-15

    In the present study, a new, simple and efficient method for the preconcentration of ultra trace amounts of Te (IV) is developed using ultrasound-assisted emulsification solidified floating organic drops microextraction (USAE-SFODME) before graphite furnace atomic absorption spectrometry determination. In this method, tellurium is extracted into the fine droplets of 1-undecanol after chelate formation with the water soluble ligand, ammonium pyrrolidinedithiocarbamate (APDC). Several factors such as pH, chelating agent amount, type and volume of the extracting solvent, sonication and centrifuging time that influence the extraction and complex formation are optimized. Under the optimum conditions, the calibration graph is linear in the range of 0.01-0.24ngmL(-1) of tellurium in the original solution, with limit of detection of 0.003ngmL(-1). The relative standard deviation (RSD) for seven replicated determinations of tellurium ion at 0.08ngmL(-1) concentration level is calculated as 3.4%. The proposed method was successfully applied to the determination of Te (IV) in a standard soil and several water samples. PMID:22265571

  20. Ultra-trace determination of lead in water and food samples by using ionic liquid-based single drop microextraction-electrothermal atomic absorption spectrometry.

    Manzoori, Jamshid L; Amjadi, Mohammad; Abulhassani, Jafar

    2009-06-30

    An improved single drop microextraction procedure was developed for the preconcentration of lead prior to its determination by electrothermal atomic absorption spectrometry. Ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6], was used as an alternative to volatile organic solvents for extraction. Lead was complexed with ammonium pyrroldinedithiocarbamate (APDC) and extracted into a 7-microL ionic liquid drop. The extracted complex was directly injected into the graphite furnace. Several variables affecting microextraction efficiency and ETAAS signal, such as pyrolysis and atomization temperature, pH, APDC concentration, extraction time, drop volume and stirring rate were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enhancement factor were 0.015 microg L(-1) and 76, respectively. The relative standard deviation (RSD) for five replicate determinations of 0.2 microg L(-1) Pb was 5.2%. The developed method was validated by the analysis of certified reference materials and applied successfully to the determination of lead in several real samples. PMID:19463561

  1. Application of l-cystine modified zeolite for preconcentration and determination of ultra-trace levels of cadmium by flame atomic absorption spectrometry.

    Rezvani, Seyyed Ahmad; Soleymanpour, Ahmad

    2016-03-01

    A very convenient, sensitive and precise solid phase extraction (SPE) system was developed for enrichment and determination of ultra-trace of cadmium ion in water and plant samples. This method was based on the retention of cadmium(II) ions by l-cystine adsorbed in Y-zeolite and carry out in a packed mini-column. The retained cadmium ions then were eluted and determined by flame atomic absorption spectrometry. The scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy techniques were applied for the characterization of cystine modified zeolite (CMZ). Some experimental conditions affecting the analytical performance such as pH, eluent type, concentration of sample, eluent flow rate and also the presence of interfering ions were investigated. The calibration graph was linear within the range of 0.1-7.5ngmL(-1) and limit of detection was obtained 0.04ngmL(-1) with the preconcentration factor of 400. The relative standard deviation (RSD) was obtained 1.4%, indicating the excellent reproducibility of this method. The proposed method was successfully applied for the extraction and determination of cadmium(II) ion in black tea, cigarette's tobacco and also various water samples. PMID:26852265

  2. Direct determination of arsenic and antimony in naphtha by electrothermal atomic absorption spectrometry with microemulsion sample introduction and iridium permanent modifier

    Cassella, Ricardo J. [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, 24020-007, Niteroi/RJ (Brazil); Barbosa, Bruno Alberto R.S.; Santelli, Ricardo E. [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro de Sao Joao Batista s/n, Centro, 24020-007, Niteroi/RJ (Brazil); Rangel, Alessandra T. [PETROBRAS, CENPES, PDEDS/QM, Rio de Janeiro (Brazil)

    2004-05-01

    This paper reports the determination of arsenic and antimony in naphtha by employing electrothermal atomic absorption spectrometry (ETAAS) as the analytical technique. In order to promote the direct determination of the analytes in the very volatile naphtha, the formation of a microemulsion with different surfactants (Triton X-100 and Brij-35) and different chemical modification strategies were tested. The results indicated that Triton X-100 is the best emulsification agent for naphtha in both As and Sb determination when it is employed at a concentration of 1% w/v in the microemulsion. Under these conditions, the microemulsion was stabile for at least 2 h. By using Brij-35 it was possible to achieve good stability only in the first 15 min. Among all chemical modification approaches investigated (Ir permanent modifier, W-Ir permanent modifier, and Pd modifier), the Ir permanent modifier provided better sensitivity for both analytes and allowed a higher pyrolysis temperature, which decreased the background signals at lower levels. Under the best conditions established in this work, an RSD of 4.6% (20 {mu}g L{sup -1}) and a detection limit of 2.7 {mu}g L{sup -1} were observed for arsenic. For antimony, an RSD of 4.0% (20 {mu}g L{sup -1}) and a detection limit of 2.5 {mu}g L{sup -1} were obtained. The accuracy of the procedure was assessed by analyzing spiked samples of naphtha from different origins. (orig.)

  3. Feasibility of internal standardization in the direct and simultaneous determination of As, Cu and Pb in sugar-cane spirits by graphite furnace atomic absorption spectrometry

    Bismuth and Sb were evaluated as internal standards (IS) to minimize matrix effects on the direct and simultaneous determination of As, Cu, and Pb in cachaca by graphite furnace atomic absorption spectrometry using W-coated platform plus Pd-Mg(NO3)2 as modifier. For 20 μL injected sample, calibration within the 0.5-10 μg L-1 As, 100-1000 μg L-1 Cu and 0.5-30 μg L-1 Pb intervals were established using the ratios As absorbance to Sb absorbance, Cu absorbance to Bi absorbance and Pb absorbance to Bi absorbance versus analytes concentration, respectively. Typical linear correlations of 0.998, 0.999 and 0.999 were, respectively, obtained. The proposed method was applied for direct determination of As, Cu and Pb in 10 commercial cachaca samples and results were in agreement with those obtained by inductively coupled plasma mass spectrometry at 95% confidence level. The found characteristic masses were 30 pg As, 274 pg Cu and 39 pg Pb. The useful lifetime of the graphite tube was around 760 firings. Recoveries of As, Cu and Pb added to cachaca samples varied, respectively, from 98% to 109%, 97% to 108% and 98% to 104% with internal standards and from 48% to 54%, 53% to 92% and 62% to 97% without internal standards. The limits of detection were 0.13 μg L-1 As, 22 μg L-1 Cu and 0.05 μg L-1 Pb. The relative standard deviations (n = 12) for a spiked sample containing 20 μg L-1 As, Pb and 500 μg L-1 Cu were 1.6%, 1.0%, and 1.8% with IS and 4.3%, 5.2%, and 5.5% without IS

  4. Simultaneous determination of iron and nickel in fluoropolymers by solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Soares, Bruno M; Santos, Rafael F; Bolzan, Rodrigo C; Muller, Edson I; Primel, Ednei G; Duarte, Fabio A

    2016-11-01

    This paper reports the development of a method of simultaneous determination of iron and nickel in fluoropolymers by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) with direct solid sampling. In order to carry out simultaneous measurements, both the main resonance line of nickel (232.003nm) and the adjacent secondary line of iron (232.036nm) were monitored in the same spectral window. The proposed method was optimized with a perfluoroalkoxy (PFA) sample and was applied to the determination of iron and nickel in fluorinated ethylene propylene (FEP) and modified polytetrafluoroethylene (PTFE-TFM) samples. Pyrolysis and atomization temperatures, as well as the use of Pd and H2 (during pyrolysis) as chemical modifiers, were carefully investigated. Compromise temperatures for pyrolysis and atomization of both analytes were achieved at 800 and 2300°C, respectively, using only 0.5Lmin(-1) H2 as chemical modifier during pyrolysis. Calibration curves were performed with aqueous standards by using a single solution which contained both analytes. Limits of detection were 221 and 9.6ngg(-1) for iron and nickel, respectively. Analyte concentrations in all samples ranged from 3.53 to 12.4µgg(-1) for iron and from 37 to 78ngg(-1) for nickel, with relative standard deviation less than 19%. Accuracy was evaluated by comparing these results with those obtained by inductively coupled plasma mass spectrometry after sample digestion by microwave-induced combustion and no significant statistical difference was observed. PMID:27591638

  5. Investigation of spectral interferences in the determination of lead in fertilizers and limestone samples using high-resolution continuum source graphite furnace atomic absorption spectrometry

    In the present work, spectral interferences on the determination of lead in fertilizer and limestone samples were investigated using high-resolution continuum source graphite furnace atomic absorption spectrometry at the main analytical lines: 217.001 and 283.306 nm. For these investigations, samples were introduced into the furnace as slurry together with a mixture of Pd and Mg as chemical modifier. Spectral interferences were observed for some samples at both analytical lines. In order to verify whether a wet digestion procedure would avoid these interferences, a reference method for wet digestion of fertilizers was employed as an alternative sample preparation procedure. However, the same interferences were also observed in the digested samples. In order to identify and eliminate the fine-structured background using a least-squares background correction, reference spectra were generated using the combination of different species. The use of the latter technique allowed the elimination of spectral interferences for most of the investigated samples, making possible the determination of lead in fertilizer and limestone samples free of interferences. The best results were found using a reference spectrum of NH4H2PO4 at 217.001 nm, and a mixture of H2SO4 + Ca and HNO3 + Ca at the 283.306 nm line. The accuracy of the method was evaluated using a certified reference material “Trace Elements in Multi-Nutrient Fertilizer”. Similar results were obtained using line source graphite furnace atomic absorption spectrometry with Zeeman-effect background correction, indicating that the latter technique was also capable to correct the spectral interferences, at least in part. - Highlights: • Spectral interferences on the determination of lead in fertilizers and limestone. • The analytical lines at 217.001 nm and 283.306 nm using HR-CS GF AAS. • Various combinations of compounds were used to create reference spectra. • LSBC eliminated spectral interferences for most of

  6. Investigation of spectral interferences in the determination of lead in fertilizers and limestone samples using high-resolution continuum source graphite furnace atomic absorption spectrometry

    Borges, Aline R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Becker, Emilene M.; François, Luciane L.; Jesus, Alexandre de [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Dessuy, Morgana B., E-mail: mbdessuy@ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil)

    2014-11-01

    In the present work, spectral interferences on the determination of lead in fertilizer and limestone samples were investigated using high-resolution continuum source graphite furnace atomic absorption spectrometry at the main analytical lines: 217.001 and 283.306 nm. For these investigations, samples were introduced into the furnace as slurry together with a mixture of Pd and Mg as chemical modifier. Spectral interferences were observed for some samples at both analytical lines. In order to verify whether a wet digestion procedure would avoid these interferences, a reference method for wet digestion of fertilizers was employed as an alternative sample preparation procedure. However, the same interferences were also observed in the digested samples. In order to identify and eliminate the fine-structured background using a least-squares background correction, reference spectra were generated using the combination of different species. The use of the latter technique allowed the elimination of spectral interferences for most of the investigated samples, making possible the determination of lead in fertilizer and limestone samples free of interferences. The best results were found using a reference spectrum of NH{sub 4}H{sub 2}PO{sub 4} at 217.001 nm, and a mixture of H{sub 2}SO{sub 4} + Ca and HNO{sub 3} + Ca at the 283.306 nm line. The accuracy of the method was evaluated using a certified reference material “Trace Elements in Multi-Nutrient Fertilizer”. Similar results were obtained using line source graphite furnace atomic absorption spectrometry with Zeeman-effect background correction, indicating that the latter technique was also capable to correct the spectral interferences, at least in part. - Highlights: • Spectral interferences on the determination of lead in fertilizers and limestone. • The analytical lines at 217.001 nm and 283.306 nm using HR-CS GF AAS. • Various combinations of compounds were used to create reference spectra. • LSBC

  7. Determination of Ultra-trace Amounts of Arsenic(III) by Flow Injection Hydride Generation Atomic Absorption Spectrometry with On-line Preconcentration by Coprecipitation with Lanthanum Hydroxide or Hafnium Hydroxide

    Nielsen, Steffen; Sloth, Jens Jørgen; Hansen, Elo Harald

    1996-01-01

    A time-based flow-injection (FI) procedure for the determination of ultra-trace amounts of inorganic arsenic(III) is described, which combines hydride generation atomic absorption spectrometry (HG-AAS) with on-line preconcentration of the analyte by inorganic coprecipitation-dissolution in a...

  8. Determination of Ultra-Trace Amounts of Selenium(IV) by Flow Injection Hydride Generation Atomic Absorption Spectrometry with On-line Preconcentration by Co-precipitation with Lanthanium Hydroxide. Part II. On-line Addition of Coprecipating Agent

    Nielsen, Steffen; Sloth, Jens Jørgen; Hansen, Elo Harald

    1996-01-01

    A flow injection procedure for the determination of ultra-trace amounts of selenium(IV) is described, which combines hydride generation atomic absorption spectrometry (HGAAS) with on-line preconcentration of the analyte by co-precipitation-dissolution in a filterless knotted Microline reactor...

  9. Peat as a natural solid-phase for copper preconcentration and determination in a multicommuted flow system coupled to flame atomic absorption spectrometry

    Gonzales, A.P.S. [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia, 166, 09210-170 Santo Andre (Brazil); Firmino, M.A. [Departamento de Engenharia de Materiais, Escola de Engenharia, Universidade Presbiteriana Mackenzie, Rua da Consolacao, 930, 01302-970 Sao Paulo (Brazil); Nomura, C.S. [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia, 166, 09210-170 Santo Andre (Brazil); Rocha, F.R.P.; Oliveira, P.V. [Departamento de Quimica Fundamental, Instituto de Quimica, Universidade de Sao Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 Sao Paulo (Brazil); Gaubeur, I. [Centro de Ciencias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adelia, 166, 09210-170 Santo Andre (Brazil)], E-mail: ivanise.gaubeur@ufabc.edu.br

    2009-03-23

    The physical and chemical characteristics of peat were assessed through measurement of pH, percentage of organic matter, cationic exchange capacity (CEC), elemental analysis, infrared spectroscopy and quantitative analysis of metals by ICP OES. Despite the material showed to be very acid in view of the percentage of organic matter, its CEC was significant, showing potential for retention of metal ions. This characteristic was exploited by coupling a peat mini-column to a flow system based on the multicommutation approach for the in-line copper concentration prior to flame atomic absorption spectrometric determination. Cu(II) ions were adsorbed at pH 4.5 and eluted with 0.50 mol L{sup -1} HNO{sub 3}. The influence of chemical and hydrodynamic parameters, such as sample pH, buffer concentration, eluent type and concentration, sample flow-rate and preconcentration time were investigated. Under the optimized conditions, a linear response was observed between 16 and 100 {mu}g L{sup -1}, with a detection limit estimated as 3 {mu}g L{sup -1} at the 99.7% confidence level and an enrichment factor of 16. The relative standard deviation was estimated as 3.3% (n = 20). The mini-column was used for at least 100 sampling cycles without significant variation in the analytical response. Recoveries from copper spiked to lake water or groundwater as well as concentrates used in hemodialysis were in the 97.3-111% range. The results obtained for copper determination in these samples agreed with those achieved by graphite furnace atomic absorption spectrometry (GFAAS) at the 95% confidence level.

  10. Automatic microemulsion preparation for metals determination in fuel samples using a flow-batch analyzer and graphite furnace atomic absorption spectrometry

    Highlights: ► Micro-emulsion composition phase study to obtain low fuel dilutions. ► Automated and instantaneous in-line preparation of micro-emulsions for metals determinations. ► A versatile piston-driven form of “Flow-batch Analysis”. ► Rheological considerations explored including a mathematical derivation of flow parameters. - Abstract: The principal thermodynamic advantages of using microemulsions over standard emulsions for flow metal analysis are the greatly increased analyte stability and emulsive homogeneity that improve both the ease of sample preparation, and the analytical result. In this study a piston propelled flow-batch analyzer (PFBA) for the determination of Cu, Cr and Pb in gasoline and naphtha by graphite furnace atomic absorption spectrometry (GF AAS) was explored. Investigative phase modeling for low dilution was conducted both for gasoline and naphtha microemulsions. Rheological considerations were also explored including a mathematical flow derivation to fine tune the system's operational parameters, and the GF AAS coupling. Both manual and automated procedures for microemulsion preparation were compared. The results of the paired t test at a 95% confidence level showed no significant differences between them. Further recovery test results confirmed a negligible matrix effect of the sample on the analyte absorption signals and an efficient stabilization of the samples (with metals) submitted to microemulsion treatment. The accuracy of the developed procedure was attested by good recovery percentages in the ranges of 100.0 ± 3.5% for Pb in the naphtha samples, and 100.2 ± 3.4% and 100.7 ± 4.6% for Cu and Cr, respectively in gasoline samples.

  11. Automatic microemulsion preparation for metals determination in fuel samples using a flow-batch analyzer and graphite furnace atomic absorption spectrometry

    Cunha, Francisco Antonio S. [Universidade Federal da Paraiba, CCEN, Departamento de Quimica, P. Box 5093, 58051-970, Joao Pessoa, PB (Brazil); Sousa, Rafael A. [Institute of Chemistry-University of Campinas, P.O. Box 6154, 13083-970, Campinas, SP (Brazil); Harding, David P. [Universidade Federal da Paraiba, CCEN, Departamento de Quimica, P. Box 5093, 58051-970, Joao Pessoa, PB (Brazil); Cadore, Solange [Institute of Chemistry-University of Campinas, P.O. Box 6154, 13083-970, Campinas, SP (Brazil); Almeida, Luciano F. [Universidade Federal da Paraiba, CCEN, Departamento de Quimica, P. Box 5093, 58051-970, Joao Pessoa, PB (Brazil); Araujo, Mario Cesar U., E-mail: laqa@quimica.ufpb.br [Universidade Federal da Paraiba, CCEN, Departamento de Quimica, P. Box 5093, 58051-970, Joao Pessoa, PB (Brazil)

    2012-05-21

    Highlights: Black-Right-Pointing-Pointer Micro-emulsion composition phase study to obtain low fuel dilutions. Black-Right-Pointing-Pointer Automated and instantaneous in-line preparation of micro-emulsions for metals determinations. Black-Right-Pointing-Pointer A versatile piston-driven form of 'Flow-batch Analysis'. Black-Right-Pointing-Pointer Rheological considerations explored including a mathematical derivation of flow parameters. - Abstract: The principal thermodynamic advantages of using microemulsions over standard emulsions for flow metal analysis are the greatly increased analyte stability and emulsive homogeneity that improve both the ease of sample preparation, and the analytical result. In this study a piston propelled flow-batch analyzer (PFBA) for the determination of Cu, Cr and Pb in gasoline and naphtha by graphite furnace atomic absorption spectrometry (GF AAS) was explored. Investigative phase modeling for low dilution was conducted both for gasoline and naphtha microemulsions. Rheological considerations were also explored including a mathematical flow derivation to fine tune the system's operational parameters, and the GF AAS coupling. Both manual and automated procedures for microemulsion preparation were compared. The results of the paired t test at a 95% confidence level showed no significant differences between them. Further recovery test results confirmed a negligible matrix effect of the sample on the analyte absorption signals and an efficient stabilization of the samples (with metals) submitted to microemulsion treatment. The accuracy of the developed procedure was attested by good recovery percentages in the ranges of 100.0 {+-} 3.5% for Pb in the naphtha samples, and 100.2 {+-} 3.4% and 100.7 {+-} 4.6% for Cu and Cr, respectively in gasoline samples.

  12. Ultrasound-assisted ion-pair dispersive liquid-liquid microextraction of trace amounts of lead in water samples prior to graphite furnace atomic absorption spectrometry determination.

    Afzali, Daryoush; Mohadesi, Ali Reza; Falahnejad, Masoumeh; Bahadori, Behnoosh

    2013-01-01

    A new ion-pair dispersive liquid-liquid microextraction method is described for separation and preconcentration of trace amounts of lead in different water samples. Graphite furnace atomic absorption spectrometry was used for determination of lead. The ion association complex between lead and iodide ions that forms is PbI4(-2)-tetradecyl-dimethylbenzylammonium, which is extracted into fine droplets of chlorobenzene. In order to reach the optimized experimental conditions, the influence of different parameters, such as concentration of KI, nature and volume of extraction solvents, pH effect, extraction time, and the period and speed of sonication and centrifugation, were optimized. The LOD was 0.08 ng/mL and the linear dynamic range was 0.20-8.0 ng/mL in initial solution with a correlation coefficient of 0.9985. Under the optimum conditions, the enrichment factor was 555.5. The proposed method was successfully applied for separation and determination of lead in sea, rain, river, and drinking water samples. PMID:23513972

  13. Multivariate optimization of ultrasound-assisted extraction for determination of Cu, Fe, Ni and Zn in vegetable oils by high-resolution continuum source atomic absorption spectrometry.

    Trindade, Alex S N; Dantas, Alailson F; Lima, Daniel C; Ferreira, Sérgio L C; Teixeira, Leonardo S G

    2015-10-15

    An assisted liquid-liquid extraction of copper, iron, nickel and zinc from vegetable oil samples with subsequent determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) was optimized by applying a full factorial design in two levels and the response surface methodology, Box-Behnken. The effects of the acid concentration and the amplitude, cycle and time of sonication on the extraction of the analytes, as well as their interactions, were assessed. In the selected condition (sonication amplitude = 66%, sonication time = 79 s, sonication cycle = 74%), using 0.5 mol L(-1) HCl as the extractant, the limits of quantification were 0.14, 0.20, 0.21 and 0.04 μg g(-1) for Cu, Fe, Ni and Zn, respectively, with R.S.D. ranging from 1.4% to 3.6%. The proposed method was applied for the determination of the analytes in soybean, canola and sunflower oils. PMID:25952852

  14. Trace mercury determination in drinking and natural water after preconcentration and separation by DLLME-SFO method coupled with cold vapor atomic absorption spectrometry

    Abdollahi Atousa

    2014-07-01

    Full Text Available A novel dispersive liquid–liquid microextraction based on solidification of floating organic drop (DLLME-SFO for simultaneous separation/preconcentration of ultra trace amounts of mercury was used. A method based on amalgamation was used for collection of gaseous mercury on gold coated sand (Gold trap. The concentration of mercury was determined by cold vapor atomic absorption spectrometry (CV-AAS. The DLLME-SFO behavior of mercury by using dithizone as complexing agent was systematically investigated. The factors influencing, the complex formation and extraction of DLLME-SFO method such as type and volume of extraction and disperser solvents, pH, concentration of salt, centrifuging time and concentration of the chelating agent were optimized. The method was successfully applied to the determination of mercury in drinking and natural water and satisfactory relative recoveries (95–105% were achieved. The proposed procedure was based on very low consumption of organic solvents. The other benefits of the system were sensitive, simple, friendly to the environment, rejection of matrix constituent, low cost, the time consuming and high enrichment factor.

  15. Modified ionic liquid cold-induced aggregation dispersive liquid-liquid microextraction followed by atomic absorption spectrometry for trace determination of zinc in water and food samples

    We report on a new method for the microextraction and determination of zinc (II). The ion is accumulated via ionic-liquid cold-induced aggregation dispersive liquid-liquid microextraction (IL-CIA-DLLME) followed by flame atomic absorption spectrometry (FAAS). The ionic liquid (IL) 1-hexyl-3-methylimidazolium hexafluorophosphate is dispersed into a heated sample solution containing sodium hexafluorophosphate as a common ion source. The solution is then placed in an ice-water bath upon which a cloudy solution forms due to the decrease of the solubility of the IL. Zinc is complexed with 8-hydroxyquinoline and extracted into the IL. The enriched phase is dissolved in a diluting agent and introduced to the FAAS. The method is not influenced by variations in the ionic strength of the sample solution. Factors affecting the performance were evaluated and optimized. At optimum conditions, the limit of detection is 0.18 μg L-1, and the relative standard deviation is 3.0% (at n=5). The method was validated by recovery experiments and by analyzing a certified reference material and successfully applied to the determination of Zn (II) in water and food samples. (author)

  16. Solidified floating organic drop microextraction (SFODME) for simultaneous separation/preconcentration and determination of cobalt and nickel by graphite furnace atomic absorption spectrometry (GFAAS)

    Solidified floating organic drop microextraction (SFODME), combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for simultaneous separation/enrichment and determination of trace amounts of nickel and cobalt in surface waters and sea water. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of PAN, extraction time, stirring rate, extraction temperature, sample volume and nature of the solvent were optimized. Under the optimum experimental conditions, a good relative standard deviation for six determination of 20 ng l-1 of Co(II) and Ni(II) were 4.6 and 3.6%, respectively. An enrichment factor of 502 and 497 and detection limits of 0.4 and 0.3 ng l-1 for cobalt and nickel were obtained, respectively. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.

  17. Solidified floating organic drop microextraction (SFODME) for simultaneous separation/preconcentration and determination of cobalt and nickel by graphite furnace atomic absorption spectrometry (GFAAS)

    Bidabadi, Mahboubeh Shirani [Department of Chemistry, Yazd University, Safaieh, 89195 Yazd (Iran, Islamic Republic of); Dadfarnia, Shayessteh, E-mail: sdadfarnia@yazduni.ac.ir [Department of Chemistry, Yazd University, Safaieh, 89195 Yazd (Iran, Islamic Republic of); Shabani, Ali Mohammad Haji [Department of Chemistry, Yazd University, Safaieh, 89195 Yazd (Iran, Islamic Republic of)

    2009-07-15

    Solidified floating organic drop microextraction (SFODME), combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for simultaneous separation/enrichment and determination of trace amounts of nickel and cobalt in surface waters and sea water. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of PAN, extraction time, stirring rate, extraction temperature, sample volume and nature of the solvent were optimized. Under the optimum experimental conditions, a good relative standard deviation for six determination of 20 ng l{sup -1} of Co(II) and Ni(II) were 4.6 and 3.6%, respectively. An enrichment factor of 502 and 497 and detection limits of 0.4 and 0.3 ng l{sup -1} for cobalt and nickel were obtained, respectively. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.

  18. Application of Graphene as a Sorbent for the Preconcentration and Determination of Trace Amounts of Copper in Urine Samples Prior to Flame Atomic Absorption Spectrometry

    The potential of graphene as solid-phase extraction adsorbent for the separation and preconcentration of copper (Cu) has been investigated. Cu could be adsorbed quantitatively on graphene in the pH range of 4.0-7.0, and then eluted completely with 2.0 mL of 2.0 mol L/sub -1/ HNO/sub 3/ solution at a flow rate of 2.0 mL/sub -1/. A new method using a microcolumn packed with graphene as the sorbent was developed for the preconcentration of trace amounts of Cu prior to their determination by flame atomic absorption spectrometry (FAAS). Several effective parameters on the extraction and complex formation were selected and optimised. Under optimum conditions, an enrichment factor of 150 was obtained. The calibration graph was linear in the concentration range of 10.0-180.0 microg L/sub -1/ with a detection limit of 0.27 microg L/sub -1/. The relative standard deviation for ten replicate measurements of 10.0 and 70.0 microg L/sub -1/ of Cu were 3.68% and 3.35%, respectively. The method has been applied for the determination of trace amount of Cu in urine samples with satisfactory results. (author)

  19. Separation and Preconcentration of Ag(1) in Aqueous Samples by Flotation as an Ion-Associate Using Iodide and Ferroin Followed the Determination by Flame Atomic Absorption Spectrometry

    A simple method for separation/preconcentration and determination of Ag (1) in aqueous samples is described. The method is based on formation of an ion-associate between Ag (1)-iodide complex and ferroin, which can be floated at the interface of the aqueous/n-heptane phases. The flotation process was carried out using 500-ml aliquot of the aqueous solution and the floated layer was dissolved in 5 ml of 1 M HNO3 containing methanol (50% v/v) as the solvent. The Ag (1) content was then determined by flame atomic absorption spectrometry (FAAS). The method so could be considered as an enrichment process, was achieved to a quantitative feature, when the pH of the solution was adjusted to 4 and the concentrations of iodide and ferroin were about 3.2x10-4 M and 6.25x10-5 M, respectively. The LOD and RSD (n=7) were obtained 1.0x10-8 M and 2.4%, respectively. It was found that a large number of cations and anions even at high considerably foreign ion/Ag(1) ratios were not interfered. The method was applied satisfactorily to recovery of Ag(I) from different aqueous samples

  20. Determination of arsenic in ores, concentrates and related materials by graphite-furnace atomic-absorption spectrometry after separation by xanthate extraction.

    M Donaldson, E

    1988-01-01

    A method for determining approximately 0.2 mug/g or more of arsenic in ores, concentrates and related materials is described. After sample decomposition arsenic(V) is reduced to arsenic(III) with titanium(III) and separated from iron, lead, zinc, copper, uranium, tin, antimony, bismuth and other elements by cyclohexane extraction of its xanthate complex from approximately 8-10M hydrochloric acid. After washing with 10M hydrochloric acid-2% thiourea solution to remove residual iron and co-extracted copper, followed by water to remove chloride, arsenic is stripped from the extract with 16M nitric acid and ultimately determined in a 2% nitric acid medium by graphite-furnace atomic-absorption spectrometry, at 193.7 nm, in the presence of thiourea (which eliminates interference from sulphate) and palladium as matrix modifiers. Small amounts of gold, platinum and palladium, which are partly co-extracted as xanthates under the proposed conditions, do not interfere. PMID:18964463

  1. Immersed single-drop microextraction interfaced with sequential injection analysis for determination of Cr(VI) in natural waters by electrothermal-atomic absorption spectrometry

    Single-drop microextraction (SDME) and sequential injection analysis have been hyphenated for ultratrace metal determination by Electrothermal-Atomic Absorption Spectrometry (ETAAS). The novel method was targeted on extraction of the Cr(VI)-APDC chelate and encompasses the potential of SDME as a miniaturized and virtually solvent-free preconcentration technique, the ability of sequential injection analysis to handle samples and the versatility of furnace autosamplers for introducing microliter samples in ETAAS. The variables influencing the microextraction of Cr(VI) onto an organic solvent drop, i.e., type of organic solvent, microextraction time, stirring rate of the sample solution, drop volume, immersion depth of the drop, salting-out effect, temperature of the sample, concentration of the complexing agent and pH of the sample solution were fully investigated. For a 5 and 20 min microextraction time, the preconcentration factors were 20 and 70, respectively. The detection limit was 0.02 μg/L of Cr(VI) and the repeatability expressed as relative standard deviation was 7%. The SDME-SIA-ETAAS technique was validated against BCR CRM 544 (lyophilized solution) and applied to ultrasensitive determination of Cr(VI) in natural waters

  2. Investigation of chemical modifiers for sulfur determination in diesel fuel samples by high-resolution continuum source graphite furnace molecular absorption spectrometry using direct analysis

    Huber, Charles S. [Instituto Federal Sul-rio-grandense, Câmpus Pelotas, Pelotas, RS (Brazil); Universidade Federal do Rio Grande do Sul, Instituto de Química, Porto Alegre, RS (Brazil); Vale, Maria Goreti R. [Universidade Federal do Rio Grande do Sul, Instituto de Química, Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Universidade Federal de Santa Catarina, Departamento de Química, Florianópolis, SC (Brazil); Andrade, Jailson B. [Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Dessuy, Morgana B., E-mail: mbdessuy@ufrgs.br [Universidade Federal do Rio Grande do Sul, Instituto de Química, Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil)

    2015-06-01

    High-resolution continuum source graphite furnace molecular absorption spectrometry has been applied for sulfur determination in diesel fuel. The sharp rotational lines of the carbon monosulfide molecule (formed during the vaporization step) were used to measure the absorbance. The analytical line at 258.056 nm was monitored using the sum of three pixels. Different chemical modifiers were investigated and the mixture of palladium and magnesium was used as chemical modifier in combination with iridium as permanent modifier. L-Cysteine was chosen as sulfur standard and the calibration was done against aqueous standard solutions. The proposed method was applied for the analyses of four diesel samples: two S10 samples and two S500 samples. The trueness of the method was checked with a certified reference material (CRM) of sulfur in diesel fuel (NIST 2724b). Accurate results, for samples and CRM, were achieved after a dilution with propan-1-ol. The following figures of merit were obtained: characteristic mass of 17 ± 3 ng, limit of detection and limit of quantification of 1.4 mg kg{sup −1} and 4.7 mg kg{sup −1}, respectively. - Highlights: • Ir, Ru and Zr were investigated as permanent modifiers. • Ca, Mg, Pd and Pd/Mg were investigated as modifiers in solution. • Indirect determination of sulfur monitoring the molecular absorbance of the CS • Direct analysis of diesel samples using a dilution in propan-1-ol.

  3. A simple and fast procedure for the determination of Al, Cu, Fe and Mn in biodiesel using high-resolution continuum source electrothermal atomic absorption spectrometry

    A procedure for the determination of Al, Cu, Fe and Mn in biodiesel samples by high resolution continuum source electrothermal atomic absorption spectrometry is proposed. Sample preparation consists in simply diluting the biodiesel samples with ethanol at room temperature. For Al determination, a Zr-treated graphite tube was used as permanent modifier; for the other analytes no modifier was required. Calibration was carried out against aqueous standards, except for Al, for which calibration solutions were prepared using ethanol. Accuracy was verified by means of recovery tests and comparison with the results obtained using a different analytical procedure. The precision, expressed as the relative standard deviation, was typically better than 7%. Detection limits at ng g-1 levels for all analytes were obtained. The concentration of the analytes in biodiesel samples was generally very low, around a few tens of ng g-1, except for two samples for which the Fe concentrations were in the μg g-1 level. The proposed method has proved to be simple, precise and accurate.

  4. Investigation of chemical modifiers for sulfur determination in diesel fuel samples by high-resolution continuum source graphite furnace molecular absorption spectrometry using direct analysis

    High-resolution continuum source graphite furnace molecular absorption spectrometry has been applied for sulfur determination in diesel fuel. The sharp rotational lines of the carbon monosulfide molecule (formed during the vaporization step) were used to measure the absorbance. The analytical line at 258.056 nm was monitored using the sum of three pixels. Different chemical modifiers were investigated and the mixture of palladium and magnesium was used as chemical modifier in combination with iridium as permanent modifier. L-Cysteine was chosen as sulfur standard and the calibration was done against aqueous standard solutions. The proposed method was applied for the analyses of four diesel samples: two S10 samples and two S500 samples. The trueness of the method was checked with a certified reference material (CRM) of sulfur in diesel fuel (NIST 2724b). Accurate results, for samples and CRM, were achieved after a dilution with propan-1-ol. The following figures of merit were obtained: characteristic mass of 17 ± 3 ng, limit of detection and limit of quantification of 1.4 mg kg−1 and 4.7 mg kg−1, respectively. - Highlights: • Ir, Ru and Zr were investigated as permanent modifiers. • Ca, Mg, Pd and Pd/Mg were investigated as modifiers in solution. • Indirect determination of sulfur monitoring the molecular absorbance of the CS • Direct analysis of diesel samples using a dilution in propan-1-ol

  5. Preconcentrative separation of chromium(III) species from chromium(VI) by cloud point extraction and determination by flame atomic absorption spectrometry

    We describe a high-throughput technique for the determination of chromium species in water samples by flame atomic absorption spectrometry (FAAS) after preconcentrative separation of Cr(III) species from Cr(VI) by cloud point extraction (CPE) using diethyldithiocarbamate (DDTC) as the chelating agent and the nonionic surfactant Triton X-100 as the extractant. The Cr(III)-DDTC complex is extracted if the temperature is higher than the CPE temperature of Triton X-100, while Cr(VI) remains in the aqueous phase. The Cr(III) in the surfactant phase was analyzed by FAAS, and the concentration of Cr(VI) was calculated by subtraction of Cr(III) from total chromium which was directly determined by FAAS. The effect of pH, concentration of chelating agent, surfactant, and equilibration temperature were investigated. The detection limit for Cr(III) was 0. 08 μg L-1with an enrichment factor of 98, and the relative standard deviation was 1. 2% (n = 3, c = 100 μg L-1). A certified reference material and several water samples were analyzed with satisfactory results. (author)

  6. A dispersive liquid--liquid microextraction methodology for copper (II) in environmental samples prior to determination using microsample injection flame atomic absorption spectrometry.

    Alothman, Zeid A; Habila, Mohamed; Yilmaz, Erkan; Soylak, Mustafa

    2013-01-01

    A simple, environmentally friendly, and efficient dispersive liquid-liquid microextraction method combined with microsample injection flame atomic absorption spectrometry was developed for the separation and preconcentration of Cu(II). 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (5-Br-PADAP) was used to form a hydrophobic complex of Cu(II) ions in the aqueous phase before extraction. To extract the Cu(II)-5-Br-PADAP complex from the aqueous phase to the organic phase, 2.0 mL of acetone as a disperser solvent and 200 microL of chloroform as an extraction solvent were used. The influences of important analytical parameters, such as the pH, types and volumes of the extraction and disperser solvents, amount of chelating agent, sample volume, and matrix effects, on the microextraction procedure were evaluated and optimized. Using the optimal conditions, the LOD, LOQ, preconcentration factor, and RSD were determined to be 1.4 microg/L, 4.7 microg/L, 120, and 6.5%, respectively. The accuracy of the proposed method was investigated using standard addition/recovery tests. The analysis of certified reference materials produced satisfactory analytical results. The developed method was applied for the determination of Cu in real samples. PMID:24645524

  7. Ionic liquid-based single drop microextraction combined with electrothermal atomic absorption spectrometry for the determination of manganese in water samples.

    Manzoori, Jamshid L; Amjadi, Mohammad; Abulhassani, Jafar

    2009-02-15

    Room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C(4)MIM][PF(6)], was used as an alternative to volatile organic solvents in single drop microextraction-electrothermal atomic absorption spectrometry (SDME-ETAAS). Manganese was extracted from aqueous solution into a drop of the ionic liquid after complextaion with 1-(2-thiazolylazo)-2-naphthol (TAN) and the drop was directly injected into the graphite furnace. Several variables affecting microextraction efficiency and ETAAS signal, such as pyrolysis and atomization temperature, pH, TAN concentration, extraction time, drop volume and stirring rate were investigated and optimized. In the optimum experimental conditions, the limit of detection (3s) and the enhancement factor were 0.024 microg L(-1) and 30.3, respectively. The relative standard deviation (RSD) for five replicate determinations of 0.5 microg L(-1) Mn(II) was 5.5%. The developed method was validated by the analysis of a certified reference material (NIST SRM 1643e) and applied successfully to the determination of manganese in several natural water samples. PMID:19084676

  8. Separation/preconcentration and determination of vanadium with dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) and electrothermal atomic absorption spectrometry.

    Asadollahi, Tahereh; Dadfarnia, Shayessteh; Shabani, Ali Mohammad Haji

    2010-06-30

    A novel dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) for separation/preconcentration of ultra trace amount of vanadium and its determination with the electrothermal atomic absorption spectrometry (ETAAS) was developed. The DLLME-SFO behavior of vanadium (V) using N-benzoyl-N-phenylhydroxylamine (BPHA) as complexing agent was systematically investigated. The factors influencing the complex formation and extraction by DLLME-SFO method were optimized. Under the optimized conditions: 100 microL, 200 microL and 25 mL of extraction solvent (1-undecanol), disperser solvent (acetone) and sample volume, respectively, an enrichment factor of 184, a detection limit (based on 3S(b)/m) of 7 ng L(-1) and a relative standard deviation of 4.6% (at 500 ng L(-1)) were obtained. The calibration graph using the preconcentration system for vanadium was linear from 20 to 1000 ng L(-1) with a correlation coefficient of 0.9996. The method was successfully applied for the determination of vanadium in water and parsley. PMID:20685458

  9. Determination of lead and cadmium using an ionic liquid and dispersive liquid-liquid microextraction followed by electrothermal atomic absorption spectrometry.

    López-García, Ignacio; Vicente-Martínez, Yesica; Hernández-Córdoba, Manuel

    2013-06-15

    A procedure for the determination of ultratrace levels of lead and cadmium using dispersive liquid-liquid microextraction followed by electrothermal atomic absorption spectrometry (ETAAS) has been developed. The ionic liquid, 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C8MIm][NTf2]), is formed in situ and used to extract the lead and cadmium complexes with ammonium pyrrolidinedithiocarbamate. The very fine droplets of ([C8MIm][NTf2]) allow effective dispersion without the need for organic solvents. After centrifugation, the concentrations of lead and cadmium in the sedimented phase can be determined by ETAAS. Using a 10 mL aqueous sample, the enrichment factor of the procedure was 280 and detection limits of 0.2 and 3 ng L(-1) were obtained for cadmium and lead, respectively. The relative standard deviations for 10 replicates at the 10 ng L(-1) cadmium and 0.2 μg L(-1) lead levels were 6.5 and 7.3%, respectively. The method was successfully applied to the analysis of waters as well as to lixiviates obtained from toys made of plastic materials. PMID:23618174

  10. Solidified floating organic drop microextraction (SFODME) for simultaneous separation/preconcentration and determination of cobalt and nickel by graphite furnace atomic absorption spectrometry (GFAAS).

    Bidabadi, Mahboubeh Shirani; Dadfarnia, Shayessteh; Shabani, Ali Mohammad Haji

    2009-07-15

    Solidified floating organic drop microextraction (SFODME), combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for simultaneous separation/enrichment and determination of trace amounts of nickel and cobalt in surface waters and sea water. 1-(2-Pyridylazo)-2-naphthol (PAN) was used as chelating agent. The main parameters affecting the performance of SFODME, such as pH, concentration of PAN, extraction time, stirring rate, extraction temperature, sample volume and nature of the solvent were optimized. Under the optimum experimental conditions, a good relative standard deviation for six determination of 20 ng l(-1) of Co(II) and Ni(II) were 4.6 and 3.6%, respectively. An enrichment factor of 502 and 497 and detection limits of 0.4 and 0.3 ng l(-1) for cobalt and nickel were obtained, respectively. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments. PMID:19117672

  11. Different platform and tube geometries and atomization temperatures in graphite furnace atomic absorption spectrometry: Cadmium determination in whole blood as a case study

    In the present work the performance of different platform and tube geometries and atomization temperatures in graphite furnace atomic absorption spectrometry was investigated, using the determination of Cd in whole blood as an example. Grooved, integrated and fork platforms as well as atomization temperatures between 1200 deg. C and 2200 deg. C were investigated in a longitudinally heated graphite atomizer and compared with the performance of a transversely heated furnace. In the longitudinally heated furnace the increase of the atomization temperature in the studied range resulted in an increase of matrix effects for all platform geometries. The integrated platform exhibited slightly lower sensitivity and increased multiplicative interferences in comparison to the other two platform designs. Interference-free Cd determination was possible with all types of platforms and 1200 deg. C as the atomization temperature as well as with grooved and fork platforms at 1700 deg. C. On the other hand, lower atomization temperatures resulted in poorer limits of detection, due to the longer integration time needed. No matrix effect was observed at any atomization temperature using the transversely heated atomizer; in addition, limits of detection were better than those observed with the longitudinally heated atomizer. Best values were around 0.02 μg L-1 with the latter atomizer compared to values around 0.02 μg L-1 with the former one

  12. Multi-element determination of Cu, Fe, Ni and Zn content in vegetable oils samples by high-resolution continuum source atomic absorption spectrometry and microemulsion sample preparation.

    Nunes, Luana S; Barbosa, José T P; Fernandes, Andréa P; Lemos, Valfredo A; Santos, Walter N L Dos; Korn, Maria Graças A; Teixeira, Leonardo S G

    2011-07-15

    The aim of this work was to evaluate the microemulsification as sample preparation procedure for determination of Cu, Fe, Ni and Zn in vegetable oils samples by High-Resolution Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS). Microemulsions were prepared by mixing samples with propan-1-ol and aqueous acid solution, which allowed the use of inorganic aqueous standards for the calibration. To a sample mass of 0.5g, 100μL of hydrochloric acid and propan-1-ol were added and the resulting mixture diluted to a final volume of 10mL. The sample was manually shaken resulting in a visually homogeneous system. The main lines were selected for all studied metals and the detection limits (3σ, n=10) were 0.12, 0.62, 0.58 and 0.12mgkg(-1) for Cu, Fe, Ni and Zn, respectively. The relative standard deviation (RSD) ranged from 5% to 11 % in samples spiked with 0.25 and 1.5μgmL(-1) of each metal, respectively. Recoveries varied from 89% to 102%. The proposed method was applied to the determination of Cu, Fe, Ni and Zn in soybean, olive and sunflower oils. PMID:23140735

  13. Synthesis, characterization and application of a new chelating resin for solid phase extraction, preconcentration and determination of trace metals in some dairy samples by flame atomic absorption spectrometry.

    Daşbaşı, Teslima; Saçmacı, Şerife; Çankaya, Nevin; Soykan, Cengiz

    2016-11-15

    In this study, a simple and rapid solid phase extraction/preconcentration procedure was developed for determination of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Pb(II), and Zn(II) trace metals by flame atomic absorption spectrometry (FAAS). A new chelating resin, poly(N-cyclohexylacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid) (NCA-co-DVB-co-AMPS) (hereafter CDAP) was synthesized and characterized. The influences of the analytical parameters such as pH of the sample solution, type and concentration of eluent, flow rates of the sample and eluent, volume of the sample and eluent, amount of chelating resin, and interference of ions were examined. The limit of detection (LOD) of analytes were found (3s) to be in the range of 0.65-1.90μgL(-1). Preconcentration factor (PF) of 200 and the relative standard deviation (RSD) of ⩽2% were achieved (n=11). The developed method was applied for determination of analytes in some dairy samples and certified reference materials. PMID:27283608

  14. Determination of copper and mercury in phosphate fertilizers employing direct solid sampling analysis and high resolution continuum source graphite furnace atomic absorption spectrometry

    de Oliveira Souza, Sidnei; François, Luciane Luiza; Borges, Aline Rocha; Vale, Maria Goreti Rodrigues; Araujo, Rennan Geovanny Oliveira

    2015-12-01

    The present study proposes the determination of copper and mercury in phosphate fertilizers by direct solid sampling analysis (SS) employing high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). For Cu determination, two analytical lines were used: 327.3960 nm and 249.2146 nm. Hg determination was carried out on the line 253.6521 nm and 100 μg KMnO4 was used as chemical modifier. The optimal pyrolysis temperature for Cu determination was 1300 °C. Atomization temperatures for Cu and Hg were 2400 and 1100 °C, respectively. External calibration with aqueous standard solutions was adopted for both elements. The limits of quantification (LoQs) and characteristic mass (m0) obtained for Cu determination were 0.4 μg g- 1 and 1.12 ng, respectively, on line 249.2146 nm, and 64 μg g- 1 and 25 pg on 327.3960 nm. For mercury, LoQ and m0 were 4.8 ng g- 1 and 39 pg, respectively. The accuracy of the proposed methods was confirmed by the analysis of standard reference material (SRM) of Trace Elements in Multi-Nutrient Fertilizer (SRM NIST 695). The precision expressed as relative standard deviation (RSD), was better than 8.2% for Hg and 7.7% for the Cu (n = 5), considered satisfactory for microanalysis in solid sample. Four fertilizer samples acquired in commercial establishments in the city of Salvador, Bahia, Brazil, were analyzed. The optimized analytical methods were simple, fast, accurate, precise and free of spectral interferences for the determination of Cu and Hg in phosphate fertilizer samples by SS-HR-CS GF AAS, avoiding the dissolution of the sample, the use of harmful reagents and the generation of residues.

  15. Ultrasound-assisted single-drop microextraction for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry

    Almeida, Jorge S.; Anunciação, Taiana A. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Brandão, Geovani C. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); INCT de Energia e Ambiente, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Dantas, Alailson F. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Lemos, Valfredo A. [Laboratório de Química Analítica (LQA), Universidade Estadual do Sudoeste da Bahia, Campus de Jequié, Jequié, Bahia 45506-191 (Brazil); and others

    2015-05-01

    This work presents an ultrasound-assisted single-drop microextraction procedure for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry. Some initial tests showed that the best extraction efficiency was obtained when using ultrasound instead of mechanical agitation, indicating that acoustic cavitation improved the extraction process. Nitric, hydrochloric and acetic acids were evaluated for use in the extraction process, and HNO{sub 3} gave the best results. A two-level full-factorial design was applied to investigate the best conditions for the extraction of Cd from the oil samples. The influences of the sonication amplitude, time and temperature of the extraction were evaluated. The results of the design revealed that all of the variables had a significant effect on the experimental results. Afterward, a Box–Behnken design was applied to determine the optimum conditions for the determination of cadmium in vegetable oil samples. According to a multivariate study, the optimum conditions were as follows: sonication amplitude of 60%, extraction time of 15 min, extraction temperature of 46 °C and 0.1 mol L{sup −1} HNO{sub 3} as the extractor solution. Under optimized conditions, the developed method allows for the determination of Cd in oil samples with a limit of quantification of 7.0 ng kg{sup −1}. Addition and recovery experiments were performed in vegetable oil samples to evaluate the accuracy of the method, and the recoveries obtained varied from 90% to 115%. The samples were also analyzed after the acid digestion procedure, and the paired t-test (95% confidence level) did not show significant differences from the proposed method. - Highlights: • The determination of cadmium in vegetable oils was developed using UA-SDME. • HR-CS ET-AAS was employed as a detection technique with direct drop sampling. • The procedure allowed for a reduction in the consumption of reagents and

  16. Ultrasound-assisted single-drop microextraction for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry

    This work presents an ultrasound-assisted single-drop microextraction procedure for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry. Some initial tests showed that the best extraction efficiency was obtained when using ultrasound instead of mechanical agitation, indicating that acoustic cavitation improved the extraction process. Nitric, hydrochloric and acetic acids were evaluated for use in the extraction process, and HNO3 gave the best results. A two-level full-factorial design was applied to investigate the best conditions for the extraction of Cd from the oil samples. The influences of the sonication amplitude, time and temperature of the extraction were evaluated. The results of the design revealed that all of the variables had a significant effect on the experimental results. Afterward, a Box–Behnken design was applied to determine the optimum conditions for the determination of cadmium in vegetable oil samples. According to a multivariate study, the optimum conditions were as follows: sonication amplitude of 60%, extraction time of 15 min, extraction temperature of 46 °C and 0.1 mol L−1 HNO3 as the extractor solution. Under optimized conditions, the developed method allows for the determination of Cd in oil samples with a limit of quantification of 7.0 ng kg−1. Addition and recovery experiments were performed in vegetable oil samples to evaluate the accuracy of the method, and the recoveries obtained varied from 90% to 115%. The samples were also analyzed after the acid digestion procedure, and the paired t-test (95% confidence level) did not show significant differences from the proposed method. - Highlights: • The determination of cadmium in vegetable oils was developed using UA-SDME. • HR-CS ET-AAS was employed as a detection technique with direct drop sampling. • The procedure allowed for a reduction in the consumption of reagents and samples

  17. Determination of selenium in biological materials by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS)

    Galgan, Vera

    2007-01-01

    The selenium (Se) poor environment in the Scandinavian countries focused the interest on the development of an analytical method with high capacity, sensitivity, low limit of detection, including automated wet digestion, automated analysis and computer aided calculation. To facilitate the choice of an appropriate analytical method, procedures for determination in biological materials were discussed. The most frequently used sample-preparation procedures and various analytical techniques were ...

  18. Study of parameters associated with the determination of cadmium in lake sediments by slurry sampling electrothermal atomic absorption spectrometry

    Cadmium concentration in lake sediments is determined by suspending the solid samples in a solution containing 5% (v/v) concentrated nitric acid and 0.1% (v/v) Triton X-100. Three modifiers were tested for the direct determination. The furnace temperature programmes and appropriate amount for each modifier were optimised to get the highest signal and the best separation between the atomic and background signals. The drying stage is performed by programming a 400 deg. C temperature, a ramp time of 25 s and hold time of 10 s on the power supply of the atomiser. No ashing step is used and platform atomisation is carried out at 2200 deg. C. W-Rh permanent modifier combined with conventional modifier by delivering 10 μl of 0.50% (w/v) NH4H2PO4 solution was the best chemical modifier for cadmium determination. This modifier also acts as a liquid medium for the slurry, thus simplifying the procedure. Calibration is performed using aqueous standards in the 1-5 μg l-1 range. The optimised method gave a limit of detection of 0.56 ng ml-1, characteristic mass of 10.1±0.8 pg for aqueous standard, 9.6±0.7 pg for slurry samples containing different Cd concentrations and good precision (7.6-5.2%). The method was validated by analysing four certified reference lake sediment materials: LKSD-1, LKSD-2, LKSD-3 and LKSD-4; satisfactory recoveries were obtained (90.0-96.3%) and no statistical differences were observed between the experimental and the certified cadmium concentration. The developed methodology was used to determine cadmium in three 'real' sediment samples from lakes in the area of Wielkopolski National Park, Poland

  19. Lead determinations in human bone by particle induced x-ray emission (PIXE) and graphite furnace atomic absorption spectrometry (GFAAS)

    Chronic lead (Pb) intoxication has been linked to Alzheimer's disease (AD). Lead, like many heavy elements, tends to accumulate in bone. Pixe is a powerful analytical tool which permits the determination of Pb at the μg/g level without requiring sample digestion. GFAAS is one of the most sensitive methods for the determination of Pb and is capable of determining ng/g levels is solution. For bone analyses by GFAAS, sample dissolution and a matrix modifier are required. Rib bone samples were analyzed for Pb by PIXE and GFAAS. IAEA Animal Bone (H-5) was used as a secondary standard for Pb with both methods to ensure accuracy. The range of Pb concentrations in human rib bone was 1.4-11.5 μ/g for the trabecular surface by PIXE, 1.3-45 μg/g for the cortical surface by PIXE, and 1.54-11.75 μg/g for whole bone by GFAAS. No significant difference (p.<0.05 was found for AD versus control for either surface or for whole bone. (author). 17 refs., 2 figs., 3 tabs

  20. Fast sequential multi-element determination of major and minor elements in environmental samples and drinking waters by high-resolution continuum source flame atomic absorption spectrometry

    Highlights: • We develop a HR CS FAAS method for fast sequential multi-elemental analysis. • Major and minor elements are determined in a single run using the same solution. • Less than 10 mL of sample are necessary to determine in triplicate eleven elements. • The method is successfully applied in environmental samples and drinking waters. • The sample consumption is minimal compared to multi-elemental analysis by LS FAAS. - Abstract: The fast sequential multi-element determination of 11 elements present at different concentration levels in environmental samples and drinking waters has been investigated using high-resolution continuum source flame atomic absorption spectrometry. The main lines for Cu (324.754 nm), Zn (213.857 nm), Cd (228.802 nm), Ni (232.003 nm) and Pb (217.001 nm), main and secondary absorption lines for Mn (279.482 and 279.827 nm), Fe (248.327, 248.514 and 302.064 nm) and Ca (422.673 and 239.856 nm), secondary lines with different sensitivities for Na (589.592 and 330.237 nm) and K (769.897 and 404.414 nm) and a secondary line for Mg (202.582 nm) have been chosen to perform the analysis. A flow injection system has been used for sample introduction so sample consumption has been reduced up to less than 1 mL per element, measured in triplicate. Furthermore, the use of multiplets for Fe and the side pixel registration approach for Mg have been studied in order to reduce sensitivity and extend the linear working range. The figures of merit have been calculated and the proposed method was applied to determine these elements in a pine needles reference material (SRM 1575a), drinking and natural waters and soil extracts. Recoveries of analytes added at different concentration levels to water samples and extracts of soils were within 88–115% interval. In this way, the fast sequential multi-element determination of major and minor elements can be carried out, in triplicate, with successful results without requiring additional dilutions of

  1. The use of microemulsion for determination of sodium and potassium in biodiesel by flame atomic absorption spectrometry.

    de Jesus, Alexandre; Silva, Márcia M; Vale, Maria Goreti R

    2008-02-15

    A new method for F AAS determination of sodium and potassium in biodiesel using water-in-oil microemulsion as sample preparation is proposed. The method was investigated for biodiesel produced from different sources, as soybean, castor and sunflower oil and animal fat and was also applied for vegetable oils. The optimized condition for microemulsion formation was 57.6% (w/w) of n-pentanol, 20% (w/w) of biodiesel or vegetable oil, 14.4% (w/w) of Triton X-100 and 8% (w/w) of water (aqueous standard of KCl or NaCl in/or diluted HNO(3)). The optimized instrumental parameters were: aspiration rate of 2 mL min(-1) and the flame composition of 0.131 of C(2)H(2)/air ratio. For comparison purpose, the determination of sodium and potassium were also carried out according to European norms (EN 14108 and EN 14109, respectively). These norms are applied for determination of sodium and potassium in fatty acid methylic ester samples and consist in the sample dilution using organic solvent and determination by F AAS. The stability of microemulsified aqueous standards and samples was investigated and it was found to be stable for at least 3 days while the organic standard diluted with xylene showed a decrease around of 15% in the analytical signal in 1h. The limits of detection were 0.1 microg g(-1) and 0.06 microg g(-1) and the obtained characteristic concentrations were 25 microg L(-1) and 28 microg L(-1) for sodium and potassium, respectively. The proposed method presented two times better limits of detection and better precision (0.4-1.0%) when compared with the dilution technique (1.5-4.5%). The accuracy of the method was evaluated through recovery tests and comparison with the results obtained by dilution technique. The recoveries ranged from 95% to 115% for biodiesel and 90% to 115% for vegetable oil samples. Comparison between the results obtained for biodiesel by both methods showed no significant differences at the 95% confidence level according to a Student's t

  2. Graphene-based solid-phase extraction combined with flame atomic absorption spectrometry for a sensitive determination of trace amounts of lead in environmental water and vegetable samples.

    Wang, Yukun; Gao, Shutao; Zang, Xiaohuan; Li, Jingci; Ma, Jingjun

    2012-02-24

    Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with graphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) using dithizone as chelating reagent prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 10.0-600.0 μg L(-1) with a detection limit of 0.61 μg L(-1). The relative standard deviation for ten replicate measurements of 20.0 and 400.0 μg L(-1) of Pb were 3.56 and 3.25%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Pb. The proposed method was successfully applied in the analysis of environmental water and vegetable samples. Good spiked recoveries over the range of 95.3-100.4% were obtained. This work not only proposes a useful method for sample preconcentration, but also reveals the great potential of graphene as an excellent sorbent material in analytical processes. PMID:22284885

  3. Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

    Virgilio, Alex; Nobrega, Joaquim A. [Department of Chemistry, Federal University of Sao Carlos, Post Office Box 676, 13560-970, Sao Carlos-SP (Brazil); Rego, Jardes F. [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil); Neto, Jose A. Gomes, E-mail: anchieta@iq.unesp.br [Department of Analytical Chemistry, Institute of Chemistry, Sao Paulo State University-UNESP, Post Office Box 355, 14801-970, Araraquara-SP (Brazil)

    2012-12-01

    A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 Degree-Sign C and 2400 Degree-Sign C, respectively. Slopes of calibration curves (50-750 pg Cr, R{sup 2} > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3-17.7 {mu}g g{sup -1} Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 {+-} 2.1 {mu}g g{sup -1} Cr. The limit of detection was 3.3 ng g{sup -1} Cr. - Highlights: Black-Right-Pointing-Pointer Direct solid sampling is first time employed for Cr in plant materials. Black-Right-Pointing-Pointer Calibration curves with liquids and solids are coincident. Black-Right-Pointing-Pointer Microanalysis of plants for Cr is validated by reference materials. Black-Right-Pointing-Pointer The proposed HR-CS GF AAS method is environmental friendly.

  4. Evaluation of solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry for direct determination of chromium in medicinal plants

    Virgilio, Alex; Nóbrega, Joaquim A.; Rêgo, Jardes F.; Neto, José A. Gomes

    2012-12-01

    A method for Cr determination in medicinal plants using direct solid sampling graphite furnace high-resolution continuum source atomic absorption spectrometry was developed. Modifiers were dispensable. Pyrolysis and atomization temperatures were 1500 °C and 2400 °C, respectively. Slopes of calibration curves (50-750 pg Cr, R2 > 0.999) using aqueous and solid standards coincides in 96%, indicated feasibility of aqueous calibration for solid sampling of medicinal plants. Accuracy was checked by analysis of four plant certified reference materials. Results were in agreement at 95% confidence level with certified and non-certified values. Ten samples of medicinal plants were analyzed and Cr contents were in the 1.3-17.7 μg g- 1 Cr range. The highest RSD (n = 5) was 15.4% for the sample Melissa officinalis containing 13.9 ± 2.1 μg g- 1 Cr. The limit of detection was 3.3 ng g- 1 Cr.

  5. Homogeneous liquid-liquid extraction for preconcentration and trace determination of lead in drinking water, distilled spirit and wine by flame atomic absorption spectrometry

    Complete text of publication follows. Trace amount of lead at ng/mL level was preconcentrated by using homogeneous liquid-liquid extraction method of lead diethyldithiocarbamate (Pb-DDTC) complex with perfluorooctanoate ion (PFOA-) dissolved in lithium hydroxide under acidic conditions. The effects of type and concentration of acid solution, amount of DDTC, pH of the sample solution, type and volume of organic solvent, and concentration of PFOA- on the extraction method of Pb(II) were investigated in detail. Under the optimized conditions (0.01M DDTC, 2.5 x 10-2M PFOA-, 8.0M HCl), 5 μg of Pb(II) in 60 mL aqueous phase could be extracted quantitatively into 100 μL sedimented phase. The sedimented phase dissolved in 3 mL of 1%(v/v) HNO3 was then subjected into a conventional measurement of flame atomic absorption spectrometry (FAAS). The enrichment factor of 20-fold for this method was obtained. The proposed method was applied to the extraction and determination of Pb(II) in drinking water, distilled spirit and wine samples.

  6. Magnetic stirrer induced dispersive ionic-liquid microextraction for the determination of vanadium in water and food samples prior to graphite furnace atomic absorption spectrometry.

    Naeemullah; Kazi, Tasneem Gul; Tuzen, Mustafa

    2015-04-01

    A new dispersive liquid-liquid microextraction, magnetic stirrer induced dispersive ionic-liquid microextraction (MS-IL-DLLME) was developed to quantify the trace level of vanadium in real water and food samples by graphite furnace atomic absorption spectrometry (GFAAS). In this extraction method magnetic stirrer was applied to obtained a dispersive medium of 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6] in aqueous solution of (real water samples and digested food samples) to increase phase transfer ratio, which significantly enhance the recovery of vanadium - 4-(2-pyridylazo) resorcinol (PAR) chelate. Variables having vital role on desired microextraction methods were optimised to obtain the maximum recovery of study analyte. Under the optimised experimental variables, enhancement factor (EF) and limit of detection (LOD) were achieved to be 125 and 18 ng L(-1), respectively. Validity and accuracy of the desired method was checked by analysis of certified reference materials (SLRS-4 Riverine water and NIST SRM 1515 Apple leaves). The relative standard deviation (RSD) for 10 replicate determinations at 0.5 μg L(-1) of vanadium level was found to be <5.0%. This method was successfully applied to real water and acid digested food samples. PMID:25442538

  7. Direct determination of selenium in whole blood by electrothermal atomic absorption spectrometry using W Rh-coated platform and co-injection of Rh as thermal stabilizer

    Zanão, Renato A.; Barbosa, Fernando, Jr.; Souza, Samuel S.; Krug, Francisco J.; Abdalla, Adibe L.

    2002-02-01

    A W-Rh coating on the integrated platform of a transversely heated graphite atomizer (platform modifier) and a RhCl 3 solution (analyte/matrix modifier) were combined for the direct determination of selenium in whole blood by electrothermal atomic absorption spectrometry. Samples were diluted 1+4 v/v with a mixture of 0.2% v/v HNO 3 and 0.5% v/v Triton X-100. For the analysis, 12 μl of the resulting sample plus 6 μl of the Rh solution were delivered into the transversely heated graphite atomizer (THGA) platform modified with W-Rh. The combined use of Rh solution with the W-Rh coating was decisive in increasing the maximum pyrolysis temperature of blood selenium up to 1300 °C. Use of W-Rh as a platform modifier increased the tube useful lifetime up to 200% when compared to an untreated platform using a conventional [Pd+Mg(NO 3) 2] modifier. The accuracy and precision of the method proposed were verified by analyzing serum certified reference material (Seronorm™) and 20 whole blood samples using Pd/Mg(NO 3) 2 modifier in untreated platforms; no statistical differences were found between methods by applying the t-test at the 95% level.

  8. Simultaneous determination of Cr, Ni and V in urine by electrothermal atomic absorption spectrometry (ET AAS); Determinacion simultanea de Cr, Ni y V en orina mediante et aas

    Alvarez, Maria A.; Hermida, Jeymi [Universidad Central de Venezuela, Caracas (Venezuela, Bolivarian Republic of). Escuela de Quimica. Centro de Quimica Analitica

    2011-07-01

    A procedure for the simultaneous determination of Cr, Ni, and V in urine by electrothermal atomic absorption spectrometry (ET AAS) was optimized by factorial design, and performed at a pyrolysis and atomization temperatures of 1300 and 2500 deg C, respectively, using 15 {mu}g de Mg(NO{sub 3}){sub 2} as chemical modifier. Characteristics mass of 14, 6 and 220 {rho}g and detection limits of the method of 0.07, 0.38 and 0.75 {mu}g L{sup -1} were obtained for Cr, Ni and V respectively. The methodology was validated using a Liphochek Urine Metals Control sample (Bio-Rad) (P=0.05). The methodology was applied to samples of voluntary Venezuelan people, not environmentally exposed to specific emissions, and results ranging from < LOD-1.1 and 1.3-3.3 {mu}g L{sup -1} was observed for Cr and V, respectively, and not detectable levels for Ni. (author)

  9. Preconcentration, speciation and determination of ultra trace amounts of mercury by modified octadecyl silica membrane disk/electron beam irradiation and cold vapor atomic absorption spectrometry

    Ashkenani, Hamid [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Dadfarnia, Shayessteh [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of)], E-mail: sdadfarnia@yazduni.ac.ir; Shabani, Ali Mohammad Haji; Jaffari, Abbas Ali [Department of Chemistry, Yazd University, Yazd (Iran, Islamic Republic of); Behjat, Abbas [Department of physics, Yazd University, Yazd (Iran, Islamic Republic of)

    2009-01-15

    Mercury (II) and methyl mercury cations at the Sub-ppb level were adsorbed quantitatively from aqueous solution onto an octadecyl-bonded silica membrane disk modified by 2-[(2-mercaptophyenylimino)methyl] phenol (MPMP). The trapped mercury was then eluted with 3 ml ethanol and Hg{sup 2+} ion was directly measured by cold vapor atomic absorption spectrometry, utilizing tin (II) chloride. Total mercury (Hgt) was determined after conversion of MeHg{sup +} into Hg{sup 2+} ion by electron beam irradiation. A sample volume of 1500 ml resulted in a preconcentration factor of 500 and the precision for a sampling volume of 500 ml at a concentration of 2.5 {mu}g l{sup -1} (n = 7) was 3.1%. The limit of detection of the proposed method is 3.8 ng l{sup -1}. The method was successfully applied to analysis of water samples, and the accuracy was assessed via recovery experiment.

  10. Solid-phase Extraction on Magnetic Multi-walled Carbon Nanotubes Coupled with Flame Atomic Absorption Spectrometry for Determining Lead and Cadmium in Traditional Chinese Medicine

    In this study, magnetic carbon nanotubes (MCNTs) were prepared by mixing the magnetic particles and multi-walled carbon nanotubes in dispersed solutions. These MCNTs were used as adsorbents of magnetic solid-phase extraction (MSPE). By coupling MSPE with flame atomic absorption spectrometry, a rapid and sensitive method for analyzing lead and cadmium using ammonium pyrrolidine dithiocarbamate as chelating reagent was established. Under optimal conditions, calibration graphs were linear in the range of 10.0-400.0 μ g L /sup-1/ and 10.0-300.0 μ g L /sup -1/ with detection limit of 0.6 μ g L /sup -1/ and 0.5 μ g L /sup -1/ for Pb and Cd, respectively. A good relative standard deviation for determining 300.0 μ g L-1 of Pb and Cd were 3.8 and 3.4 percentage, respectively. The proposed method was applied to analyze several traditional Chinese medicine samples with satisfactory results. (author)

  11. Sensitive determination of bismuth by flame atomic absorption spectrometry using atom trapping in a slotted quartz tube and revolatilization with organic solvent pulse

    Sensitivity of flame atomic absorption spectrometry (FAAS) for Bi determination was improved by slotted quartz tube (SQT) that was used also for atom trapping (AT). The trapped analyte was released by aspirating a small volume of organic solvent after a reasonable analyte collection time. Sensitivity was improved by 2.9 times by SQT-FAAS and 256 times by SQT-AT-FAAS with respect to FAAS. Optimum trapping period was found to be 6.0 min (36.0 mL of solution). Limit of detection (LOD) for SQT-AT-FAAS was found to be 1.6 ng mL−1. %RSD was calculated as 4.0% for five replicate measurements of 7.5 ng mL−1 Bi by SQT-AT-FAAS. Accuracy of the method developed was checked by analyzing a standard reference material of simulated fresh water (NIST 1643e) and result found was in good agreement with the certified one. The method can be applied in any laboratory equipped with a flame AA spectrometer. The consumption of time and sample volume is fairly low and application is simple and easy.

  12. Investigation of chemical modifiers for sulfur determination in diesel fuel samples by high-resolution continuum source graphite furnace molecular absorption spectrometry using direct analysis

    Huber, Charles S.; Vale, Maria Goreti R.; Welz, Bernhard; Andrade, Jailson B.; Dessuy, Morgana B.

    2015-06-01

    High-resolution continuum source graphite furnace molecular absorption spectrometry has been applied for sulfur determination in diesel fuel. The sharp rotational lines of the carbon monosulfide molecule (formed during the vaporization step) were used to measure the absorbance. The analytical line at 258.056 nm was monitored using the sum of three pixels. Different chemical modifiers were investigated and the mixture of palladium and magnesium was used as chemical modifier in combination with iridium as permanent modifier. L-Cysteine was chosen as sulfur standard and the calibration was done against aqueous standard solutions. The proposed method was applied for the analyses of four diesel samples: two S10 samples and two S500 samples. The trueness of the method was checked with a certified reference material (CRM) of sulfur in diesel fuel (NIST 2724b). Accurate results, for samples and CRM, were achieved after a dilution with propan-1-ol. The following figures of merit were obtained: characteristic mass of 17 ± 3 ng, limit of detection and limit of quantification of 1.4 mg kg- 1 and 4.7 mg kg- 1, respectively.

  13. Photoassisted vapor generation in the presence of organic acids for ultrasensitive determination of Se by electrothermal-atomic absorption spectrometry following headspace single-drop microextraction

    A method is described for the determination of selenium at the pg/mL level by electrothermal-atomic absorption spectrometry using in situ photogeneration of Se vapors, headspace sequestration onto an aqueous microdrop containing Pd(II) and subsequent injection in a graphite tube. Several organic acids (formic, oxalic, acetic, citric and ethylenediaminetetraacetic) have been tried for photoreduction of Se(IV) into volatile Se compounds under UV irradiation. Experimental variables such as UV irradiation time, organic acid concentration, Pd(II) concentration in the drop, sample and drop volumes, extraction time and pH were fully optimized. Low-molecular weight acids such as formic and acetic provided optimal photogeneration of volatile Se species at a 0.6 mol/L concentration. Citric and ethylenediaminetetraacetic acid allowed to use a concentration as low as 1 mmol/L, but extraction times were longer than for formic and acetic acids. Photogeneration of (CH3)2Se from Se(IV) in the presence of acetic acid provided a detection limit of 20 pg/mL, a preconcentration factor of nearly 285 and a precision, expressed as relative standard deviation, of 4%. Analytical performance seemed to depend not only on the photogeneration efficiency obtained with each acid but also on the stability of the vapors in the headspace. The method showed a high freedom from interferences caused by saline matrices, but interferences were observed for transition metals at a relatively low concentration

  14. Determination of sulfur in coal using direct solid sampling and high-resolution continuum source molecular absorption spectrometry of the CS molecule in a graphite furnace.

    Mior, Renata; Morés, Silvane; Welz, Bernhard; Carasek, Eduardo; de Andrade, Jailson B

    2013-03-15

    An analytical method has been developed for the determination of sulfur in coal using direct solid sample analysis in a graphite tube furnace and high-resolution continuum source molecular absorption spectrometry (HR-CS GF MAS). The molecular absorbance of the carbon monosulfide molecule (CS), which is formed in the vaporization stage, has been measured using the rotational line at 258.033 nm. Several chemical modifiers were tested and Ru, applied as permanent modifier was chosen, because it exhibited the best performance. The optimum pyrolysis and vaporization temperatures were found to be 500 °C and 2200 °C, respectively. Aqueous standard solutions prepared from l-cysteine were used for calibration, as the linear regression obtained for this standard was not significantly different from that for a certified coal reference material (CRM) according to a Student t-test. The results obtained for sulfur in three coal CRM and six additional samples also showed no significant difference for the two calibration techniques according to the same statistical test. The sulfur concentration in the coal samples was found between 3.5 mg g(-1) and 33.7 mg g(-1) with a typical repeatability around 10%. The limit of detection for the direct analysis of solid coal samples was better than 0.1 μg S. PMID:23598139

  15. A Novel Method Using Solid-Phase Extraction with Slotted Quartz Tube Atomic Absorption Spectrometry for the Determination of Manganese in Walnut Samples.

    Bitirmis, Bedrana; Trak, Digdem; Arslan, Yasin; Kendüzler, Erdal

    2016-01-01

    Mn(2+) was separated and preconcentrated using both solid-phase extraction (SPE) and a slotted quartz tube (SQT), and detected by a flame atomic absorption spectrometry (FAAS) system. Firstly, Mn(2+) was retained on a column filled with Amberlite CG-120 resin, and then retained Mn(2+) ions on the Amberlite CG-120 resin eluted with 5 mL of 4 mol/L HNO3. This part was called the "first preconcentration step". Furthermore, to determine the Mn(2+) in a walnut sample, the SQT device was also used after the separation and preconcentration of Mn(2+) from the Amberlite CG-120 resin so as to further improve the sensitivity of system. This part was called the "second preconcentration step" in this study. The enrichment factor and limit of detection values were found to be 360 fold and 0.22 μg/L, in turn, after a two-step preconcentration method. The good accuracy of method was confirmed with the use of standard reference material (spinach leaves, NIST-1570a). PMID:27302588

  16. Preconcentration and Determination of Copper(Ⅱ) Using Octadecyl Silica Membrane Disks Modified by 1,5-Diphenylcarhazide and Flame Atomic Absorption Spectrometry

    MOGHIMI Ali

    2007-01-01

    A simple and reproducible method for the rapid extraction and determination of trace amounts of copper(Ⅱ)ions using octadecyl-bonded silica membrane disks modified by 1,5-diphenylcarbazide (DPC) and atomic absorption spectrometry was presented, which was based on complex formation on the surface of the ENVI-18 DISKTM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effect of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to be about 1000 mL providing a preconcentration factor of 400. The maximum capacity of the disks was found to be (255±5) μg for Cu2+, and the limit of detection of the proposed method was 5 ng per 1000 mL. The method was applied to the extraction and recovery of copper in different water samples.

  17. Ultrasound-assisted emulsification microextraction based on solidification floating organic drop trace amounts of manganese prior to graphite furnace atomic absorption spectrometry determination.

    Mohadesi, Alireza; Falahnejad, Masoumeh

    2012-01-01

    In the present study, an ultrasound-assisted emulsification microextraction based on solidification floating organic drop method is described for preconcentration of trace amounts of Mn (II). 2-(5-Bromo-2-pyridylazo)-5 diethylaminophenol was added to a solution of Mn(+2) at ph = 10.0. After this, 1-undecanol was added to the solution as an extraction solvent, and solution was stirred. Several factors influencing the microextraction efficiency, such as pH, the amount of chelating agent, nature and volume of extraction solvent, the volume of sample solution, stirring rate, and extraction time were investigated and optimized. Then sample vial was cooled by inserting into an ice bath, and the solidified was transferred into a suitable vial for immediate melting. Finally the sample was injected into a graphite furnace atomic absorption spectrometry. Under the optimum condition the linear dynamic range was 0.50-10.0 ng mL(-1) with a correlation coefficient of 0.9926, and the detection limit of 0.3 ng mL(-1) was obtained. The enrichment factor was 160. The proposed method was successfully applied for separation and determination of manganese in sea, rain, tap, and river water samples. PMID:22645504

  18. Evaluation of two atomisation modes for direct determination of molybdenum in complex matrices by ultrasonic slurry sampling-electrothermal atomic absorption spectrometry

    Tube wall (TWA) and L'vov platform (LPA) atomisations were compared for the direct determination of molybdenum (Mo) in coal fly ash by slurry sampling-electrothermal atomic absorption spectrometry (ETAAS). For both atomisation modes eight chemical modifiers were tested, namely HNO3, Pd(NO3)2, Mg(NO3)2, Pd + Mg(NO3)2, reduced Pd, BaF2, Ir and HF. The interfering effects of major and minor concomitants of samples on Mo signals and memory effects were also evaluated. BaF2 and Pd(NO3)2 + Mg(NO3)2 mixture were selected for TWA and LPA, respectively. Standard addition calibration is needed in both cases. The best peak performance, memory effect reduction, within-run precision (6% versus 9% R.S.D.), and sensitivity (mo 7.5 pg versus 15.2 pg) were achieved with TWA compared to LPA. Both atomisation modes gave good analytical recoveries (94-102%), but the analysis of a certified coal fly ash (NIST SRM 1633a) only was accurate using TWA. Additionally, the urban dust NIST SRM 1629a was analysed

  19. Development of a simple method for the determination of lead in lipstick using alkaline solubilization and graphite furnace atomic absorption spectrometry.

    Soares, Aline Rodrigues; Nascentes, Clésia Cristina

    2013-02-15

    A simple method was developed for determining the total lead content in lipstick samples by graphite furnace atomic absorption spectrometry (GFAAS) after treatment with tetramethylammonium hydroxide (TMAH). Multivariate optimization was used to establish the optimal conditions of sample preparation. The graphite furnace heating program was optimized through pyrolysis and atomization curves. An aliquot containing approximately 50mg of the sample was mixed with TMAH and heated in a water bath at 60°C for 60 min. Using Nb as the permanent modifier and Pd as the chemical modifier, the optimal temperatures were 900°C and 1800°C for pyrolysis and atomization, respectively. Under optimum conditions, the working range was from 1.73 to 50.0 μg L(-1), with detection and quantification limits of 0.20 and 0.34 μg g(-1), respectively. The precision was evaluated under conditions of repeatability and intermediate precision and showed standard deviations of 2.37%-4.61% and 4.93%-9.75%, respectively. The % recovery ranged from 96.2% to 109%, and no significant differences were found between the results obtained using the proposed method and the microwave decomposition method for real samples. Lead was detected in 21 tested lipstick samples; the lead content in these samples ranged from 0.27 to 4.54 μg g(-1). PMID:23598019

  20. Accuracy of a method based on atomic absorption spectrometry to determine inorganic arsenic in food: Outcome of the collaborative trial IMEP-41.

    Fiamegkos, I; Cordeiro, F; Robouch, P; Vélez, D; Devesa, V; Raber, G; Sloth, J J; Rasmussen, R R; Llorente-Mirandes, T; Lopez-Sanchez, J F; Rubio, R; Cubadda, F; D'Amato, M; Feldmann, J; Raab, A; Emteborg, H; de la Calle, M B

    2016-12-15

    A collaborative trial was conducted to determine the performance characteristics of an analytical method for the quantification of inorganic arsenic (iAs) in food. The method is based on (i) solubilisation of the protein matrix with concentrated hydrochloric acid to denature proteins and allow the release of all arsenic species into solution, and (ii) subsequent extraction of the inorganic arsenic present in the acid medium using chloroform followed by back-extraction to acidic medium. The final detection and quantification is done by flow injection hydride generation atomic absorption spectrometry (FI-HG-AAS). The seven test items used in this exercise were reference materials covering a broad range of matrices: mussels, cabbage, seaweed (hijiki), fish protein, rice, wheat, mushrooms, with concentrations ranging from 0.074 to 7.55mgkg(-1). The relative standard deviation for repeatability (RSDr) ranged from 4.1 to 10.3%, while the relative standard deviation for reproducibility (RSDR) ranged from 6.1 to 22.8%. PMID:27451169

  1. Determination of the elemental composition of cyanobacteria cells and cell fractions by atomic emission and atomic absorption spectrometry

    An approach to studying the elemental composition of cyanobacteria Spirulina platensis and Nostoc commune using a set of complementary analytical methods (ICP-AES, PAAS, and ETAAS) was proposed . The procedures were adapted for the determination of macro- and microelements (Na, K, Mg, Ca, Fe, Mn, Cu, Mo, Zn, B, and Se) in the biomass of cyanobacteria and separated cell fractions (chloroform and water-methanol extracts and precipitates). The conditions for the mineralization of biological materials were optimized for autoclave and microwave sample preparation procedures. The evaporation and atomization of Se and Mo in a graphite furnace in the presence of chloroform and methanol were studied

  2. Solvent bar micro-extraction with graphite atomic absorption spectrometry for the determination of silver in ocean water.

    López-López, José A; Herce-Sesa, Belén; Moreno, Carlos

    2016-10-01

    Main drawbacks for silver determination in seawater are the effects of samples matrix and that Ag appears in the sub ng L(-1). Available methods for sample preparation in Ag analysis are based on solid and liquid extraction using tedious process that increase the cost of analysis and the risk of sample contamination, producing important waste amounts. Solvent bar micro-extraction (SBME) allows the pre-concentration of Ag in a micro-volume of the ionic liquid Aliquat 336® in kerosene solution. For this reason, it is considered as a green alternative to standard methods. The method has been optimized using synthetic seawater samples, offering the highest response for samples at pH=2, using 5% Aliquat 336® dissolved in kerosene containing 5% dodecan-1-ol as acceptor solution and after 1h stirring at 800rpm. The method exhibited linearity up to 50ngL(-1), with a limit of detection of 0.09ngL(-1), covering the concentration range of interest for environmental studies. Finally, it was applied for determination of Ag in real seawater samples, and the results were compared with the reference method of liquid-liquid extraction with 1-pyrrolidine-dithiocarbamate and diethylammonium-diethyldithiocarbamate, showing the applicability of ionic liquid based SBME using Aliquat 336(®) for the simple monitoring of silver ultra-traces in seawater analysis. PMID:27474287

  3. Electrochemical generation of arsenic volatile species using a gold/mercury amalgam cathode. Determination of arsenic by atomic absorption spectrometry

    Andrea Caiminagua

    2015-03-01

    Full Text Available The electrochemical generation of arsenic volatile species (arsine using an Au/Hg amalgam cathode in a 0.5 M H2SO4 solution, is described. Results were compared with those obtained with other cathodes commonly used for generation of arsine. The effects of the electrolytic conditions and interferent ions have been studied. Results show that the Au/Hg cathode has better tolerance to interference and higher repeatability than cathodes made out of platinum (Pt, gold (Au, reticulated glassy carbon (RGC, lead (Pb. Under optimized conditions, a 0.027 μg L−1 (3σ detection limit for As(III in aqueous solutions and a 2.4% relative standard deviation for a 0.1 μg L−1 As(III were obtained. The accuracy of the method was verified by determination of As in a certified reference material. The proposed method was applied to the determination of As in spiked tap water samples.

  4. Molecular absorption spectrometry in flames and furnaces: A review

    Graphical abstract: -- Highlights: •Theory and analytical considerations for molecular absorption spectrometry (MAS). •Critical review of low resolution MAS. •Critical review of the analytical performance of high-resolution continuum source (HR-CS) flame MAS. •Critical review of the analytical performance of HR-CS graphite furnace MAS. •Current status of HR-CS MAS and its future prospects for elemental analysis. -- Abstract: Molecular absorption spectrometry (MAS), originally developed in the 1970s, is a technique to determine non-metals in flames and graphite furnaces by monitoring the absorbance of diatomic molecules. Early studies employed low resolution instruments designed for line source atomic absorption, which provided a limited choice of analytical wavelengths, insufficient spectral resolution, and spectral interferences. However, the development of high-resolution continuum source atomic absorption spectrometry (HR-CS AAS) instrumentation has allowed the analysis of challenging samples for non-metals as well as some difficult elements to determine by AAS, such as aluminum and phosphorus. In this review, theory and analytical considerations for MAS are discussed. The principles and limitations of low resolution MAS are described, along with its applications. HR-CS AAS instrumentation is reviewed, emphasizing performance characteristics most relevant for MAS. Applications of flame and HR-CS GFMAS are reviewed, highlighting the most significant work to date. The paper concludes with an evaluation of the enhanced analytical capabilities provided by HR-CS MAS

  5. Determination of arsenic in diesel, gasoline and naphtha by graphite furnace atomic absorption spectrometry using microemulsion medium for sample stabilization

    Brandao, Geisamanda Pedrini; Campos, Reinaldo Calixto de [Pontifical Catholic University, Department of Chemistry, Rio de Janeiro, RJ (Brazil); Luna, Aderval Severino [Rio de Janeiro State University, Department of Analytical Chemistry, Rio de Janeiro, RJ (Brazil); Castro, Eustaquio Vinicius Ribeiro de; Jesus, Honerio Coutinho de [Espirito Santo Federal University, Department of Chemistry, Vitoria, ES (Brazil)

    2008-08-15

    A procedure for the determination of As in diesel, gasoline and naphtha at {mu}g L{sup -1} levels by GFAAS is proposed. Sample stabilization was achieved by the formation of three component solutions prepared by mixing appropriate volumes of the samples propan-1-ol and nitric acid aqueous solution. This mixture resulted in a one-phase medium, which was indefinitely stable. No changes in the analyte signals were observed over several days in spiked samples, proving long-term stabilization ability. The use of conventional (Pd) and permanent (Ir) modification was investigated and the former was preferred. Central composite design multivariate optimization defined the optimum microemulsion composition as well as the temperature program. In this way, calibration using aqueous analytical solutions was possible, since the same sensitivity was observed in the investigated microemulsion media and in 0.2% v/v HNO{sub 3}. Coefficients of correlation larger than 0.999 and an As characteristic mass of 22 pg were observed. Recoveries (n=4) obtained from spiked samples were 98{+-}4, 99{+-}3 and 103{+-}5%, and the limits of detection in the original samples were 1.8, 1.2 and 1.5 {mu}g L{sup -1} for diesel, gasoline and naphtha, respectively. Validation was performed by the analysis of a set of commercial samples by independent comparative procedures. No significant difference (Student's t-test, p<0.05) was observed between comparative and proposed procedure results. The total determination cycle lasted 4 min for diesel and 3 min for gasoline and naphtha, equivalent to a sample throughput of 7 h{sup -1} for diesel and 10 h{sup -1} for gasoline and naphtha. (orig.)

  6. Simultaneous determination of cadmium, iron and tin in canned foods using high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Leao, Danilo J; Junior, Mario M S; Brandao, Geovani C; Ferreira, Sergio L C

    2016-06-01

    A method was established to simultaneously determine cadmium, iron and tin in canned-food samples using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). The quantification step has been performed using the primary line (228.802nm) for cadmium and the adjacent secondary lines (228.725nm and 228.668nm) for iron and tin, respectively. The selected chemical modifier was an acid solution that contained a mixture of 0.1% (w/v) Pd and 0.05% (w/v) Mg. The absorbance signals were measured based on the peak area using 3 pixels for cadmium and 5 pixels for iron and tin. Under these conditions, cadmium, iron and tin have been determined in canned-food samples using the external calibration technique based on aqueous standards, where the limits of quantification were 2.10ngg(-1) for cadmium, 1.95mgkg(-1) for iron and 3.00mgkg(-1) for tin, and the characteristic masses were 1.0pg for cadmium, 0.9ng for iron and 1.1ng for tin. The precision was evaluated using two solutions of each metal ion, and the results, which were expressed as the relative standard deviation (RSD%), were 3.4-6.8%. The method accuracy for cadmium and iron was confirmed by analyzing a certified reference material of apple leaves (NIST 1515), which was supplied by NIST. However, for tin, the accuracy was confirmed by comparing the results of the proposed method and another analytical technique (inductively coupled plasma optical emission spectrometry). The proposed procedure was applied to determine cadmium, iron and tin in canned samples of peeled tomato and sardine. Eleven samples were analyzed, and the analyte concentrations were 3.57-62.9ngg(-1), 2.68-31.48mgkg(-1) and 4.06-122.0mgkg(-1) for cadmium, iron and tin, respectively. In all analyzed samples, the cadmium and tin contents were lower than the permissible maximum levels for these metals in canned foods in the Brazilian legislation. PMID:27130088

  7. Speciation and determination of ultra trace amounts of inorganic tellurium in environmental water samples by dispersive liquid-liquid microextraction and electrothermal atomic absorption spectrometry

    A simple and powerful method has been developed for the rapid and selective determination of Te(IV) and Te(VI), employing dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry using palladium as permanent modifier. Under acidic conditions pH 1, only Te(IV) can form a complex with ammonium pyrrolidine dithiocarbamate (APDC) and therefore be extracted into fine droplets of carbon tetrachloride (extraction solvent) which are dispersed with ethanol into the water sample solution. After centrifugation, Te(IV) was determined in the sedimented organic phase while Te(VI) remained in the aqueous phase. Total inorganic tellurium was determined after the reduction of the Te(VI) to Te(IV). Te(VI) was calculated as the difference between the measured total inorganic tellurium and Te(IV) content. The effective parameters for improving the efficiency of microextraction process were investigated by using experimental and central composite designs. Under optimal conditions the enrichment factor was 125 and the calibration graph was linear in the range of 0.015-1 ng mL-1 with detection limit and characteristic mass of 0.004 ng mL-1 and 0.033 pg, respectively. The relative standard deviation for 0.5 ng mL-1 of tellurium measurement was 3.6% (n = 6) at ash and atomization temperature, 900 and 2600 deg. C, respectively. The recoveries of spiked Te(IV) and Te(VI) to the environmental water samples were 89.6-101.3% and 96.6-99.1%, respectively. The accuracy is also evaluated by applying the proposed method to certified reference material (NIST SRM 1643e), for which the result was in a good agreement with the certified values reported for this CRM (95% confidence level).

  8. Method development for the determination of iron in milligram amounts of rice plants (Oryza sativa L.) from cultivation experiments using graphite furnace atomic absorption spectrometry

    Silva, Marcia M.; Vale, Maria Goreti R.; Damin, Isabel C. Ferreira [Instituto de Quimica, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Goncalves 9500, 91501-970, Porto Alegre RS (Brazil); Welz, Bernhard [Departamento de Quimica, Universidade Federal de Santa Catarina (UFSC), 88040-900, Florianopolis SC (Brazil); Mandaji, Marcos; Fett, Janette P. [Departamento de Botanica e Centro de Biotecnologia, Instituto de Biociencias, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Goncalves 9500, 91501-970, Porto Alegre RS (Brazil)

    2003-09-01

    The amount of sample that is available for analysis in laboratory plant cultivation experiments is usually very limited. Highly sensitive analytical techniques are therefore required, even for elements that are present in the plants at mg g{sup -1} concentrations, and graphite furnace atomic absorption spectrometry (GFAAS) was chosen in this work because of its micro-sampling capability, and its relatively simple operation. Four micro-methods were investigated for the determination of iron in roots and leaves of rice plants: (i) a micro-digestion with nitric and hydrochloric acids, (ii) a slurry procedure using tetramethylammonium hydroxide (TMAH) tissue solubilizer, (iii) a slurry prepared in 1.4 mol L{sup -1} nitric acid, and treated in an ultrasonic bath, and (iv) the direct analysis of solid samples. The micro-digestion was suffering from high blank values and contamination problems, so that it could not be recommended for routine purposes. The TMAH method exhibited poor precision and occasional low recoveries, particularly for real samples. Direct solid sampling analysis gave results similar to those obtained with the slurry technique with ultrasonic agitation for the determination of iron in certified reference materials with iron content up to about 100 {mu}g g{sup -1}, but was too sensitive for the investigated rice plants, which had an iron content up to several mg g{sup -1}. The slurry technique with ultrasonic treatment of the samples, suspended in dilute nitric acid, was finally adopted as the method of choice. The method was then applied for the determination of iron in the leaves and in different compartments of the roots of two rice cultivars, one sensitive to iron toxicity, an important nutritional disorder, and the other one resistant to iron toxicity. The results suggest that the higher resistance to iron toxicity of the second cultivar is due to a smaller uptake of iron from the soil, resulting in lower iron levels in all compartments of the

  9. Development of an analytical method for the determination of arsenic in gasoline samples by hydride generation–graphite furnace atomic absorption spectrometry

    The purpose of the present work was to optimize the conditions for the determination of arsenic in gasoline with hydride generation–graphite furnace atomic absorption spectrometry after acid digestion using a full two-level factorial design with center point. The arsine was generated in a batch system and collected in a graphite tube coated with 150 μg Ir as a permanent modifier. The sample volume, the pre-reduction conditions, the temperature program and modifier mass were kept fixed for all experiments. The estimated main effects were: reducing agent concentration (negative effect), acid concentration (negative effect) and trapping temperature (positive effect). It was observed that there were interactions between the variables. Moreover, the curvature was significant, indicating that the best conditions were at the center point. The optimized parameters for arsine generation were 2.7 mol L−1 hydrochloric acid and 1.6% (w/v) sodium tetrahydroborate. The optimized conditions to collect arsine in the graphite furnace were a trapping temperature of 250 °C and a collection time of 30 s. The limit of detection was 6.4 ng L−1 and the characteristic mass was 24 pg. Two different systems for acid digestion were used: a digester block with cold finger and a microwave oven. The concentration of arsenic found with the proposed method was compared with that obtained using a detergentless microemulsion and direct graphite furnace determination. The results showed that the factorial design is a simple tool that allowed establishing the appropriate conditions for sample preparation and also helped in evaluating the interaction between the factors investigated. - Highlights: ► We determined As in gasoline using hydride generation–graphite furnace AAS. ► We compared three sample preparation procedures. ► A multivariate approach was used to optimize the conditions. ► Analytical performance was best for semi-open digestion.

  10. Determination of lead and nickel in environmental samples by flame atomic absorption spectrometry after column solid-phase extraction on Ambersorb-572 with EDTA

    Lead and nickel were preconcentrated as their ethylenediaminetetraacedic acid (EDTA) complexes from aqueous sample solutions using a column containing Ambersorb-572 and determined by flame atomic absorption spectrometry (FAAS). pH values, amount of solid phase, elution solution and flow rate of sample solution have been optimized in order to obtain quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of Pb and Ni under the optimum conditions were 99 ± 2 and 97 ± 3%, respectively, at 95% confidence level. Seventy-five-fold (using 750 mL of sample solution and 10 mL of eluent) and 50-fold (using 500 mL of sample solution and 10 mL of eluent) preconcentration was obtained for Pb and Ni, respectively. Time of analysis is about 4.5 h (for obtaining enrichment factor of 75). By applying these enrichment factors, the analytical detection limits of Pb and Ni were found as 3.65 and 1.42 ng mL-1, respectively. The capacity of the sorbent was found as 0.17 and 0.21 mmol g-1 for Pb and Ni, respectively. The interferences of some cations, such as Mn2+, Co2+, Fe3+, Al3+, Zn2+, Cd2+, Ca2+, Mg2+, K+ and Na+ usually present in water samples were also studied. This procedure was applied to the determination of lead and nickel in parsley, green onion, sea water and waste water samples. The accuracy of the procedure was checked by determining Pb and Ni in standard reference tea leaves sample (GBW-07605). The results demonstrated good agreement with the certified values

  11. Evaluation of polychlorotrifluoroethylene as sorbent material for on-line solid phase extraction systems: Determination of copper and lead by flame atomic absorption spectrometry in water samples

    Polychlorotrifluoroethylene (PCTFE) in the form of beads was applied, as packing material for flow injection on-line column preconcentration and separation systems coupled with flame atomic absorption spectrometry (FAAS). Its performance characteristics were evaluated for trace copper determination in environmental samples. The on-line formed complex of metal with diethyldithiophosphate (DDPA) was sorbed on the PCTFE surface. Isobutyl methyl ketone (IBMK) at a flow rate of 2.8 mL min-1 was used to elute the analyte complex directly into the nebulizer-burner system of spectrophotometer. The proposed sorbent material reveal, excellent chemical and mechanical resistance, fast adsorption kinetics permitting the use of high sample flow rates up to 15 mL min-1 without loss of retention efficiency. For copper determination, with 90 s preconcentration time the sample frequency was 30 h-1, the enhancement factor was 250, which could be further improved by increasing the loading (preconcentration) time. The detection limit (3s) was c L = 0.07 μg L-1, and the precision (R.S.D.) was 1.8%, at the 2.0 μg L-1 Cu(II) level. For lead determination, the detection limit was c L = 2.7 μg L-1, and the precision (R.S.D.) 2.2%, at the 40.0 μg L-1 Pb(II) level. The accuracy of the developed method was evaluated by analyzing certified reference materials and by recovery measurements on spiked natural water samples

  12. Development of an analytical method for the determination of arsenic in gasoline samples by hydride generation-graphite furnace atomic absorption spectrometry

    Becker, Emilene M. [Universidade Federal do Pampa, Bage, RS (Brazil); Universidade Federal de Pelotas, Pelotas, RS (Brazil); Dessuy, Morgana B.; Boschetti, Wiliam [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R., E-mail: mgrvale@ufrgs.br [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Ferreira, Sergio L.C. [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Instituto de Quimica, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis, SC (Brazil)

    2012-05-15

    The purpose of the present work was to optimize the conditions for the determination of arsenic in gasoline with hydride generation-graphite furnace atomic absorption spectrometry after acid digestion using a full two-level factorial design with center point. The arsine was generated in a batch system and collected in a graphite tube coated with 150 {mu}g Ir as a permanent modifier. The sample volume, the pre-reduction conditions, the temperature program and modifier mass were kept fixed for all experiments. The estimated main effects were: reducing agent concentration (negative effect), acid concentration (negative effect) and trapping temperature (positive effect). It was observed that there were interactions between the variables. Moreover, the curvature was significant, indicating that the best conditions were at the center point. The optimized parameters for arsine generation were 2.7 mol L{sup -1} hydrochloric acid and 1.6% (w/v) sodium tetrahydroborate. The optimized conditions to collect arsine in the graphite furnace were a trapping temperature of 250 Degree-Sign C and a collection time of 30 s. The limit of detection was 6.4 ng L{sup -1} and the characteristic mass was 24 pg. Two different systems for acid digestion were used: a digester block with cold finger and a microwave oven. The concentration of arsenic found with the proposed method was compared with that obtained using a detergentless microemulsion and direct graphite furnace determination. The results showed that the factorial design is a simple tool that allowed establishing the appropriate conditions for sample preparation and also helped in evaluating the interaction between the factors investigated. - Highlights: Black-Right-Pointing-Pointer We determined As in gasoline using hydride generation-graphite furnace AAS. Black-Right-Pointing-Pointer We compared three sample preparation procedures. Black-Right-Pointing-Pointer A multivariate approach was used to optimize the conditions. Black

  13. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF6), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF6. After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 μL of HMIMPF6 as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L- 1, and the characteristic mass (m0, 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L- 1 Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  14. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    Li Shengqing [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Supervision, Inspection and Testing Center of Microbial Products Quality (Wuhan), Ministry of Agriculture (China)], E-mail: sqingli@mail.hzau.edu.cn; Cai Shun; Hu Wei [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Chen Hao [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China)], E-mail: hchenhao@mail.hzau.edu.cn; Liu Hanlan [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China)

    2009-07-15

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF{sub 6}), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF{sub 6}. After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 {mu}L of HMIMPF{sub 6} as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L{sup - 1}, and the characteristic mass (m{sub 0}, 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L{sup - 1} Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  15. Graphene-based solid-phase extraction combined with flame atomic absorption spectrometry for a sensitive determination of trace amounts of lead in environmental water and vegetable samples

    Wang Yukun; Gao Shutao; Zang Xiaohuan [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China); Li Jingci, E-mail: jingcili63@yahoo.com.cn [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China); Ma Jingjun, E-mail: majingjun@hebau.edu.cn [Hebei Key Laboratory of Bioinorganic Chemistry, College of Sciences, Agricultural University of Hebei, Baoding 071001 (China)

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer Graphene as a novel sorbent material in a column for solid-phase extraction (SPE). Black-Right-Pointing-Pointer SPE for the determination of lead (Pb) in environment water samples and vegetable samples. Black-Right-Pointing-Pointer The system can be reused for many times. Black-Right-Pointing-Pointer The adsorption capacity of graphene over many other adsorbents. Black-Right-Pointing-Pointer Graphene has great potentials as an excellent sorbent material. - Abstract: Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with graphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) using dithizone as chelating reagent prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 10.0-600.0 {mu}g L{sup -1} with a detection limit of 0.61 {mu}g L{sup -1}. The relative standard deviation for ten replicate measurements of 20.0 and 400.0 {mu}g L{sup -1} of Pb were 3.56 and 3.25%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Pb. The proposed method was successfully applied in the analysis of environmental water and vegetable samples. Good spiked recoveries over the range of 95.3-100.4% were obtained. This work not only proposes a useful method for sample preconcentration, but also reveals the great potential of graphene as an excellent sorbent material in analytical processes.

  16. Comparison of direct sampling and emulsion analysis using a filter furnace for the determination of lead in crude oil by graphite furnace atomic absorption spectrometry

    The determination of trace elements in crude oil is difficult due to the complex nature of the sample and the various different chemical forms in which the metals can occur. The advantage of graphite furnace atomic absorption spectrometry is that only a minimum of sample pretreatment is required. In this work two techniques have been compared to establish a fast and reliable method for lead determination in crude oil. In the first one the crude oil samples were weighed directly onto solid sampling (SS) platforms and introduced into the graphite tube for analysis. In the second one the samples were prepared as oil-in-water emulsions and analyzed in a filter furnace (FF). Twenty μL of a mixture of 0.5 mg L- 1 Pd + 0.3 mg L- 1 Mg + Triton X-100 has been used as the modifier, and calibration against aqueous solutions has been used for both methods. The sensitivity obtained with the FF was more than a factor of two better than that with SS; however, as a larger sample mass could be introduced in the latter case, so that the limits of detection for both techniques were 0.004 mg kg- 1. Seven crude oil samples were analyzed using the two procedures, and all results were in agreement at a 95% confidence level using a paired Student's t-test. For validation purposes, three crude oil samples have been mineralized using an open-vessel acid digestion, and the results were in agreement with those found with direct sampling and with emulsion sampling using FF according to ANOVA test. Both methods are simple, fast and reliable, being appropriated for routine analysis; however, the direct method using SS technology should be preferred because of its simplicity, speed and commercial availability.

  17. Multiple response optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry with sample injection as detergent emulsion

    Brum, Daniel M.; Lima, Claudio F. [Departamento de Quimica, Universidade Federal de Vicosa, A. Peter Henry Rolfs s/n, Vicosa/MG, 36570-000 (Brazil); Robaina, Nicolle F. [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de S.J. Batista s/n, Centro, Niteroi/RJ, 24020-141 (Brazil); Fonseca, Teresa Cristina O. [Petrobras, Cenpes/PDEDS/QM, Av. Horacio Macedo 950, Ilha do Fundao, Rio de Janeiro/RJ, 21941-915 (Brazil); Cassella, Ricardo J., E-mail: cassella@vm.uff.br [Departamento de Quimica Analitica, Universidade Federal Fluminense, Outeiro de S.J. Batista s/n, Centro, Niteroi/RJ, 24020-141 (Brazil)

    2011-05-15

    The present paper reports the optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry (GF AAS) employing a strategy based on the injection of the samples as detergent emulsions. The method was optimized in relation to the experimental conditions for the emulsion formation and taking into account that the three analytes (Cu, Fe and Pb) should be measured in the same emulsion. The optimization was performed in a multivariate way by employing a three-variable Doehlert design and a multiple response strategy. For this purpose, the individual responses of the three analytes were combined, yielding a global response that was employed as a dependent variable. The three factors related to the optimization process were: the concentration of HNO{sub 3}, the concentration of the emulsifier agent (Triton X-100 or Triton X-114) in aqueous solution used to emulsify the sample and the volume of solution. At optimum conditions, it was possible to obtain satisfactory results with an emulsion formed by mixing 4 mL of the samples with 1 mL of a 4.7% w/v Triton X-100 solution prepared in 10% v/v HNO{sub 3} medium. The resulting emulsion was stable for 250 min, at least, and provided enough sensitivity to determine the three analytes in the five samples tested. A recovery test was performed to evaluate the accuracy of the optimized procedure and recovery rates, in the range of 88-105%; 94-118% and 95-120%, were verified for Cu, Fe and Pb, respectively.

  18. Polymer-supported ionic liquid solid phase extraction for trace inorganic and organic mercury determination in water samples by flow injection-cold vapor atomic absorption spectrometry.

    Escudero, Leticia B; Olsina, Roberto A; Wuilloud, Rodolfo G

    2013-11-15

    A simple and green technique named polymer-supported ionic liquid solid phase extraction (PSIL-SPE) was developed for mercury (Hg) species determination. Inorganic Hg (InHg) species was complexed with chloride ions followed by its introduction into a flow injection on-line system to quantitatively retain the anionic chlorocomplex (HgCl4(2-)) in a column packed with CYPHOS(®) IL 101-impregnated resin. The trapped InHg was then reduced with stannous chloride (SnCl2) and eluted with the same flow of reducing agent followed by cold vapor atomic absorption spectrometry (CV-AAS) detection. Organic mercury species (OrgHg) did not interact with the impregnated resin and were not retained into the column. Total concentration of OrgHg was evaluated by difference between total Hg and InHg concentration. A 95% extraction efficiency was achieved for InHg when the procedure was developed under optimal experimental conditions. The limit of detection obtained for preconcentration of 40 mL of sample was 2.4 ng L(-1) InHg. The relative standard deviation (RSD) was 2.7% (at 1 µg L(-1) InHg and n=10) calculated from the peak height of absorbance signals (Gaussian-shape and reproducible peaks). This work reports the first polymer-supported IL solid phase extraction approach implemented in a flow injection on-line system for determination of Hg species in mineral, tap and river water samples. PMID:24148384

  19. Use of cetyltrimethylammonium bromide as surfactant for the determination of copper and chromium in gasoline emulsions by electrothermal atomic absorption spectrometry

    In this work, the use of cetyltrimethylammonium bromide as surfactant for the preparation of oil-in-water emulsions for the determination of Cu and Cr in gasoline by electrothermal atomic absorption spectrometry (ET AAS) was evaluated. The surfactant amount was tested in the range of 25 to 300 mg, added to 2 ml of gasoline, and completed to 10 mL with 0.1% (v/v) nitric acid solution. 150 mg of surfactant was found optimum, and a sonication time of 10 min sufficient to form an oil-in-water emulsion that was stable for several hours. The ET AAS temperature program was established based on pyrolysis and atomization curves. The pyrolysis temperatures were set at 700 and 1300 deg. C for Cu and Cr, respectively and the selected atomization temperatures were 2400 and 2500 deg. C. The time and temperature of the drying stage and the atomization time were experimentally tested to provide optimum conditions. The limits of detection were found to be 5 μg L-1 and 1.5 μg L-1 for Cu and Cr, respectively in the original gasoline samples. The relative standard deviation (RSD) ranged from 4 to 9% in oil-in-water emulsions spiked with 5 μg L-1 and 15 μg L-1 of each metal, respectively. Recoveries varied from 90 to 98%. The accuracy of the proposed method was tested by an alternate procedure using complete evaporation of the gasoline sample. The method was adequate for the determination of Cu and Cr in gasoline samples collected from different gas stations in Salvador, BA, Brazil

  20. Preparation of modified magnetic nanoparticles as a sorbent for the preconcentration and determination of cadmium ions in food and environmental water samples prior to flame atomic absorption spectrometry

    Mirabi, Ali; Dalirandeh, Zeinab [Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Rad, Ali Shokuhi, E-mail: a.shokuhi@qaemshahriau.ac.ir [Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of)

    2015-05-01

    A new method has been developed for the separation/preconcentration of trace level cadmium ions using diphenyl carbazone/sodium dodecyl sulfate immobilized on magnetic nanoparticle Fe{sub 3}O{sub 4} as a new sorbent SPE and their determination by flame atomic absorption spectrometry (FAAS). Synthesized nanoparticle was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Various influencing parameters on the separation and preconcentration of trace level cadmium ions such as, pH value, amount of nanoparticles, amount of diphenyl carbazone, condition of eluting solution, the effects of matrix ions were examined. The cadmium ions can be eluted from the modified magnetic nanoparticle using 1 mol L{sup −1} HCl as a desorption reagent. The detection limit of this method for cadmium was 3.71 ng ml{sup −1} and the R.S.D. was 0.503% (n=6). The advantages of this new method include rapidity, easy preparation of sorbents and a high concentration factor. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, green tea, rice, tobacco, carrot, lettuce, ginseng, spice, tap water, river water, sea water with satisfactory results. - Highlights: • MNPs method is economical, simple, rapid and sensitive for trace analysis of Cd. • High preconcentration factor was obtained easily through this method. • A detection limit at ng mL{sup −1} level was achieved with 100.0 mL of sample. • This method provides good repeatability and extraction efficiency in a short time.

  1. Preparation of modified magnetic nanoparticles as a sorbent for the preconcentration and determination of cadmium ions in food and environmental water samples prior to flame atomic absorption spectrometry

    A new method has been developed for the separation/preconcentration of trace level cadmium ions using diphenyl carbazone/sodium dodecyl sulfate immobilized on magnetic nanoparticle Fe3O4 as a new sorbent SPE and their determination by flame atomic absorption spectrometry (FAAS). Synthesized nanoparticle was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Various influencing parameters on the separation and preconcentration of trace level cadmium ions such as, pH value, amount of nanoparticles, amount of diphenyl carbazone, condition of eluting solution, the effects of matrix ions were examined. The cadmium ions can be eluted from the modified magnetic nanoparticle using 1 mol L−1 HCl as a desorption reagent. The detection limit of this method for cadmium was 3.71 ng ml−1 and the R.S.D. was 0.503% (n=6). The advantages of this new method include rapidity, easy preparation of sorbents and a high concentration factor. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, green tea, rice, tobacco, carrot, lettuce, ginseng, spice, tap water, river water, sea water with satisfactory results. - Highlights: • MNPs method is economical, simple, rapid and sensitive for trace analysis of Cd. • High preconcentration factor was obtained easily through this method. • A detection limit at ng mL−1 level was achieved with 100.0 mL of sample. • This method provides good repeatability and extraction efficiency in a short time

  2. Multiple response optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry with sample injection as detergent emulsion

    The present paper reports the optimization for Cu, Fe and Pb determination in naphtha by graphite furnace atomic absorption spectrometry (GF AAS) employing a strategy based on the injection of the samples as detergent emulsions. The method was optimized in relation to the experimental conditions for the emulsion formation and taking into account that the three analytes (Cu, Fe and Pb) should be measured in the same emulsion. The optimization was performed in a multivariate way by employing a three-variable Doehlert design and a multiple response strategy. For this purpose, the individual responses of the three analytes were combined, yielding a global response that was employed as a dependent variable. The three factors related to the optimization process were: the concentration of HNO3, the concentration of the emulsifier agent (Triton X-100 or Triton X-114) in aqueous solution used to emulsify the sample and the volume of solution. At optimum conditions, it was possible to obtain satisfactory results with an emulsion formed by mixing 4 mL of the samples with 1 mL of a 4.7% w/v Triton X-100 solution prepared in 10% v/v HNO3 medium. The resulting emulsion was stable for 250 min, at least, and provided enough sensitivity to determine the three analytes in the five samples tested. A recovery test was performed to evaluate the accuracy of the optimized procedure and recovery rates, in the range of 88-105%; 94-118% and 95-120%, were verified for Cu, Fe and Pb, respectively.

  3. Determination of arsenic(III) and arsenic(V) by electrothermal atomic absorption spectrometry after complexation and sorption on a C-18 bonded silica column.

    Pozebon, D; Dressler, V L; Gomes Neto, J A; Curtius, A J

    1998-04-01

    A flow injection procedure for the separation and pre-concentration of inorganic arsenic based on the complexation with ammonium diethyl dithiophosphate (DDTP) and sorption on a C-18 bonded silica gel minicolumn is proposed. During the sample injection by a time-based fashion, the As(3+)-DDTP complex is stripped from the solution and retained in the column. Arsenic(V) and other ions that do not form complexes are discarded. After reduction to the trivalent state by using potassium iodide plus ascorbic acid, total arsenic is determined by electrothermal atomic absorption spectrometry (ETAAS). Arsenic(V) concentration can be calculated by difference. After processing 6 ml sample volume, the As(3+)-DDTP complexes were eluted directly into the autosampler cup (120 mul). Ethanol was used for column rinsing. Influence of pH, reagent concentration, pre-concentration and elution time and column size were investigated. When 30 mul of eluate plus 10 mul of 0.1% (w/v) Pd(NO(3))(2) were dispensed into the graphite tube, analytical curve in the 0.3-3 mug As l(-1) range was obtained (r=0.9991). The accuracy was checked for arsenic determination in a certified water, spiked tap water and synthetic mixtures of arsenite and arsenate. Good recoveries (97-108%) of spiked samples were found. Results are precise (RSD 7.5 and 6% for 0.5 and 2.5 mug l(-1), n=10) and in agreement with the certified value of reference material at 95% confidence level. PMID:18967109

  4. Comparison of direct sampling and emulsion analysis using a filter furnace for the determination of lead in crude oil by graphite furnace atomic absorption spectrometry

    Damin, Isabel C.F.; Dessuy, Morgana B.; Castilhos, Tamara S. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre - RS (Brazil); Silva, Marcia M. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre - RS (Brazil)], E-mail: mmsilva@iq.ufrgs.br; Vale, Maria Goreti R. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre - RS (Brazil); Welz, Bernhard [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis - SC (Brazil); Katskov, Dmitri A. [Tshwane University of Technology (TUT), Faculty of Science, Chemistry Department, Pretoria 0001 (South Africa)

    2009-06-15

    The determination of trace elements in crude oil is difficult due to the complex nature of the sample and the various different chemical forms in which the metals can occur. The advantage of graphite furnace atomic absorption spectrometry is that only a minimum of sample pretreatment is required. In this work two techniques have been compared to establish a fast and reliable method for lead determination in crude oil. In the first one the crude oil samples were weighed directly onto solid sampling (SS) platforms and introduced into the graphite tube for analysis. In the second one the samples were prepared as oil-in-water emulsions and analyzed in a filter furnace (FF). Twenty {mu}L of a mixture of 0.5 mg L{sup - 1} Pd + 0.3 mg L{sup - 1} Mg + Triton X-100 has been used as the modifier, and calibration against aqueous solutions has been used for both methods. The sensitivity obtained with the FF was more than a factor of two better than that with SS; however, as a larger sample mass could be introduced in the latter case, so that the limits of detection for both techniques were 0.004 mg kg{sup - 1}. Seven crude oil samples were analyzed using the two procedures, and all results were in agreement at a 95% confidence level using a paired Student's t-test. For validation purposes, three crude oil samples have been mineralized using an open-vessel acid digestion, and the results were in agreement with those found with direct sampling and with emulsion sampling using FF according to ANOVA test. Both methods are simple, fast and reliable, being appropriated for routine analysis; however, the direct method using SS technology should be preferred because of its simplicity, speed and commercial availability.

  5. Preconcentration and determination of vanadium and molybdenum in milk, vegetables and foodstuffs by ultrasonic-thermostatic-assisted cloud point extraction coupled to flame atomic absorption spectrometry.

    Gürkan, Ramazan; Korkmaz, Sema; Altunay, Nail

    2016-08-01

    A new ultrasonic-thermostatic-assisted cloud point extraction procedure (UTA-CPE) was developed for preconcentration at the trace levels of vanadium (V) and molybdenum (Mo) in milk, vegetables and foodstuffs prior to determination via flame atomic absorption spectrometry (FAAS). The method is based on the ion-association of stable anionic oxalate complexes of V(V) and Mo(VI) with [9-(diethylamino)benzo[a]phenoxazin-5-ylidene]azanium; sulfate (Nile blue A) at pH 4.5, and then extraction of the formed ion-association complexes into micellar phase of polyoxyethylene(7.5)nonylphenyl ether (PONPE 7.5). The UTA-CPE is greatly simplified and accelerated compared to traditional cloud point extraction (CPE). The analytical parameters optimized are solution pH, the concentrations of complexing reagents (oxalate and Nile blue A), the PONPE 7.5 concentration, electrolyte concentration, sample volume, temperature and ultrasonic power. Under the optimum conditions, the calibration curves for Mo(VI) and V(V) are obtained in the concentration range of 3-340µgL(-1) and 5-250µgL(-1) with high sensitivity enhancement factors (EFs) of 145 and 115, respectively. The limits of detection (LODs) for Mo(VI) and V(V) are 0.86 and 1.55µgL(-1), respectively. The proposed method demonstrated good performances such as relative standard deviations (as RSD %) (≤3.5%) and spiked recoveries (95.7-102.3%). The accuracy of the method was assessed by analysis of two standard reference materials (SRMs) and recoveries of spiked solutions. The method was successfully applied into the determination of trace amounts of Mo(VI) and V(V) in milk, vegetables and foodstuffs with satisfactory results. PMID:27216654

  6. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    Li, Shengqing; Cai, Shun; Hu, Wei; Chen, Hao; Liu, Hanlan

    2009-07-01

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF 6), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF 6. After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 µL of HMIMPF 6 as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L - 1 , and the characteristic mass ( m0, 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L - 1 Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  7. Dithiocarbamate functionalized or surface sorbed Merrifield resin beads as column materials for on line flow injection-flame atomic absorption spectrometry determination of lead

    This article describes the preparation of dithiocarbamate immobilized/functionalized and diethylammonium dithiocarbamate (DDTC) sorbed Merrifield Chloromethylated Resin (MCR) beads and comparison of these materials for on-line flow injection (FI)-flame atomic absorption spectrometry (FAAS) determination of lead. The above two materials enrich lead quantitatively over an identical optimal pH range (8.0-9.0), a preconcentration/loading time (up to 4 min) and elution with acidified methanol (a minimum of 0.01 mol L-1 HNO3 in methanol). However, the detection limit for lead using dithiocarbamate functionalized MCR beads is 1.3 μg L-1 compared to 3 μg L-1 for DDTC sorbed MCR beads. Again, the sensitivity enhancement over direct FAAS signal is 48- and 27-fold, respectively. In addition, dithiocarbamate functionalized MCR beads offers better precision compared to DDTC sorbed MCR beads as the corresponding relative standard deviation (R.S.D.) values for five successive determinations of 0.20 μg mL-1 are 1.44 and 4.36%, respectively. The accuracy of the developed on-line FI-FAAS procedure employing dithiocarbamate functionalized MCR beads as column material was tested by analyzing Certified Reference Material (CRM) of soil (IAEA soil-7) and marine sediment reference material (MESS-3) supplied by International Atomic Energy Agency (IAEA), Vienna and National Research Council (NRC), Canada, respectively. Furthermore, the developed procedure has been successfully tested for the analysis of surface, pond, ground and effluent water and soil samples collected from the vicinity of lead acid battery industry in India

  8. Noble metals as permanent chemical modifiers for the determination of mercury in environmental reference materials using solid sampling graphite furnace atomic absorption spectrometry and calibration against aqueous standards

    da Silva, Alessandra Furtado; Welz, Bernhard; Curtius, Adilson J.

    2002-12-01

    Iridium, palladium, rhodium and ruthenium, thermally deposited on the platform, were investigated as permanent modifiers for the determination of mercury in ash, sludge, marine and river sediment reference materials, ground to a particle size of 50 μm, using solid sampling graphite furnace atomic absorption spectrometry. A total mass of 250 μg of each modifier was applied using 25 injections of 20 μl of modifier solution (500 mg l -1), and executing a temperature program for modifier conditioning after each injection. The performance of palladium was found to be most consistent, taking the characteristic mass as the major criterion, resulting in an excellent correlation between the measured integrated absorbance values and the certified mercury contents. Mercury was found to be lost in part from aqueous solutions during the drying stage in the presence of all the investigated permanent modifiers, as well as in the presence of the palladium and magnesium nitrates modifier added in solution. A loss-free determination of mercury in aqueous solutions could be reached only after the addition of potassium permanganate, which finally made possible the use of aqueous standards for the direct analysis of solid samples. A characteristic mass of 55-60 pg Hg was obtained for the solid samples, using Pd as a permanent modifier, and also in aqueous solutions after the addition of permanganate. The results obtained for mercury in ash, sludge and sediment reference materials, using direct solid sapling and calibration against aqueous standards, as well as the detection limit of 0.2 mg kg -1 were satisfactory for a routine procedure.

  9. Noble metals as permanent chemical modifiers for the determination of mercury in environmental reference materials using solid sampling graphite furnace atomic absorption spectrometry and calibration against aqueous standards

    Silva, Alessandra Furtado da; Welz, Bernhard; Curtius, Adilson J

    2002-12-02

    Iridium, palladium, rhodium and ruthenium, thermally deposited on the platform, were investigated as permanent modifiers for the determination of mercury in ash, sludge, marine and river sediment reference materials, ground to a particle size of 50 {mu}m, using solid sampling graphite furnace atomic absorption spectrometry. A total mass of 250 {mu}g of each modifier was applied using 25 injections of 20 {mu}l of modifier solution (500 mg l{sup -1}), and executing a temperature program for modifier conditioning after each injection. The performance of palladium was found to be most consistent, taking the characteristic mass as the major criterion, resulting in an excellent correlation between the measured integrated absorbance values and the certified mercury contents. Mercury was found to be lost in part from aqueous solutions during the drying stage in the presence of all the investigated permanent modifiers, as well as in the presence of the palladium and magnesium nitrates modifier added in solution. A loss-free determination of mercury in aqueous solutions could be reached only after the addition of potassium permanganate, which finally made possible the use of aqueous standards for the direct analysis of solid samples. A characteristic mass of 55-60 pg Hg was obtained for the solid samples, using Pd as a permanent modifier, and also in aqueous solutions after the addition of permanganate. The results obtained for mercury in ash, sludge and sediment reference materials, using direct solid sapling and calibration against aqueous standards, as well as the detection limit of 0.2 mg kg{sup -1} were satisfactory for a routine procedure.

  10. Determination of cadmium and lead in urine samples after dispersive solid–liquid extraction on multiwalled carbon nanotubes by slurry sampling electrothermal atomic absorption spectrometry

    Álvarez Méndez, J.; Barciela García, J.; García Martín, S.; Peña Crecente, R.M.; Herrero Latorre, C., E-mail: carlos.herrero@usc.es

    2015-04-01

    A new method for the determination of Cd and Pb in urine samples has been developed. The method involves dispersive solid-phase extraction (DSPE), slurry sampling (SS), and subsequent electrothermal atomic absorption spectrometry (ETAAS). Oxidized multiwalled carbon nanotubes (MWCNTs) were used as the sorbent material. The isolated MWCNT/analyte aggregates were treated with nitric acid to form a slurry and both metals were determined directly by injecting the slurry into the ETAAS-atomizer. The parameters that influence the adsorption of the metals on MWCNTs in the DSPE process, the formation and extraction of the slurry, and the ETAAS conditions were studied by different factorial design strategies. The detection and quantification limits obtained for Cd under optimized conditions were 9.7 and 32.3 ng L{sup −1}, respectively, and for Pb these limits were 0.13 and 0.43 μg L{sup −1}. The preconcentration factors achieved were 3.9 and 5.4. The RSD values (n = 10) were less than 4.1% and 5.9% for Cd and Pb, respectively. The accuracy of the method was assessed in recovery studies, with values in the range 96–102% obtained for Cd and 97–101% for Pb. In addition, the analysis of certified reference materials gave consistent results. The DSPE–SS–ETAAS method is a novel and useful strategy for the determination of Pb and Cd at low levels in human urine samples. The method is sensitive, fast, and free of matrix interferences, and it avoids the tedious and time-consuming on-column adsorption and elution steps associated with commonly used SPE procedures. The proposed method was used to determine Cd and Pb in urine samples of unexposed healthy people and satisfactory results were obtained. - Highlights: • Cd and Pb determination based on the combination of DSP, SS and ETAAS • Urine matrix was eliminated using DSPE based on multiwalled carbon nanotubes. • Slurry sampling technique permitted the direct injection of sample into the ETAAS atomizer.

  11. Determination of cadmium and lead in urine samples after dispersive solid–liquid extraction on multiwalled carbon nanotubes by slurry sampling electrothermal atomic absorption spectrometry

    A new method for the determination of Cd and Pb in urine samples has been developed. The method involves dispersive solid-phase extraction (DSPE), slurry sampling (SS), and subsequent electrothermal atomic absorption spectrometry (ETAAS). Oxidized multiwalled carbon nanotubes (MWCNTs) were used as the sorbent material. The isolated MWCNT/analyte aggregates were treated with nitric acid to form a slurry and both metals were determined directly by injecting the slurry into the ETAAS-atomizer. The parameters that influence the adsorption of the metals on MWCNTs in the DSPE process, the formation and extraction of the slurry, and the ETAAS conditions were studied by different factorial design strategies. The detection and quantification limits obtained for Cd under optimized conditions were 9.7 and 32.3 ng L−1, respectively, and for Pb these limits were 0.13 and 0.43 μg L−1. The preconcentration factors achieved were 3.9 and 5.4. The RSD values (n = 10) were less than 4.1% and 5.9% for Cd and Pb, respectively. The accuracy of the method was assessed in recovery studies, with values in the range 96–102% obtained for Cd and 97–101% for Pb. In addition, the analysis of certified reference materials gave consistent results. The DSPE–SS–ETAAS method is a novel and useful strategy for the determination of Pb and Cd at low levels in human urine samples. The method is sensitive, fast, and free of matrix interferences, and it avoids the tedious and time-consuming on-column adsorption and elution steps associated with commonly used SPE procedures. The proposed method was used to determine Cd and Pb in urine samples of unexposed healthy people and satisfactory results were obtained. - Highlights: • Cd and Pb determination based on the combination of DSP, SS and ETAAS • Urine matrix was eliminated using DSPE based on multiwalled carbon nanotubes. • Slurry sampling technique permitted the direct injection of sample into the ETAAS atomizer. • Appropriate

  12. Suspended nanoparticles in surfactant media as a microextraction technique for simultaneous separation and preconcentration of cobalt, nickel and copper ions for electrothermal atomic absorption spectrometry determination.

    Dadfarnia, Shayessteh; Shakerian, Farid; Shabani, Ali Mohammad Haji

    2013-03-15

    The aim of this study was to describe a new method of microextraction based on the suspension of alumina nanoparticles in the surfactant media for simultaneous separation and preconcentration of the ultra-traces of cobalt, nickel and copper ions. In this technique, the alumina nanoparticles were suspended in the non-ionic surfactant solution of Triton X-114. The analytes in the sample solution were adsorbed onto the nanoparticles. After the phase separation based on the cloud point of the mixture at 40 °C, the nanoparticles settled down in the surfactant rich phase. Then 120 μL of nitric acid (3.0 mol L(-1)) was added to the surfactant rich phase which caused desorption of the analytes. Finally, the liquid phase was separated by centrifugation from the nanoparticles and was used for the quantification of the analytes by the electrothermal atomic absorption spectrometry (ETAAS). The parameters affecting the extraction and detection processes were optimized. Under the optimized experimental conditions (i.e. pH∼8, Triton X-114, 0.05% (v/v); temperature 40 °C), a sample volume of 25 mL resulted in the enhancement factors of 198, 205 and 206 and detection limits (defined as 3Sb/m) of 2.5, 2.8 and 2.6 ng L(-1) for Co(II), Ni(II) and Cu(II) respectively. The sorbent showed high capacity for these metal ions (30-40 mg g(-1) sorbent). The method was successfully applied to the determination of the analytes in natural water samples. PMID:23598108

  13. Activated carbon-modified knotted reactor coupled to electrothermal atomic absorption spectrometry for sensitive determination of arsenic species in medicinal herbs and tea infusions

    A flow injection system based on a modified polytetrafluoroethylene (PTFE) knotted reactor (KR) was developed for arsenite [As(III)] and arsenate [As(V)] species preconcentration and determination by electrothermal atomic absorption spectrometry (ETAAS). Activated carbon (AC) was immobilized on the inner walls of a PTFE KR by a thermal treatment. A significant increase in analyte retention was obtained with the AC-modified KR (100%) as compared to the regular PTFE KR (25%). The preconcentration method involved the on-line formation of As(III)-ammonium pyrrolidinedithiocarbamate (As-APDC) complex, followed by its adsorption onto the inner walls of the AC-modified KR. After analyte retention, the complex was eluted with acetone directly into the graphite furnace of ETAAS. The parameters affecting the flow injection system were evaluated with a full central composite face centered design with three center points. Under optimum conditions, a preconcentration factor of 200 was obtained with 10 ml of sample. The detection limit was 4 ng L−1 and the relative standard deviation (RSD) for six replicate measurements at 0.2 μg L−1 of As were 4.3% and 4.7% for As(III) and As(V), respectively. The developed methodology was highly selective towards As(III), while As(V), monomethylarsonic acid [MMA(V)] and dimethylarsinic [DMA(V)] were not retained in the AC-modified KR. The proposed method was successfully applied for As speciation analysis in infusions originated from medicinal herbs and tea. - Highlights: • We report an efficient method for As speciation. • We have modified a knotted reactor with activated carbon for high sorption capacity. • We provide a simple procedure for surface modification of a PTFE knotted reactor. • We have selectively separated inorganic As species from complex matrix samples. • We have implemented a modified KR in a flow injection system coupled to ETAAS

  14. Green method for ultrasensitive determination of Hg in natural waters by electrothermal-atomic absorption spectrometry following sono-induced cold vapor generation and 'in-atomizer trapping'

    Sono-induced cold vapor generation (SI-CVG) has been used for the first time in combination with a graphite furnace atomizer for determination of Hg in natural waters by electrothermal-atomic absorption spectrometry after in situ trapping onto a noble metal-pretreated platform (Pd, Pt or Rh) inserted into a graphite tube. The system allows 'in-atomizer trapping' of Hg without the use of conventional reduction reactions based on sodium borohydride or tin chloride in acid medium for cold vapor generation. The sono-induced reaction is accomplished by applying ultrasound irradiation to the sample solution containing Hg(II) in the presence of an organic compound such as formic acid. As this organic acid is partly degraded upon ultrasound irradiation to yield CO, CO2, H2 and H2O, the amount of lab wastes is minimized and a green methodology is achieved. For this purpose, experimental variables influencing the generation/trapping process are fully investigated. The limit of detection for a 10 min trapping time and 10 mL sample volume was 0.03 μg L-1 (Integrated absorbance) and the repeatability expressed as relative standard deviation was about 3%. Carbonates and chlorides at 100 mg L-1 level caused a signal depression by 20-30%. The enhanced trapping efficiency observed with the sono-induced cold vapor generation as compared with 'in-atomizer trapping' methods employing chemical vapor generation is discussed. A reaction pathway for SI-CVG is proposed on the basis of the current knowledge for synthesis of noble metal nanoparticles by ultrasound

  15. Studies of ion-imprinted polymers for solid-phase extraction of ruthenium from environmental samples before its determination by electrothermal atomic absorption spectrometry

    Zambrzycka, Elzbieta; Roszko, Dorota; Lesniewska, Barbara; Wilczewska, Agnieszka Z.; Godlewska-Zylkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

    2011-07-15

    The examination of the effect of interfering ions on the analytical signal of ruthenium measured by electrothermal atomic absorption spectrometry was initially performed in this work. The complexes of ruthenium(III) with thiosemicarbazide (TSd) and acetaldehyde thiosemicarbazone (AcTSn) were prepared and imprinted in polymeric network. The ion-imprinted polymers were synthesized by copolymerization of methacrylic acid, as functional monomer and ethylene glycol dimethacrylate, as crosslinking agent in the presence of 2,2-azobisisobutyronitrile as initiator. The effects of sample volume, pH, and flow rate on the extraction of analyte were studied in dynamic mode. The optimum pH for quantitative retention of ruthenium on each of the studied sorbents was 7.5 {+-} 0.5. The elution of analyte was completed with 0.2 mol L{sup -1} thiourea in 0.2 mol L{sup -1} HCl. The effect of matrix ions on ruthenium(III) separation process was studied. The analytical performance of the Ru-TSd polymer in the presence of competing ions was better than Ru-AcTSn polymer, considering recovery of analyte, reproducibility of results, selectivity coefficients, and sorbent capacity. The detection limit of the proposed method (0.16 ng mL{sup -1} on Ru-TSd and 0.25 ng mL{sup -1} on Ru-AcTSn) is lower in comparison with the previously published methods. The developed separation method was successfully applied to the determination of trace amounts of ruthenium in spiked water samples, sludge, grass, and human hair.

  16. Studies of ion-imprinted polymers for solid-phase extraction of ruthenium from environmental samples before its determination by electrothermal atomic absorption spectrometry

    Zambrzycka, Elżbieta; Roszko, Dorota; Leśniewska, Barbara; Wilczewska, Agnieszka Z.; Godlewska-Żyłkiewicz, Beata

    2011-07-01

    The examination of the effect of interfering ions on the analytical signal of ruthenium measured by electrothermal atomic absorption spectrometry was initially performed in this work. The complexes of ruthenium(III) with thiosemicarbazide (TSd) and acetaldehyde thiosemicarbazone (AcTSn) were prepared and imprinted in polymeric network. The ion-imprinted polymers were synthesized by copolymerization of methacrylic acid, as functional monomer and ethylene glycol dimethacrylate, as crosslinking agent in the presence of 2,2-azobisisobutyronitrile as initiator. The effects of sample volume, pH, and flow rate on the extraction of analyte were studied in dynamic mode. The optimum pH for quantitative retention of ruthenium on each of the studied sorbents was 7.5 ± 0.5. The elution of analyte was completed with 0.2 mol L -1 thiourea in 0.2 mol L -1 HCl. The effect of matrix ions on ruthenium(III) separation process was studied. The analytical performance of the Ru-TSd polymer in the presence of competing ions was better than Ru-AcTSn polymer, considering recovery of analyte, reproducibility of results, selectivity coefficients, and sorbent capacity. The detection limit of the proposed method (0.16 ng mL -1 on Ru-TSd and 0.25 ng mL -1 on Ru-AcTSn) is lower in comparison with the previously published methods. The developed separation method was successfully applied to the determination of trace amounts of ruthenium in spiked water samples, sludge, grass, and human hair.

  17. Studies of ion-imprinted polymers for solid-phase extraction of ruthenium from environmental samples before its determination by electrothermal atomic absorption spectrometry

    The examination of the effect of interfering ions on the analytical signal of ruthenium measured by electrothermal atomic absorption spectrometry was initially performed in this work. The complexes of ruthenium(III) with thiosemicarbazide (TSd) and acetaldehyde thiosemicarbazone (AcTSn) were prepared and imprinted in polymeric network. The ion-imprinted polymers were synthesized by copolymerization of methacrylic acid, as functional monomer and ethylene glycol dimethacrylate, as crosslinking agent in the presence of 2,2-azobisisobutyronitrile as initiator. The effects of sample volume, pH, and flow rate on the extraction of analyte were studied in dynamic mode. The optimum pH for quantitative retention of ruthenium on each of the studied sorbents was 7.5 ± 0.5. The elution of analyte was completed with 0.2 mol L-1 thiourea in 0.2 mol L-1 HCl. The effect of matrix ions on ruthenium(III) separation process was studied. The analytical performance of the Ru-TSd polymer in the presence of competing ions was better than Ru-AcTSn polymer, considering recovery of analyte, reproducibility of results, selectivity coefficients, and sorbent capacity. The detection limit of the proposed method (0.16 ng mL-1 on Ru-TSd and 0.25 ng mL-1 on Ru-AcTSn) is lower in comparison with the previously published methods. The developed separation method was successfully applied to the determination of trace amounts of ruthenium in spiked water samples, sludge, grass, and human hair.

  18. Determination of Pb (Lead, Cd (Cadmium, Cr (Chromium, Cu (Copper, and Ni (Nickel in Chinese tea with high-resolution continuum source graphite furnace atomic absorption spectrometry

    Wen-Si Zhong

    2016-01-01

    Full Text Available The contents of lead, cadmium, chromium, copper, and nickel were determined in 25 tea samples from China, including green, yellow, white, oolong, black, Pu'er, and jasmine tea products, using high-resolution continuum source graphite furnace atomic absorption spectrometry. The methods used for sample preparation, digestion, and quantificational analysis were established, generating satisfactory analytical precisions (represented by relative standard deviations ranging from 0.6% to 2.5% and recoveries (98.91–101.32%. The lead contents in tea leaves were 0.48–10.57 mg/kg, and 80% of these values were below the maximum values stated by the guidelines in China. The contents of cadmium and chromium ranged from 0.01 mg/kg to 0.39 mg/kg and from 0.27 mg/kg to 2.45 mg/kg, respectively, remaining in compliance with the limits stipulated by China's Ministry of Agriculture. The copper contents were 7.73–63.71 mg/kg; only 64% of these values complied with the standards stipulated by the Ministry of Agriculture. The nickel contents ranged from 2.70 mg/kg to 13.41 mg/kg. Consequently, more attention must be paid to the risks of heavy metal contamination in tea. The quantitative method established in this work lays a foundation for preventing heavy metal toxicity in human from drinking tea and will help establish regulations to control the contents of heavy metals in tea.

  19. Determination of Chromium(III), Chromium(VI), and Chromium(III) acetylacetonate in water by ion-exchange disk extraction/metal furnace atomic absorption spectrometry

    Kamakura, Nao, E-mail: minnie04_tb@yahoo.co.jp; Inui, Tetsuo; Kitano, Masaru; Nakamura, Toshihiro

    2014-03-01

    A new method for the separate determination of Chromium(III) (Cr(III)), Chromium(VI) (Cr(VI)), and Cr(III) acetylacetonate (Cr(acac){sub 3}) in water was developed using a cation-exchange extraction disk (CED) and an anion-exchange extraction disk (AED) combined with metal furnace atomic absorption spectrometry (MFAAS). A 100-mL water sample was adjusted to pH 5.6 and passed through the CED placed on the AED. Cr(acac){sub 3} and Cr(III) were adsorbed on the CED, and Cr(VI) was adsorbed on the AED. The adsorbed Cr(acac){sub 3} was eluted with 50 mL of carbon tetrachloride, followed by the elution of Cr(III) with 50 mL of 3 mol L{sup −1} nitric acid. Cr(VI) was eluted with 50 mL of 3 mol L{sup −1} nitric acid. The chemical species of Cr eluted from the CED with carbon tetrachloride was identified as Cr(acac){sub 3} using infrared spectroscopy. The eluate of Cr(acac){sub 3} was diluted to 100 mL with carbon tetrachloride, and those of Cr(III) and Cr(VI) were diluted to 100 mL with deionized water. All of the solutions were subsequently analyzed by MFAAS. The calibration curve for the Cr(acac){sub 3} aqueous solutions exhibited good linearity in the range of 0.1 to 1 ng. The detection limit of Cr, which corresponded to three times the standard deviation (n = 10) of the blank values, was 20 pg. The recovery test for Cr(III), Cr(VI), and Cr(acac){sub 3} exhibited desirable results (96.0%–107%) when 5 μg of each species (50 μg L{sup −1}) was added to 100 mL water samples (i.e., tap water, rainwater, and bottled drinking water). In a humic acid solution, Cr(acac){sub 3} was quantitatively recovered (103%), but Cr(III) and Cr(VI) exhibited poor recoveries (i.e., 84.8% and 78.4%, respectively). - Highlights: • A determination method of Cr(III), Cr(VI), and Cr(III) acetylacetonate in water was developed. • The combination of ion-exchange resin disks with metal furnace AAS was used. • No effect of humic acid on the recovery of Cr(III) acetylacetonate was

  20. Determination of Chromium(III), Chromium(VI), and Chromium(III) acetylacetonate in water by ion-exchange disk extraction/metal furnace atomic absorption spectrometry

    A new method for the separate determination of Chromium(III) (Cr(III)), Chromium(VI) (Cr(VI)), and Cr(III) acetylacetonate (Cr(acac)3) in water was developed using a cation-exchange extraction disk (CED) and an anion-exchange extraction disk (AED) combined with metal furnace atomic absorption spectrometry (MFAAS). A 100-mL water sample was adjusted to pH 5.6 and passed through the CED placed on the AED. Cr(acac)3 and Cr(III) were adsorbed on the CED, and Cr(VI) was adsorbed on the AED. The adsorbed Cr(acac)3 was eluted with 50 mL of carbon tetrachloride, followed by the elution of Cr(III) with 50 mL of 3 mol L−1 nitric acid. Cr(VI) was eluted with 50 mL of 3 mol L−1 nitric acid. The chemical species of Cr eluted from the CED with carbon tetrachloride was identified as Cr(acac)3 using infrared spectroscopy. The eluate of Cr(acac)3 was diluted to 100 mL with carbon tetrachloride, and those of Cr(III) and Cr(VI) were diluted to 100 mL with deionized water. All of the solutions were subsequently analyzed by MFAAS. The calibration curve for the Cr(acac)3 aqueous solutions exhibited good linearity in the range of 0.1 to 1 ng. The detection limit of Cr, which corresponded to three times the standard deviation (n = 10) of the blank values, was 20 pg. The recovery test for Cr(III), Cr(VI), and Cr(acac)3 exhibited desirable results (96.0%–107%) when 5 μg of each species (50 μg L−1) was added to 100 mL water samples (i.e., tap water, rainwater, and bottled drinking water). In a humic acid solution, Cr(acac)3 was quantitatively recovered (103%), but Cr(III) and Cr(VI) exhibited poor recoveries (i.e., 84.8% and 78.4%, respectively). - Highlights: • A determination method of Cr(III), Cr(VI), and Cr(III) acetylacetonate in water was developed. • The combination of ion-exchange resin disks with metal furnace AAS was used. • No effect of humic acid on the recovery of Cr(III) acetylacetonate was observed. • The proposed method enabled the determination of three Cr

  1. Investigation of chemical modifiers for the determination of lead in fertilizers and limestone using graphite furnace atomic absorption spectrometry with Zeeman-effect background correction and slurry sampling

    Borges, Aline R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq–INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Becker, Emilene M.; Dessuy, Morgana B. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R., E-mail: mgrvale@ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq–INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq–INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil)

    2014-02-01

    In this work, chemical modifiers in solution (Pd/Mg, NH{sub 4}H{sub 2}PO{sub 4} and NH{sub 4}NO{sub 3}/Pd) were compared with permanent modifiers (Ir and Ru) for the determination of lead in fertilizer and limestone samples using slurry sampling and graphite furnace atomic absorption spectrometry with Zeeman-effect background correction. The analytical line at 283.3 nm was used due to some spectral interference observed at 217.0 nm. The NH{sub 4}H{sub 2}PO{sub 4} was abandoned due to severe spectral interference even at the 283.3-nm line. For Pd/Mg and NH{sub 4}NO{sub 3}/Pd the optimum pyrolysis and atomization temperatures were 900 °C and 1900 °C, respectively. For Ru and Ir, the integrated absorbance signal was stable up to pyrolysis temperatures of 700 °C and 900 °C, respectively, and up to atomization temperature of 1700 °C. The limit of detection (LOD) was 17 ng g{sup −1} using Pd/Mg and 29 ng g{sup −1} using NH{sub 4}NO{sub 3}/Pd. Among the permanent modifiers investigated, the LOD was 22 ng g{sup −1} Pb for Ir and 10 ng g{sup −1} Pb for Ru. The accuracy of the method was evaluated using the certified reference material NIST SRM 695. Although Ru provided lower LOD, which can be attributed to a lower blank signal, only the modifiers in solution showed concordant values of Pb concentration for the NIST SRM 695 and the most of analyzed samples. Moreover, the Pd/Mg modifier provided the highest sensitivity and for this reason it is more suitable for the determination of Pb in fertilizers samples in slurry; besides this it presented a better signal-to-noise ratio than NH{sub 4}NO{sub 3}/Pd. - Highlights: • Lead has been determined in fertilizers using slurry sampling GF AAS. • The mixture of palladium and magnesium nitrates was found to be the ideal chemical modifier. • Calibration could be carried out against aqueous standard solutions. • The proposed method is much faster than the EPA method, which includes sample digestion.

  2. Metal interferences and their removal prior to the determination of As(T) and As(III) in acid mine waters by hydride generation atomic absorption spectrometry

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Ball, James W.

    2003-01-01

    Hydride generation atomic absorption spectrometry (HGAAS) is a sensitive and selective method for the determination of total arsenic (arsenic(III) plus arsenic(V)) and arsenic(III); however, it is subject to metal interferences for acid mine waters. Sodium borohydride is used to produce arsine gas, but high metal concentrations can suppress arsine production. This report investigates interferences of sixteen metal species including aluminum, antimony(III), antimony(V), cadmium, chromium(III), chromium(IV), cobalt, copper(II), iron(III), iron(II), lead, manganese, nickel, selenium(IV), selenium(VI), and zinc ranging in concentration from 0 to 1,000 milligrams per liter and offers a method for removing interfering metal cations with cation exchange resin. The degree of interference for each metal without cation-exchange on the determination of total arsenic and arsenic(III) was evaluated by spiking synthetic samples containing arsenic(III) and arsenic(V) with the potential interfering metal. Total arsenic recoveries ranged from 92 to 102 percent for all metals tested except antimony(III) and antimony(V) which suppressed arsine formation when the antimony(III)/total arsenic molar ratio exceeded 4 or the antimony(V)/total arsenic molar ratio exceeded 2. Arsenic(III) recoveries for samples spiked with aluminum, chromium(III), cobalt, iron(II), lead, manganese, nickel, selenium(VI), and zinc ranged from 84 to 107 percent over the entire concentration range tested. Low arsenic(III) recoveries occurred when the molar ratios of metals to arsenic(III) were copper greater than 120, iron(III) greater than 70, chromium(VI) greater than 2, cadmium greater than 800, antimony(III) greater than 3, antimony(V) greater than 12, or selenium(IV) greater than 1. Low recoveries result when interfering metals compete for available sodium borohydride, causing incomplete arsine production, or when the interfering metal oxidizes arsenic(III). Separation of interfering metal cations using

  3. Determination of silver at ng mL-1 levels by preconcentration on a W-coil trap and hydride generation atomic absorption spectrometry

    Complete text of publication follows. A classical hydride generation atomic absorption spectrometry flow system consists of a reaction coil, a stripping coil, a gas liquid separator (GLS) and a heated quartz T-tube atomizer. There have been some studies for determination of Ag by using this classical hydride generation system; however, only mg L-1 levels could be determined. In this study, three types of gas-liquid separators, namely, U-shape, cylindrical and a novel large volume device were used. It was possible to determine Ag in ng mL-1 level when stripping coil was eliminated from the system. The calibration plot was linear in the range of 50 to 500 ng mL-1 using a U-shape GLS. The 3s limit of detection (LOD) is 29 ng mL-1 and characteristic concentration value, C0, were found to be 15.3 ng mL-1. The similar set-up was used also with a cylindrical GLS; it was observed that the efficiency of this GLS is about 10 fold higher than the U-shape GLS; linear working range was 5.0 to 50 ng mL-1. LOD (3s) and C0 values were found to be 3.0 ng mL-1 and 2.9 ng mL-1, respectively. In order to minimize the memory effects, a 10% (v/v) solution of dichlorodimethylsilane in toluene was used to silanize both gas liquid separators to deactivate their internal surfaces. In addition to these studies, a novel large volume GLS was used. In this device 15.0 mL of mixed acidic analyte solution and NaBH4 were placed. Argon gas was passed through this mixture for 90 seconds and formed volatile analyte species were sent to a W-coil trap heated at an optimized temperature. The calibration plot was linear between 0.10 and 0.75 ng mL-1; the LOD (3s) and C0 were found to be 0.049 ng mL-1 and 0.050 ng mL-1, respectively.

  4. Investigation of chemical modifiers for the determination of lead in fertilizers and limestone using graphite furnace atomic absorption spectrometry with Zeeman-effect background correction and slurry sampling

    In this work, chemical modifiers in solution (Pd/Mg, NH4H2PO4 and NH4NO3/Pd) were compared with permanent modifiers (Ir and Ru) for the determination of lead in fertilizer and limestone samples using slurry sampling and graphite furnace atomic absorption spectrometry with Zeeman-effect background correction. The analytical line at 283.3 nm was used due to some spectral interference observed at 217.0 nm. The NH4H2PO4 was abandoned due to severe spectral interference even at the 283.3-nm line. For Pd/Mg and NH4NO3/Pd the optimum pyrolysis and atomization temperatures were 900 °C and 1900 °C, respectively. For Ru and Ir, the integrated absorbance signal was stable up to pyrolysis temperatures of 700 °C and 900 °C, respectively, and up to atomization temperature of 1700 °C. The limit of detection (LOD) was 17 ng g−1 using Pd/Mg and 29 ng g−1 using NH4NO3/Pd. Among the permanent modifiers investigated, the LOD was 22 ng g−1 Pb for Ir and 10 ng g−1 Pb for Ru. The accuracy of the method was evaluated using the certified reference material NIST SRM 695. Although Ru provided lower LOD, which can be attributed to a lower blank signal, only the modifiers in solution showed concordant values of Pb concentration for the NIST SRM 695 and the most of analyzed samples. Moreover, the Pd/Mg modifier provided the highest sensitivity and for this reason it is more suitable for the determination of Pb in fertilizers samples in slurry; besides this it presented a better signal-to-noise ratio than NH4NO3/Pd. - Highlights: • Lead has been determined in fertilizers using slurry sampling GF AAS. • The mixture of palladium and magnesium nitrates was found to be the ideal chemical modifier. • Calibration could be carried out against aqueous standard solutions. • The proposed method is much faster than the EPA method, which includes sample digestion

  5. Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry; Determinacion de selinio en minerales y rocas por espectrometria de absorcion atomica

    Alduan, F. A.; Capdevilla, C.

    1980-07-01

    The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs.

  6. Lead determination at ng/mL level by flame atomic absorption spectrometry using a tantalum coated slotted quartz tube atom trap.

    Demirtaş, İlknur; Bakırdere, Sezgin; Ataman, O Yavuz

    2015-06-01

    Flame atomic absorption spectrometry (FAAS) still keeps its importance despite the relatively low sensitivity; because it is a simple and economical technique for determination of metals. In recent years, atom traps have been developed to increase the sensitivity of FAAS. Although the detection limit of FAAS is only at the level of µg/mL, with the use of atom traps it can reach to ng/mL. Slotted quartz tube (SQT) is one of the atom traps used to improve sensitivity. In atom trapping mode of SQT, analyte is trapped on-line in SQT for few minutes using ordinary sample aspiration, followed by the introduction of a small volume of organic solvent to effect the revolatilization and atomization of analyte species resulting in a transient signal. This system is economical, commercially available and easy to use. In this study, a sensitive analytical method was developed for the determination of lead with the help of SQT atom trapping flame atomization (SQT-AT-FAAS). 574 Fold sensitivity enhancement was obtained at a sample suction rate of 3.9 mL/min for 5.0 min trapping period with respect to FAAS. Organic solvent was selected as 40 µL of methyl isobutyl ketone (MIBK). To obtain a further sensitivity enhancement inner surface of SQT was coated with several transition metals. The best sensitivity enhancement, 1650 fold enhancement, was obtained by the Ta-coated SQT-AT-FAAS. In addition, chemical nature of Pb species trapped on quartz and Ta surface, and the chemical nature of Ta on quartz surface were investigated by X-ray photoelectron spectroscopy (XPS) and Raman Spectroscopy. Raman spectrometric results indicate that tantalum is coated on SQT surface in the form of Ta2O5. XPS studies revealed that the oxidation state of Pb in species trapped on both bare and Ta coated SQT surfaces is +2. For the accuracy check, the analyses of standard reference material were performed by use of SCP SCIENCE EnviroMAT Low (EU-L-2) and results for Pb were to be in good agreement with

  7. Improved microwave-assisted wet digestion procedures for accurate Se determination in fish and shellfish by flow injection-hydride generation-atomic absorption spectrometry

    Accurate determination of Se in biological samples, especially fish and shellfish, by hydride generation techniques has generally proven troublesome owing to the presence of organoselenium that cannot readily converted into inorganic selenium under usual oxidising conditions. Further improvements in the oxidation procedures are needed so as to obtain accurate concentration values when this type of samples is analyzed. Microwave-assisted wet digestion (MAWD) procedures of seafood based on HNO3 or the mixture HNO3/H2O2 and further thermal reduction of the Se(VI) formed to Se(IV) were evaluated. These procedures were as follows: (I) without H2O2 and without heating to dryness; (II) without H2O2 and with heating to dryness; (III) with H2O2 and without heating to dryness; (IV) with H2O2 and with heating to dryness. In general, low recoveries of selenium are obtained for several marine species (e.g., crustaceans and cephalopods), which may be ascribed to the presence of Se forms mainly associated with nonpolar proteins and lipids. Post-digestion UV irradiation proved very efficient since not only complete organoselenium decomposition was achieved but also the final step required for prereduction of Se(VI) into Se(IV) (i.e. heating at 90 deg. C for 30 min in 6 M HCl) could be avoided. With the MAWD/UV procedure, the use of strong oxidising agents (persuphate, etc.) or acids (e.g. perchloric acid) which are typically applied prior to Se determination by hydride generation techniques is overcome, and as a result, sample pre-treatment is significantly simplified. The method was successfully validated against CRM DOLT-2 (dogfish liver), CRM DORM-2 (dogfish muscle) and CRM TORT-2 (lobster hepatopancreas). Automated ultrasonic slurry sampling with electrothermal atomic absorption spectrometry was also applied for comparison. Total Se contents in ten seafood samples were established. Se levels ranged from 0.7 to 2.9 μg g-1

  8. Method development for the determination of cadmium in fertilizer samples using high-resolution continuum source graphite furnace atomic absorption spectrometry and slurry sampling

    The determination of cadmium (Cd) in fertilizers is of major interest, as this element can cause growth problems in plants, and also affect animals and humans. High-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) with charge-coupled device (CCD) array detection overcomes several of the limitations encountered with conventional line source AAS, especially the problem of accurate background measurement and correction. In this work an analytical method has been developed to determine Cd in fertilizer samples by HR-CS GF AAS using slurry sampling. Both a mixture of 10 μg Pd + 6 μg Mg in solution and 400 μg of iridium as permanent modifier have been investigated and aqueous standards were used for calibration. Pyrolysis and atomization temperatures were 600 oC and 1600 oC for the Pd-Mg modifier, and 500 deg. C and 1600 deg. C for Ir, respectively. The results obtained for Cd in the certified reference material NIST SRM 695 (Trace Elements in Multi-Nutrient Fertilizer) of 16.7 ± 1.3 μg g-1 and 16.4 ± 0.75 μg g-1 for the Pd-Mg and Ir modifier, respectively, were statistically not different from the certified value of 16.9 ± 0.2 μg g-1 on a 95% confidence level; however, the results obtained with the Ir modifier were significantly lower than those for the Pd-Mg modifier for most of the samples. The characteristic mass was 1.0 pg for the Pd-Mg modifier and 1.1 pg Cd for the Ir modifier, and the correlation coefficients (R2) of the calibration were > 0.99. The instrumental limits of detection were 7.5 and 7.9 ng g-1, and the limits of quantification were 25 and 27 ng g-1 for Pd-Mg and Ir, respectively, based on a sample mass of 5 mg. The cadmium concentration in the investigated samples was between 0.07 and 5.5 μg g-1 Cd, and hence below the maximum value of 20 μg g-1 Cd permitted by Brazilian legislation.

  9. Determination of Chromium(III), Chromium(VI), and Chromium(III) acetylacetonate in water by ion-exchange disk extraction/metal furnace atomic absorption spectrometry

    Kamakura, Nao; Inui, Tetsuo; Kitano, Masaru; Nakamura, Toshihiro

    A new method for the separate determination of Chromium(III) (Cr(III)), Chromium(VI) (Cr(VI)), and Cr(III) acetylacetonate (Cr(acac)3) in water was developed using a cation-exchange extraction disk (CED) and an anion-exchange extraction disk (AED) combined with metal furnace atomic absorption spectrometry (MFAAS). A 100-mL water sample was adjusted to pH 5.6 and passed through the CED placed on the AED. Cr(acac)3 and Cr(III) were adsorbed on the CED, and Cr(VI) was adsorbed on the AED. The adsorbed Cr(acac)3 was eluted with 50 mL of carbon tetrachloride, followed by the elution of Cr(III) with 50 mL of 3 mol L- 1 nitric acid. Cr(VI) was eluted with 50 mL of 3 mol L- 1 nitric acid. The chemical species of Cr eluted from the CED with carbon tetrachloride was identified as Cr(acac)3 using infrared spectroscopy. The eluate of Cr(acac)3 was diluted to 100 mL with carbon tetrachloride, and those of Cr(III) and Cr(VI) were diluted to 100 mL with deionized water. All of the solutions were subsequently analyzed by MFAAS. The calibration curve for the Cr(acac)3 aqueous solutions exhibited good linearity in the range of 0.1 to 1 ng. The detection limit of Cr, which corresponded to three times the standard deviation (n = 10) of the blank values, was 20 pg. The recovery test for Cr(III), Cr(VI), and Cr(acac)3 exhibited desirable results (96.0%-107%) when 5 μg of each species (50 μg L- 1) was added to 100 mL water samples (i.e., tap water, rainwater, and bottled drinking water). In a humic acid solution, Cr(acac)3 was quantitatively recovered (103%), but Cr(III) and Cr(VI) exhibited poor recoveries (i.e., 84.8% and 78.4%, respectively).

  10. High-resolution continuum source electrothermal absorption spectrometry of AlBr and CaBr for the determination of bromine

    Huang, Mao Dong; Becker-Ross, Helmut; Florek, Stefan; Heitmann, Uwe [ISAS - Institute for Analytical Sciences, Department of Interface Spectroscopy, Albert-Einstein-Str. 9, 12489 Berlin (Germany); Okruss, Michael [Gesellschaft zur Foerderung angewandter Optik, Optoelektronik, Quantenelektronik und Spektroskopie (GOS) e.V., Rudower Chaussee 29, 12489 Berlin (Germany)], E-mail: okruss@isas.de

    2008-05-15

    Molecular absorption spectra of AlBr and CaBr, produced in a graphite furnace, were investigated using a high-resolution echelle spectrometer equipped with a xenon short-arc lamp as continuum source. The analytical usability of the spectra for the determination of bromine was studied. To this end, the molecular absorptions of AlBr at 278.914 nm and CaBr at 625.315 nm were evaluated. Apart from strong absorption bands of CaF around 625.3 nm, which disturb the use of CaBr, no spectral interferences were observed for both AlBr and CaBr. Regarding chemical interference with matrix substances, the molecular absorption of AlBr and CaBr is influenced in a different way. While the sensitivity of the CaBr absorption is susceptible to chloride, aluminum, potassium and sodium ions, there is no significant effect on the AlBr absorption. In contrast, the inorganic acids (nitric, phosphoric, and sulfuric) have an influence on AlBr, but not on the CaBr molecular absorption. Therefore, the two methods complement each other and each has its own application area. Regarding real samples, a salt sample from the death sea and an organic pharmaceutical were evaluated. The results were in good agreement with those derived from two independent methods and with an existing reference value. Relative standard deviations were found in the range of 5%. The limit of detection for bromine was about 2 ng for both AlBr and CaBr molecular absorption; the dynamic range was linear at least up to 250 ng Br.

  11. Functionalization of cross linked chitosan with 2-aminopyridine-3-carboxylic acid for solid phase extraction of cadmium and zinc ions and their determination by atomic absorption spectrometry

    We have developed a new method for solid phase extraction (SPE) and preconcentration of trace amounts of cadmium and zinc using cross linked chitosan that was functionalized with 2-aminopyridine-3-carboxy acid. Analytical parameters, sample pH, effect of flow rate, sample volume, and concentration of eluent on column SPE were investigated. The effect of matrix ions on the recovery of cadmium and zinc has been investigated and were found not to interfere with preconcentration. Under the optimum experimental conditions, the preconcentration factors for Cd(II) and Zn(II) were found to be 90. The two elements were quantified via atomic absorption spectrometry. The detection limits for cadmium and zinc are 21 and 65 ng L -1, respectively. The method was evaluated by analyzing a certified reference material (NIST 1643e; water) and has been successfully applied to the analysis of cadmium and zinc in environmental water samples. (author)

  12. Synthesis of a new molecularly imprinted polymer for sorption of the silver ions from geological and antiseptic samples for determination by flame atomic absorption spectrometry.

    Hashemi-Moghaddam, Hamid; Yahyazadeh, Faegheh; Vardini, Mohammad Taghi

    2014-01-01

    A new molecularly imprinted polymer (MIP) was synthesized using methacrylic acid (functional monomer), ethylene glycol dimethacrylate (crosslinker), 2,2'-azobisisobutironitril (initiator), silver (Ag) dithizone complex (template), and chloroform (porogenic solvent). This process was a noncovalent, bulk, thermal radical-polymerization. To compare the performance of this polymer, control polymer (nonimprinted polymer) was prepared under well-defined conditions without the use of a template. Extraction experiments were performed on the MIP and a nonimprinted polymer. Then, various parameters were optimized, such as pH, time, concentration of sample, and type of eluent for elution of Ag from polymer. In addition, interfering effects were investigated on the absorption of Ag by the MIP. This polymer was used for the rapid extraction and preconcentration of Ag from an antiseptic and geological sample. Finally, the amount of Ag was measured by flame atomic absorption spectrometry after preconcentration by the synthesized MIP, and results were compared with a direct inductively coupled plasma method. The results showed high performance of this method in preconcentration of Ag. PMID:25902996

  13. Direct sample introduction of wines in graphite furnace atomic absorption spectrometry for the simultaneous determination of arsenic, cadmium, copper and lead content.

    Ajtony, Zsolt; Szoboszlai, Norbert; Suskó, Emoke Klaudia; Mezei, Pál; György, Krisztina; Bencs, László

    2008-07-30

    A multi-element graphite furnace atomic absorption spectrometry (GFAAS) method was elaborated for the simultaneous determination of As, Cd, Cu, and Pb in wine samples of various sugar contents using the transversally heated graphite atomizer (THGA) with end-capped tubes and integrated graphite platforms (IGPs). For comparative GFAAS analyses, direct injection (i.e., dispensing the sample onto the IGP) and digestion-based (i.e., adding oxidizing agents, such as HNO(3) and/or H(2)O(2) to the sample solutions) methods were optimized with the application of chemical modifiers. The mixture of 5 microg Pd (applied as nitrate) plus 3 microg Mg(NO(3))(2) chemical modifier was proven to be optimal for the present set of analytes and matrix, it allowing the optimal 600 degrees C pyrolysis and 2200 degrees C atomization temperatures, respectively. The IGP of the THGA was pre-heated at 70 degrees C to prevent the sputtering and/or foaming of sample solutions with a high organic content, dispensed together with the modifier solution, which method also improved the reproducibility of the determinations. With the digestion-based method, the recovery ranged between 87 and 122%, while with the direct injection method it was between 96 and 102% for Cd, Cu, and Pb, whereas a lower, compromise recovery of 45-85% was realized for As. The detection limits (LODs) were found to be 5.0, 0.03, 1.2, and 0.8 microg l(-1) for As, Cd, Cu, and Pb, respectively. The characteristic mass (m(0)) data were 24 pg As, 1.3 pg Cd, 13 pg Cu, and 35 pg Pb. The upper limits of the linear calibration range were 100, 2, 100, and 200 microg l(-1) for As, Cd, Cu, and Pb, respectively. The precisions were not worse than 4.8, 3.1, 3.7, and 2.3% for As, Cd, Cu, and Pb, respectively. For arsenic, a higher amount of the modifier (e.g., 20 microg Pd plus 12 microg Mg(NO(3))(2)) could be recommended to overcome the interference from the presence of sulphate and phosphate in wines. Although this method increased the

  14. Selective determination of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone by atomic-absorption spectrometry with a carbon-tube atomizer.

    Kamada, T; Yamamoto, Y

    1977-05-01

    The extraction behaviour of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone in organic solvents has been investigated by means of frameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of antimony(III) and differential determination of antimony(III) and antimony(V) have been developed. With ammonium pyrrolidinedithiocarbamate and methyl isobutyl ketone, when the aqueous phase/solvent volume ratio is 50 ml/10 ml and the injection volume in the carbon tube is 20 mul, the sensitivity for antimony is 0.2 ng/ml for 1% absorption. The relative standard deviations are ca. 2%. Interferences by many metal ions can be prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of antimony(III) and antimony(V) in various types of water. PMID:18962096

  15. A study of the physical and chemical conditions required to determine vanadium in steels by atomic absorption spectrometry also allowing the determination for copper, chromium, nickel and manganese

    In the determination of the vanadium content of a steel, the height of observation and the stoichiometry of the flame have a considerable influence. Maximum sensitivity is obtained with a height of observation of 12 mm and a reducing flame. The interactions of different cations (Na, K, Mg, Cr, Fe, Cu, Mn, Zn, La) with the vanadium depend on the nature of these cations. The various actions of hydrochloric, nitric and perchloric acids and their iron salts were studied. The results obtained relating to iron-vanadium interactions suggest possible mechanisms of the processes leading to atomisation. A proposal is made for a mixture of three salts: NH4Cl, MgCl2 and LaCl3, whose combined action makes it possible to obtain good results in the determination of the vanadium content of different types of steels. This interaction buffer also allowed the determination of the Mn, Cu, Cr and Ni contents of the same steels, without using iron compensation in the calibration ranges. (author)

  16. Determination of halogens via molecules in the air-acetylene flame using high-resolution continuum source absorption spectrometry: Part I. Fluorine

    The particular capabilities of a high-resolution continuum source absorption spectrometer were exploited to the determination of halogens in an ordinary air-acetylene flame. In the first part of the studies, a simple method was developed, which allows the determination of fluorine by measuring GaF molecular absorption. The molecules are generated in the presence of an excess of Ga in the flame. Under such conditions, all fluorine is converted into GaF, yielding an evaluable signal for the fluorine determination. Molecular bands of GaF were found between 211 and 214 nm; the strongest absorption band head at 211.248 nm was examined in detail to prove its applicability to analytical measurements. To this end, potential chemical and spectral interferences were tested, using various highly concentrated acids and metallic salt solutions. Since no serious interferences were found, the new method proved to be very reliable. As limit of detection, 1 mg L-1 fluorine in the presence of 10 g L-1 Ga was achieved, using a measurement time of five seconds. The linear dynamic range covers more than three orders of magnitude. Accuracy and precision were verified by analysis of a standard reference material (BCR No. 33)

  17. A novel separation/preconcentration system based on solidification of floating organic drop microextraction for determination of lead by graphite furnace atomic absorption spectrometry

    Dadfarnia, Shayessteh [Department of Chemistry, Yazd University, Safaieh, 89195 Yazd (Iran, Islamic Republic of)], E-mail: sdadfarnia@yazduni.ac.ir; Salmanzadeh, Ali Mohammad; Shabani, Ali Mohammad Haji [Department of Chemistry, Yazd University, Safaieh, 89195 Yazd (Iran, Islamic Republic of)

    2008-08-15

    Solidified floating organic drop microextraction (SFODME) was successfully used as a sample preparation method for graphite furnace atomic absorption spectrometry (GFAAS). 20 {mu}L of 1-undecanol containing dithizone as the chelating agent (2 x 10{sup -4} mol L{sup -1}) was transferred to the water samples containing lead ions, and the solution was stirred for the prescribed time. The sample vial was cooled in an ice bath for 5 min. The solidified extract was transferred into a conical vial where it melted immediately, and then 10 {mu}L of it was analyzed by GFAAS. Factors that influence the extraction and complex formation, such as pH, concentration of dithizone, extraction time, sample volume, and ionic strength were optimized. Under the optimized conditions, a good relative standard deviation of {+-}5.4% at 10 ng L{sup -1} and detection limit of 0.9 ng L{sup -1} were obtained. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments.

  18. Determination of arsenate in aqueous samples by precipitation of the arsenic(V)-molybdate complex with tetraphenylphosphonium chloride and neutron activation analysis or hydride generation atomic absorption spectrometry

    Elteren, J.T. van; Haselager, N.G.; Das, H.A. (Netherlands Energy Research Foundation, Petten (Netherlands)); Ligny, C.L. de; Agterdenbos, J. (Rijksuniversiteit Utrecht (Netherlands). Analytisch Chemisch Lab.)

    1991-11-05

    Precipitation of As(V) from aqueous samples is achieved by complexation of As(V) with molybdate followed by formation of an insoluble precipitate with tetraphenylphosphonium chloride (TPP{sup +}Cl{sup -}). The selectivity of the method was studied by investigating the behavior of other arsenic species (As(III), monomethylarsonic acid and dimethyl-arsinic acid) using {sup 73}As-labelled species. It follows that differen-tiation between As(V) and the methylated arsenic acids is excellent, but that some As(III) may precipitate. Combination with selective co-precipitation using dibenzyldithiocarbamate for preliminary As(III) removal yields accurate results when used with neutron activation analysis or hydride generation atomic absorption spectrometry. The competition of phosphate with As(V) for complexation with molybdate limits the use to samples with phosphate concentrations ,6 {mu}g ml{sup -1}. Results for some real water samples are presented. The results of both detection methods are in good agreement. (author). 18 refs.; 3 figs.; 5 tabs.

  19. Determination of arsenate in aqueous samples by precipitation of the arsenic(V)-molybdate complex with tetraphenylphosphonium chloride and neutron activation analysis or hydride generation atomic absorption spectrometry

    Precipitation of As(V) from aqueous samples is achieved by complexation of As(V) with molybdate followed by formation of an insoluble precipitate with tetraphenylphosphonium chloride (TPP+Cl-). The selectivity of the method was studied by investigating the behavior of other arsenic species [As(III), monomethylarsonic acid and dimethyl-arsinic acid] using 73As-labelled species. It follows that differen-tiation between As(V) and the methylated arsenic acids is excellent, but that some As(III) may precipitate. Combination with selective co-precipitation using dibenzyldithiocarbamate for preliminary As(III) removal yields accurate results when used with neutron activation analysis or hydride generation atomic absorption spectrometry. The competition of phosphate with As(V) for complexation with molybdate limits the use to samples with phosphate concentrations ,6 μg ml-1. Results for some real water samples are presented. The results of both detection methods are in good agreement. (author). 18 refs.; 3 figs.; 5 tabs

  20. A novel separation/preconcentration system based on solidification of floating organic drop microextraction for determination of lead by graphite furnace atomic absorption spectrometry

    Solidified floating organic drop microextraction (SFODME) was successfully used as a sample preparation method for graphite furnace atomic absorption spectrometry (GFAAS). 20 μL of 1-undecanol containing dithizone as the chelating agent (2 x 10-4 mol L-1) was transferred to the water samples containing lead ions, and the solution was stirred for the prescribed time. The sample vial was cooled in an ice bath for 5 min. The solidified extract was transferred into a conical vial where it melted immediately, and then 10 μL of it was analyzed by GFAAS. Factors that influence the extraction and complex formation, such as pH, concentration of dithizone, extraction time, sample volume, and ionic strength were optimized. Under the optimized conditions, a good relative standard deviation of ±5.4% at 10 ng L-1 and detection limit of 0.9 ng L-1 were obtained. The procedure was applied to tap water, well water, river water and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments

  1. Determination of lead in whole blood: Comparison of the LeadCare blood lead testing system with zeeman longitudinal electrothermal atomic absorption spectrometry

    This study compares the efficiency of blood lead level analysis by graphite furnace atomic absorption spectrometry (GFAAS) and the portable LeadCare Blood lead testing system (LCS). Recoveries of two added lead concentrations of 22 and 42 μg/dL ranged from 102.4 to 105.5% for LCS and from 96.3 to 97.2% for GFAAS. Measurement of a certified sample (Certified Danish Whole Blood) at a blood lead concentration of 26.2 μg/dL gave within- and between-run coefficients of variation which were both approximately 8% by LCS and 2% by GFAAS. Comparison of the tested method (LCS) versus GFAAS from analysis of 76 samples of blood lead collected from workers in different industrial sectors showed imperfect overall correlation (r = 0.95). The LCS is quite suitable for screening purposes, but requires the use of non-frozen blood collected less than 24 h before. Conservative threshold values should be applied when using the LCS for initial screening in the field. (orig.)

  2. Solid sampling determination of lithium and sodium additives in microsamples of yttrium oxyorthosilicate by high-resolution continuum source graphite furnace atomic absorption spectrometry

    Laczai, Nikoletta; Kovács, László; Péter, Ágnes; Bencs, László

    2016-03-01

    Solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry (SS-HR-CS-GFAAS) methods were developed and studied for the fast and sensitive quantitation of Li and Na additives in microsamples of cerium-doped yttrium oxyorthosilicate (Y2SiO5:Ce) scintillator materials. The methods were optimized for solid samples by studying a set of GFAAS conditions (i.e., the sample mass, sensitivity of the analytical lines, and graphite furnace heating programs). Powdered samples in the mass range of 0.099-0.422 mg were dispensed onto graphite sample insertion boats, weighed and analyzed. Pyrolysis and atomization temperatures were optimized by the use of single-element standard solutions of Li and Na (acidified with 0.144 mol/L HNO3) at the Li I 610.353 nm and Na I 285.3013 nm analytical lines. For calibration purposes, the method of standard addition with Li and Na solutions was applied. The correlation coefficients (R values) of the calibration graphs were not worse than 0.9678. The limit of detection for oxyorthosilicate samples was 20 μg/g and 80 μg/g for Li and Na, respectively. The alkaline content of the solid samples were found to be in the range of 0.89 and 8.4 mg/g, respectively. The accuracy of the results was verified by means of analyzing certified reference samples, using methods of standard (solution) addition calibration.

  3. Determination of calcium in hair by boiling bath digestion-flame atomic absorption spectrometry%头发中钙的沸水浴消解火焰原子吸收测定法

    过治勇; 王丰舟

    2012-01-01

    目的 建立一种简便的火焰原子吸收法测定头发中钙的方法.方法 采用沸水浴法将头发消解后用硝酸镧溶液定容,用火焰原子吸收法测定.结果 火焰原子吸收法测定头发中钙相对标准偏差为1.27%~1.72%,回收率为95.24%~103.52%,检出限为0.012μg/L.结论 火焰原子吸收法测定头发中钙简便,检出限低,精密度和准确度高,可作为测定头发中钙的方法.%[Objective]To establish a simple method for determination of calcium in hair by flame atomic absorption spectrometry. [Methods]The hair samples were digested with boiling bath method, the lanthanum nitrate solution was applied for constant volume, and the flame atomic absorption spectrometry was performed for detection. [Results] The relative standard deviation was 1.27%-1.72%, the recovery rate was 95. 24%-103. 52% , and the detection limit was 0.012 μg/L. [ Conclusion] The flame a-tomic absorption spectrometry for detecting the calcium in hair is simple, and has the advantages of low detection limit, high precision and accuracy, which can be used to determine the calcium in hair.

  4. 微波消解-石墨炉原子吸收光谱法测定儿童发铅%Microwave digestion-graphite furnace atomic absorption spectrometry for the determination of lead in children's hair

    陈宇鸿; 沈仁富

    2012-01-01

    目的:建立发中铅的微波消解-石墨炉原子吸收光谱测定法.方法:样品经微波消解后,石墨炉原子吸收光谱法测定.结果:方法标准曲线相关系数为0.9996,相对标准偏差1.15% ~2.16%,回收率为94.4% ~ 102%.结论:该法准确、灵敏,是高效、快速、实用的测定发中铅的方法.%Objective: To establish microwave digestion - graphite furnace atomic absorption spectrometry for the determination of lead in children's hair. Methods:The samples were digested with microwave oven and determined by graphite furnace atomic absorption spectrometry. Results: The correlation coefficient of the metod was 0. 9996 with RSDs of 1. 15% ~2. 16% and average recoveries of 94.4% ~ 102%. Conclusion: The method is accurate,precisive and sensitive, it is suitable for the determination of lead in hair.

  5. Development of an automated sequential injection on-line solvent extraction-back extraction procedure as demonstrated for the determination of cadmium with detection by electrothermal atomic absorption spectrometry

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection (SI) on-line solvent extraction-back extraction separation/preconcentration procedure is described. Demonstrated for the assay of cadmium by electrothermal atomic absorption spectrometry (ETAAS), the analyte is initially complexed with ammonium...

  6. A novel analytical system involving hydride generation and gold-coated W-coil trapping atomic absorption spectrometry for selenium determination at ng l-1 level

    A novel analytical technique was developed where gaseous hydrogen selenide formed by sodium tetrahydroborate reduction is transported to and trapped on a resistively heated gold-coated W-coil atom trap for in situ preconcentration. Gold coating on W-coil was prepared by using an organic solution of Au. The atom trap is held at 165 oC during the collection stage and is heated up to 675 deg. C for revolatilization; analyte species formed are transported to an externally heated quartz T-tube where the atomization takes place and the transient signal is obtained. The carrier gas consisted of 112.5 ml min-1 Ar with 75 ml min-1 H2 during the collection step and 112.5 ml min-1 Ar with 450 ml min-1 H2 in the revolatilization step. The half width of the transient signal obtained is less than 0.5 s. The RSD for the measurements was found to be 3.9% (n = 11) for 0.10 μg l-1 Se using peak height measurements. The calibration plot for 27.0 ml of sample collected in 4.0 min using a flow rate of 6.75 ml min-1 was linear between 0.13 and 2.0 μg l-1 of Se. The limit of detection (3 s) is 39 ng l-1. The enhancement factor for the characteristic concentration (Co) was found to be 20.1 when compared to conventional hydride generation atomic absorption spectrometry system without trap. In order to check the accuracy of the method, standard reference material, natural water NIST 1640 was employed; the result was found to be in good agreement with the certified value at the 95% confidence level

  7. Validation of an analytical method for the determination of total mercury in urine samples using cold vapor atomic absorption spectrometry (CV-AAS)

    Mercury (Hg) is a toxic metal applied to a variety of products and processes, representing a risk to the health of occupationally or accidentally exposed subjects. Dental amalgam is a restorative material composed of metallic mercury, which use has been widely debated in the last decades. Due to the dubiety of the studies concerning dental amalgam, many efforts concerning this issue have been conducted. The Tropical Medicine Foundation (Tocantins, Brazil) has recently initiated a study to evaluate the environmental and occupational levels of exposure to mercury in dentistry attendants at public consulting rooms in the city of Araguaina (TO). In collaboration with this study, the laboratory of analysis at IPEN's Chemistry and Environment Center is undertaking the analysis of mercury levels in exposed subjects' urine samples using cold vapor atomic absorption spectrometry. This analysis requires the definition of a methodology capable of generating reliable results. Such methodology can only be implemented after a rigorous validation procedure. As part of this work, a series of tests were conducted in order to confirm the suitability of the selected methodology and to assert that the laboratory addresses all requirements needed for a successful implementation of the methodology. The following parameters were considered in order to test the method's performance: detection and quantitation limits, selectivity, sensitivity, linearity, accuracy and precision. The assays were carried out with certified reference material, which assures the traceability of the results. Taking into account the estimated parameters, the method can be considered suitable for the afore mentioned purpose. The mercury concentration found for the reference material was of (95,12 +- 11,70)mug.L-1 with a recovery rate of 97%. The method was also applied to 39 urine samples, six of which (15%) showing urinary mercury levels above the normal limit of 10μg.L-1. The obtained results fall into a range

  8. A study of the distribution of aluminium in human placental tissues based on alkaline solubilization with determination by electrothermal atomic absorption spectrometry.

    Kruger, Pamela C; Schell, Lawrence M; Stark, Alice D; Parsons, Patrick J

    2010-09-01

    Aluminium (Al) is a nonessential element known to induce neurotoxic effects, such as dialysis dementia, in patients on hemodialysis, with compromised kidney function. The role of Al in the progression of some neurodegenerative diseases, such as Alzheimer's disease (AD), is controversial, and remains unclear. The effects of Al on other vulnerable populations, such as fetuses and infants, have been infrequently studied. In the present study, Al has been measured in human placenta samples, comprising ∼160 each of placenta bodies, placenta membranes, and umbilical cords, using electrothermal atomic absorption spectrometry (ETAAS) after atmospheric pressure digestion with tetramethylammonium hydroxide (TMAH) and ethylenediaminetetraacidic acid (EDTA). The sensitivity, or characteristic mass (m(0)), for Al at the 309.3-nm line was found to be 30 ± 4 pg. The instrumental detection limit (IDL) (3s) for Al in solution was calculated as 0.72 μg L(-1) while the method detection limit (MDL) (3s) was 0.25 μg g(-1). Accuracy was assessed through analysis of quality control (QC) materials, including certified reference materials (CRMs), in-house reference materials (RMs), and spike recovery experiments, of varying matrices. Placental tissue analyses revealed geometric mean concentrations of approximately 0.5 μg g(-1) Al in placenta bodies (n = 165) and membranes (n = 155), while Al concentrations in umbilical cords (n = 154) were about 0.3 μg g(-1). Al was detected in 95% of placenta bodies, and 81% of placenta membranes, but only in 46% of umbilical cords. PMID:21072353

  9. Determination of nickel in blood and serum samples of oropharyngeal cancer patients consumed smokeless tobacco products by cloud point extraction coupled with flame atomic absorption spectrometry.

    Arain, Sadaf Sadia; Kazi, Tasneem Gul; Arain, Jamshed Bashir; Afridi, Hassan Imran; Kazi, Atif Gul; Nasreen, Syeda; Brahman, Kapil Dev

    2014-10-01

    Oropharyngeal cancer is a significant public health issue in the world. The incidence of oropharyngeal cancer has been increased among people who have habit of chewing smokeless tobacco (SLT) in Pakistan. The aim of present study was to evaluate the concentration of nickel (Ni) in biological samples (whole blood, serum) of oral (n = 95) and pharyngeal (n = 84) male cancer patients. For comparison purposes, the biological samples of healthy age-matched referents (n = 150), who consumed and did not consumed SLT products, were also analyzed for Ni levels. As the Ni level is very low in biological samples, a preconcentration procedure has been developed, prior to analysis of analyte by flame atomic absorption spectrometry (FAAS). The Ni in acid-digested biological samples was complexed with ammonium pyrrolidinedithio carbamate (APDC), and a resulted complex was extracted in a surfactant Triton X-114. Acidic ethanol was added to the surfactant-rich phase prior to its analysis by FAAS. The chemical variables, such as pH, amounts of reagents (APDC, Triton X-114), temperature, incubation time, and sample volume were optimized. The resulted data indicated that concentration of Ni was higher in blood and serum samples of cancer patients as compared to that of referents who have or have not consumed different SLT products (p = 0.012-0.001). It was also observed that healthy referents who consumed SLT products have two to threefold higher levels of Ni in both biological samples as compared to those who were not chewing SLT products (p < 0.01). PMID:24920259

  10. Absolute number densities of helium metastable atoms determined by atomic absorption spectroscopy in helium plasma-based discharges used as ambient desorption/ionization sources for mass spectrometry

    The absolute number densities of helium atoms in the 2s 3S1 metastable state were determined in four plasma-based ambient desorption/ionization sources by atomic absorption spectroscopy. The plasmas included a high-frequency dielectric barrier discharge (HF-DBD), a low temperature plasma (LTP), and two atmospheric-pressure glow discharges, one with AC excitation and the other with DC excitation. Peak densities in the luminous plumes downstream from the discharge capillaries of the HF-DBD and the LTP were 1.39 × 1012 cm−3 and 0.011 × 1012 cm−3, respectively. Neither glow discharge produced a visible afterglow, and no metastable atoms were detected downstream from the capillary exits. However, densities of 0.58 × 1012 cm−3 and 0.97 × 1012 cm−3 were measured in the interelectrode regions of the AC and DC glow discharges, respectively. Time-resolved measurements of metastable atom densities revealed significant random variations in the timing of pulsed absorption signals with respect to the voltage waveforms applied to the discharges. - Highlights: • We determine He metastable number densities for four plasma types • The highest number densities were observed in a dielectric barrier discharge • No helium metastable atoms were observed downstream from the exits of glow discharges

  11. Evaluation of microwave digestion and solvent extraction for the determination of trace amounts of selenium in feeds and plant and animal tissues by electrothermal atomic absorption spectrometry.

    Hocquellet, P; Candillier, M P

    1991-05-01

    A sensitive method for the accurate determination of Se in agricultural products at sub-ppm levels is described. The proposed procedure involves the wet oxidation of samples by using a mixture of nitric, sulphuric and perchloric acids, co-extraction of Se and added Pd with diethylammonium N,N-diethyldithiocarbamate in chloroform, and electrothermal atomic absorption spectrometric determination of Se in the organic extract. Atomization and extraction conditions are discussed. Special attention is given to the wet oxidation step, and its advantages in speed and simplicity over conventional heating have been evaluated using an automated microwave digestion system. The results reported, obtained from several reference materials, confirm the accuracy of the method with which a detection limit of 0.002 micrograms g-1 of Se can be achieved. PMID:1877754

  12. Absorption Mode FTICR Mass Spectrometry Imaging

    Smith, D.F.; Kilgour, D.P.A.; Konijnenburg, M.; O'Connor, P.B.; Heeren, R.M.A.

    2013-01-01

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields

  13. Solid phase extraction method for the determination of lead, nickel, copper and manganese by flame atomic absorption spectrometry using sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) in water samples

    A novel column solid phase extraction procedure was developed for the determination of lead, nickel, copper and manganese in various water samples by flame atomic absorption spectrometry (FAAS) after preconcentration on sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) supported by Amberlite XAD-7. The sorbed element was subsequently eluted with 1 M nitric acid and the acid eluates are analysed by Flame atomic absorption spectrometry (FAAS). Various parameters such as pH, amount of adsorbent, eluent type and volume, flow-rate of the sample solution, volume of the sample solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH for the sorption of above mentioned metal ions was about 6.0 ± 0.2. The loading capacity of adsorbent for Pb, Cu, Ni and Mn were found to 28, 26, 22 and 20 x 10-6 g/mL, respectively. The recoveries of lead, copper, nickel and manganese under optimum conditions were found to be 96.7-99.2 at the 95% confident level. The limit of detection was 3.0, 3.2, 2.8 and 3.6 x 10-6 g/mL for lead, copper, nickel and manganese, respectively by applying a preconcentration factor 50. The proposed enrichment method was applied for metal ions in various water samples. The results were obtained are good agreement with reported method

  14. Antimony determination in seawater and pore water of marine sediments by means of coprecipitation with Mg(OH)2 and atomic absorption spectrometry

    The study of biogeochemical cycling of trace elements in inshore marine environment is of basic importance in order to understand the long-term distribution of both conventional and radioactive pollutants among the ecosystem components. Antimony is of radio- ecological interest, and its determination in some environmental matrices (seawater, pore water, biota) is always difficult from the analytical point of view. A quick method for antimony determination in seawater and interstitial water of marine sediments, by coprecipitation with Mg(OH)2 and subsequent atomic absorption measurement, is reported. Coprecipitation recovery (about 80% in optimal conditions) was evaluated using both radiotracers and the addition of known amounts of stable element, and turned out to depend on several parameters (percentage of precipitated Mg as compared to the natural content in seawater, ageing of Mg(OH)2, concomitant Fe and Mn concentrations, etc.). The total standard deviation of the proposed method is about 10%. The variance analysis showed that about 90% of total variance is due to the preconcentration procedure (sample handling and random contaminations) and only about 10% is due to the instrumental measurement. The results of antimony determinations in seawater and pore water of marine sediments collected at Montalto di Castro (Central Mediterranean Sea) are presented and discussed

  15. Application of chitosan and its N-heterocyclic derivatives for preconcentration of noble metal ions and their determination using atomic absorption spectrometry.

    Azarova, Yu A; Pestov, A V; Ustinov, A Yu; Bratskaya, S Yu

    2015-12-10

    Chitosan and its N-heterocyclic derivatives N-2-(2-pyridyl)ethylchitosan (2-PEC), N-2-(4-pyridyl) ethylchitosan (4-PEC), and N-(5-methyl-4-imidazolyl) methylchitosan (IMC) have been applied in group preconcentration of gold, platinum, and palladium for subsequent determination by atomic absorption spectroscopy (AAS) in solutions with high background concentrations of iron and sodium ions. It has been shown that the sorption mechanism, which was elucidated by XPS, significantly influences the sorption capacity of materials, the efficiency of metal ions elution after preconcentration, and, as a result, the accuracy of metal determination by AAS. We have shown that native chitosan was not suitable for preconcentration of Au(III), if the elution step was used as a part of the analysis scheme. The group preconcentration of Au(III), Pd(II), and Pt(IV) with subsequent quantitative elution using 0.1M HCl/1M thiourea solution was possible only on IMC and 4-PEC. Application of IMC for analysis of the national standard quartz ore sample proved that gold could be accurately determined after preconcentration/elution with the recovery above 80%. PMID:26428172

  16. Dispersive liquid-liquid microextraction based on solidification of floating organic drop for simultaneous separation/preconcentration of nickel, cobalt and copper prior to determination by electrothermal atomic absorption spectrometry

    Mooud Amirkavei

    2013-01-01

    Full Text Available A dispersive liquid-liquid microextraction based on solidification of floating organic drop for simultaneous extraction of trace amounts of nickel, cobalt and copper followed by their determination with electrothermal atomic absorption spectrometry was developed. 300 µL of acetone and 1-undecanol was injected into an aqueous sample containing diethyldithiocarbamate complexes of metal ions. For a sample volume of 10 mL, enrichment factors of 277, 270 and 300 and detection limits of 1.2, 1.1 and 1 ng L-1 for nickel, cobalt and copper were obtained, respectively. The method was applied to the extraction and determination of these metals in different water samples.

  17. Determination of Trace Lead and Zinc in Beers by Atomic Absorption Spectrometry after Wet Digestion%湿法消解-原子吸收光谱法测定啤酒中痕量铅和锌

    王毛兰; 赖劲虎; 周文斌

    2013-01-01

    研究了用湿法消解啤酒样品、石墨炉原子吸收光谱(GFAAS)及火焰原子吸收光谱(FAAS)法分别测定啤酒中的痕量pb2+和Zn2+.对仪器的工作参数进行了优化,探讨了混合酸消解体系、消解液用量,消解温度等因素的影响.结果表明,在200 C温度下,HNO3+HC1O4(16+4)混酸能完全消解样品.pb2+、Zn2+分别在0~80 μg/L、0~1.50 μg/mL范围内线性关系良好(线性相关系数r分别为0.9995和0.9997),其检出限分别为0.2 μg/L、8.0μg/L.测定pb2+、Zn2+的相对标准偏差(RSD)分别为1.8%和0.92%,加标回收率分别为96.5%和99.8%.该方法检出限低,精密度和准确度高,适用于啤酒样品中痕量铅、锌含量的测定.检测的9种啤酒样品中铅、锌含量范围分别为11.34~47.15 μg/L、277~422 μg/L,低于食品中的限量值.%In this paper, flame atomic absorption spectrometry and graphite furnace atomic absorption spectrometry were employed for Zn and Pb determination in beers after wet digestion. Instrument conditions of atomic absorption spectrometry were optimized and the optimal experimental conditions were selected. The effects of the type of mixed acid, the volume of digesting solution and digestion temperature were investigated. The complete digestion was performed using 16 mL of HNO3 and 4 mL of HC1O4 at 200 °C. The relative standard deviations(RSDs) of the flame atomic absorption spectrometry and graphite furnace atomic absorption spectrometry were 0. 92% and 1. 8%, respectively, and the recovery obtained for Pb and Zn were 99. 8% and 96. 5%, respectively . The methods showed linear relationship at 0-80 μg/L and 0-l. 50μg/mL for Pb and Zn, respectively. And the detection limit of Pb and Zn were 0. 2μg/L and 8. 0μg/L, respectively. The proposed method has the advantages of low detection limit,good precision and accuracy. It is suited for the determination of Pb and Zn concentrations in beers. The contents of Pb and Zn were 11. 34-47. 15

  18. Coprecipitation of trace elements with Ni2+/2-Nitroso-1-naphthol-4-sulfonic acid and their determination by flame atomic absorption spectrometry

    Ni2+/2-Nitroso-1-naphthol-4-sulfonic acid precipitate was used for the coprecipitation of Co, Pb, Cu, Fe and Zn prior to their flame atomic absorption spectrometric (FAAS) determinations in environmental samples. The precipitate could be easily dissolved with concentrated nitric acid. The recovery values for analyte ions were higher than 95%. The parameters including pH, sample volume, centrifuge time, amounts of nickel and matrix effects were optimized for the quantitative recoveries of the analytes. The relative standard deviations of cobalt, lead, copper, iron and zinc were found 4.5, 5.7, 3.8, 6.1 and 7.5%, respectively. The limit of detection was calculated as 1.05, 2.67, 1.30, 1.38, and 0.50 μg L-1 for cobalt, lead, copper, iron and zinc. The validation of the procedure was checked by the analysis of IAEA 336 lichen and SLRS 4 Riverine water standard reference materials were analyzed with satisfactory results. The presented coprecipitation procedure was successfully applied to some environmental samples for determination of analyte ions.

  19. On-line preconcentration system using a microcolumn packed with Alizarin Red S-modified alumina for zinc determination by flame atomic absorption spectrometry

    A.M. Haji Shabani

    2009-01-01

    Full Text Available A simple and sensitive on-line flow injection system for determination of zinc with FAAS has been described. The method is based on the separation and preconcentration of zinc on a microcolumn of immobilized Alizarin Red S on alumina. The adsorbed analyte is then eluted with 250 µL of nitric acid (1 mol L-1 and is transported to flame atomic absorption spectrometer for quantification. The effect of pH, sample and eluent flow rates and presence of various cations and anions on the retention of zinc was investigated. The sorption of zinc was quantitative in the pH range of 5.5-8.5. For a sample volume of 25 mL an enrichment factor of 144 and a detection limit (3S of 0.2 µg L-1 was obtained. The precision (RSD, n=7 was 3.0% at the 20 µg L-1 level. The developed system was successfully applied to the determination of zinc in water samples, hair, urine and saliva.

  20. Target characterization by PIXE, alpha spectrometry and X-ray absorption

    Kheswa, N.Y., E-mail: kheswa@tlabs.ac.za [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa); Papka, P. [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa); Department of Physics, University of Stellenbosch, Private Bag X1, 7602 Matieland (South Africa); Pineda-Vargas, C.A. [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, C.P.U.T, Bellville (South Africa); Newman, R.T. [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa)

    2011-11-01

    We report on the thickness and homogeneity characterization of thin metallic targets of Zr-96 by means of alpha absorption spectrometry, Particle Induced X-ray Emission (PIXE) and X-ray absorption. The target thicknesses determined by means of the above mentioned methods are critically compared. The thicknesses were determined before and after irradiation with a 70 MeV beam of {sup 14}N ions.

  1. A novel solidified floating organic drop microextraction method for preconcentration and determination of copper ions by flow injection flame atomic absorption spectrometry.

    Sahin, Ciğdem Arpa; Tokgöz, Ilknur

    2010-05-14

    A rapid, simple and cost effective solidified floating organic drop microextraction (SFODME) and flow injection flame atomic absorption spectrometric determination (FI-FAAS) method for copper was developed. In this method, a free microdrop of 1-undecanol containing 1,5-diphenyl carbazide (DPC) as the complexing agent was transferred to the surface of an aqueous sample including Cu(II) ions, while being agitated by a stirring bar in the bulk of the solution. Under the proper stirring conditions, the suspended microdrop can remain at the top-center position of the aqueous sample. After the completion of the extraction, the sample vial was cooled by placing it in a refrigerator for 10min. The solidified microdrop was then transferred into a conical vial, where it melted immediately and diluted to 300microL with ethanol. Finally, copper ions in 200microL of diluted solution were determined by FI-FAAS. Several factors affecting the microextraction efficiency, such as type of extraction solvent, pH, complexing agent concentration, extraction time, stirring rate, sample volume and temperature were investigated and optimized. Under optimized conditions for 100mL of solution, the preconcentration factor was 333 and the enrichment factor was 324. The limit of detection (3s) was 0.4ngmL(-1), the limit of quantification (10s) was 1.1ngmL(-1) and the relative standard deviation (RSD) for 10 replicate measurements of 10ngmL(-1) copper was 0.9%. The proposed method was successfully applied to the determination of copper in different water samples. PMID:20441870

  2. Determination of Zn by Digestion Tank Digestion and Flame Atomic Absorption Spectrometry%消解罐消解-火焰原子吸收法测定鱼肉中的锌

    陈剑杰

    2012-01-01

    [Objective]To establish a determination method of Zn in fish by digestion tank digestion and flame atomic absorption spectrometry. [Method]The fish was dissolved by digestion tank digestion, and then Zn in fish was determined by flame atomic absorption spectrometry. [Result]This method had good linear relation when the concentration range of Zn was 0-2.0 mg/L, and the correlation coefficient was 0.999 7. The detection limit of Zn was 0.002mg/mL, with the relative standard deviation of 3.12%. The recovery of Zn was 95.0%-102.5%. [ Conclusion ]The method is simole, raoid and accurate, so it is suitable for the determination of Zn in fish.%[目的]建立消解罐消解-火焰原子吸收法测定鱼肉中锌的方法。[方法]样品经消解罐消解后,用火焰原子吸收法测定样品中锌浓度。[结果]该方法在锌浓度为0-2.0mg/L范围有良好的线性关系,相关系数r=0.9997,检出限锌为0.002I.Lg/mL,相对标准偏差为3.12%,回收率锌为95.0%-102.5%。[结论]该方法具有简便、快速、准确等优点,可用于鱼肉中锌的定量检测。

  3. 微波消解--石墨炉原子吸收光谱法测定蜂胶中的微量铅%Microwave digestion - graphite furnace atomic absorption spectrometry determination of trace amounts of lead in propolis

    毛斐; 刘克克; 俎志平; 高丽红

    2015-01-01

    目的:建立微波消解---石墨炉原子吸收光谱法,用于蜂胶中铅含量的测定。方法:样品中加入硝酸进行微波消解,加入磷酸二氢铵作为基体改进剂以改善峰形和灵敏度,用石墨炉原子吸收光谱法进行铅含量的测定。结果:在优化的最佳消解条件和检测条件下,该方法具有很好的灵敏度,试验的R S D为3.1%,回收率为97.00%~101.00%,检出限为0.05m g/k g。结论:该方法操作简便,快速、检出限低、结果可靠,可用于蜂胶中铅的测定。%ObjectiveTo establish a microwave digestion - graphite furnace atomic absorption spectrometry, used for the determination of lead in propolis.MethodsMicrowave digestion sample in nitric acid, adding ammonium dihydrogen phosphate as matrix modifier to improve the sensitivity and peak shape, by graphite furnace atomic absorption spectrometry for the determination of lead content.ResultsIn the optimization of the optimum digestion conditions and testing conditions, this method has good sensitivity, test the RSD was 3.1%, the recovery is 97.0% ~ 97.0%, the detection limit of 0.05 mg/kg.ConclusionThe method is simple, fast, low detection limit, the result is reliable, can be used for the determination of lead in propolis.

  4. Flow injection determination of copper in mussels by flame atomic absorption spectrometry after on-line continuous ultrasound-assisted extraction

    Moreno-Cid, A.; Yebra, M. C.

    2002-05-01

    Copper was extracted on-line from solid mussel samples by a simple and rapid continuous ultrasound-assisted extraction system (CUES). The CUES is connected to a flow injection manifold, which permits the on-line flame atomic absorption spectrometric determination of copper. The manifold is simple and the copper signal was obtained for a volume of 250 μl of acid leachate injected into an ultrapure water carrier stream. An experimental design was used for the optimization of the continuous leaching procedure. Compared to off-line ultrasonic-assisted extraction methods, sonication time is reduced by factors of 6-12, the leaching takes place at room temperature (20 °C), and the analysis time is reduced because centrifugation was not necessary to separate the liquid phase. The method allowed a total sampling frequency of 11 samples h -1, with a relative standard deviation for the complete procedure of 2.7% (for a sample containing 2.0 μg g -1 copper (wet mass, n=11). The limit of detection was 0.06 μg g -1 (wet mass) for 30 mg of sample. The analytical procedure was verified for a reference standard material (TORT-1). The analytical procedure was applied to mussel samples from Galicia (Spain).

  5. Cloud point extraction for determination of lead in blood samples of children, using different ligands prior to analysis by flame atomic absorption spectrometry: A multivariate study

    Highlights: → Trace levels of lead in blood samples of healthy children and with different kidney disorders → Pre-concentration of Pb+2 in acid digested blood samples after chelating with two complexing reagents. → Multivariate technique was used for screening of significant factors that influence the CPE of Pb+2 → The level of Pb+2 in diseased children was significantly higher than referents of same age group. - Abstract: The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of lead (Pb2+) from digested blood samples after simultaneous complexation with ammonium pyrrolidinedithiocarbamate (APDC) and diethyldithiocarbamate (DDTC) separately. The complexed analyte was quantitatively extracted with octylphenoxypolyethoxyethanol (Triton X-114). The multivariate strategy was applied to estimate the optimum values of experimental factors. Acidic ethanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometer (FAAS). The detection limit value of Pb2+ for the preconcentration of 10 mL of acid digested blood sample was 1.14 μg L-1. The accuracy of the proposed methods was assessed by analyzing certified reference material (whole blood). Under the optimized conditions of both CPE methods, 10 mL of Pb2+ standards (10 μg L-1) complexed with APDC and DDTC, permitted the enhancement factors of 56 and 42, respectively. The proposed method was used for determination of Pb2+ in blood samples of children with kidney disorders and healthy controls.

  6. Preconcentration and determination of boron in milk, infant formula, and honey samples by solid phase extraction-electrothermal atomic absorption spectrometry

    This work presents alternative procedures for the electrothermal atomic absorption spectrometric determination of boron in milk, infant formulas, and honey samples. Honey samples (10% m/v) were diluted in a medium containing 1% v/v HNO3 and 50% v/v H2O2 and introduced in the atomizer. A mixture of 20 μg Pd and 0.5 μg Mg was used for chemical modification. Calibration was carried out using aqueous solutions prepared in the same medium, in the presence of 10% m/v sucrose. The detection limit was 2 μg g-1, equivalent to three times the standard error of the estimate (sy/x) of the regression line. For both infant formulas and milk samples, due to their very low boron content, we used a procedure based on preconcentration by solid phase extraction (Amberlite IRA 743), followed by elution with 2 mol L-1 hydrochloric acid. Detection limits were 0.03 μg g-1 for 4% m/v honey, 0.04 μg g-1 for 5% m/v infant formula and 0.08 μg mL-1 for 15% v/v cow milk. We confirmed the accuracy of the procedure by comparing the obtained results with those found via a comparable independent procedure, as well by the analysis of four certified reference materials

  7. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    Highlights: ► Synergy of ultrasound energy and TILDLME technique for improved metal extraction. ► Highly selective determination of inorganic Co species at trace levels. ► Speciation analysis of Co in several nutritional supplements with highly complex matrices. ► Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C6mim][PF6] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L−1, while the relative standard deviation (RSD) was 4.7% (at 0.5 μg L−1 Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

  8. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    Berton, Paula; Martinis, Estefania M. [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Martinez, Luis D. [INQUISAL-CONICET, Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Synergy of ultrasound energy and TILDLME technique for improved metal extraction. Black-Right-Pointing-Pointer Highly selective determination of inorganic Co species at trace levels. Black-Right-Pointing-Pointer Speciation analysis of Co in several nutritional supplements with highly complex matrices. Black-Right-Pointing-Pointer Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C{sub 6}mim][PF{sub 6}] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L{sup -1}, while the relative standard deviation (RSD) was 4.7% (at 0.5 {mu}g L{sup -1} Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

  9. Method of trivalent chromium concentration determination by atomic spectrometry

    Reheulishvili, Aleksandre N.; Tsibakhashvili, Neli Ya.

    2006-12-12

    A method is disclosed for determining the concentration of trivalent chromium Cr(III) in a sample. The addition of perchloric acid has been found to increase the atomic chromium spectrometric signal due to Cr(III), while leaving the signal due to hexavalent chromium Cr(VI) unchanged. This enables determination of the Cr(III) concentration without pre-concentration or pre-separation from chromium of other valences. The Cr(III) concentration may be measured using atomic absorption spectrometry, atomic emission spectrometry or atomic fluorescence spectrometry.

  10. AIR MONITORING BY DIFFERENTIAL OPTICAL ABSORPTION SPECTROMETRY IN BAYTOWN, TEXAS

    This report documents the results of a field study carried out in Baytown, Texas in August 1993. ne goal of the field study was to evaluate calibration and audit procedures for a differential optical absorption spectrometry (DOAS) system. he other major goal of the study was to c...

  11. Determination of As(III) and total inorganic As in water samples using an on-line solid phase extraction and flow injection hydride generation atomic absorption spectrometry

    Sigrist, Mirna, E-mail: msigrist@fiq.unl.edu.ar [Laboratorio Central, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2654-Piso 6, (3000) Santa Fe (Argentina); Albertengo, Antonela; Beldomenico, Horacio [Laboratorio Central, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2654-Piso 6, (3000) Santa Fe (Argentina); Tudino, Mabel [Laboratorio de Analisis de Trazas, Departamento de Quimica Inorganica, Analitica y Quimica Fisica/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Pabellon II, Ciudad Universitaria (1428), Buenos Aires (Argentina)

    2011-04-15

    A simple and robust on-line sequential injection system based on solid phase extraction (SPE) coupled to a flow injection hydride generation atomic absorption spectrometer (FI-HGAAS) with a heated quartz tube atomizer (QTA) was developed and optimized for the determination of As(III) in groundwater without any kind of sample pretreatment. The method was based on the selective retention of inorganic As(V) that was carried out by passing the filtered original sample through a cartridge containing a chloride-form strong anion exchanger. Thus the most toxic form, inorganic As(III), was determined fast and directly by AsH{sub 3} generation using 3.5 mol L{sup -1} HCl as carrier solution and 0.35% (m/v) NaBH{sub 4} in 0.025% NaOH as the reductant. Since the uptake of As(V) should be interfered by several anions of natural occurrence in waters, the effect of Cl{sup -}, SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, HPO{sub 4}{sup 2-}, HCO{sub 3}{sup -} on retention was evaluated and discussed. The total soluble inorganic arsenic concentration was determined on aliquots of filtered samples acidified with concentrated HCl and pre-reduced with 5% KI-5% C{sub 6}H{sub 8}O{sub 6} solution. The concentration of As(V) was calculated by difference between the total soluble inorganic arsenic and As(III) concentrations. Detection limits (LODs) of 0.5 {mu}g L{sup -1} and 0.6 {mu}g L{sup -1} for As(III) and inorganic total As, respectively, were obtained for a 500 {mu}L sample volume. The obtained limits of detection allowed testing the water quality according to the national and international regulations. The analytical recovery for water samples spiked with As(III) ranged between 98% and 106%. The sampling throughput for As(III) determination was 60 samples h{sup -1}. The device for groundwater sampling was especially designed for the authors. Metallic components were avoided and the contact between the sample and the atmospheric oxygen was carried to a minimum. On-field arsenic species

  12. Combined discrete nebulization and microextraction process for molybdenum determination by flame atomic absorption spectrometry (FAAS); Avaliacao da combinacao da nebulizacao discreta e processos de microextracao aplicados a determinacao de molibdenio por espectrometria de absorcao atomica com chama (FAAS)

    Oviedo, Jenny A.; Jesus, Amanda M.D. de; Fialho, Lucimar L.; Pereira-Filho, Edenir R., E-mail: erpf@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

    2014-04-15

    Simple and sensitive procedures for the extraction/preconcentration of molybdenum based on vortex-assisted solidified floating organic drop microextraction (VA-SFODME) and cloud point combined with flame absorption atomic spectrometry (FAAS) and discrete nebulization were developed. The influence of the discrete nebulization on the sensitivity of the molybdenum preconcentration processes was studied. An injection volume of 200 μ resulted in a lower relative standard deviation with both preconcentration procedures. Enrichment factors of 31 and 67 and limits of detection of 25 and 5 μ L{sup -1} were obtained for cloud point and VA-SFODME, respectively. The developed procedures were applied to the determination of Mo in mineral water and multivitamin samples. (author)

  13. Determination of Al, Cd, Cu, Fe in 111InCl3 radiopharmaceuticals solutions by flameless atomic absorption spectrometry: results and effects on 111In labelling of monoclonal antibodies

    Determination of trace elements in 111InCl3 solution have been carried out by flameless atomic absorption spectrometry. Five successive batches from three European companies have been analysed. The means of measured values range from 4560 to 6930 μ g L-1 for aluminium, 131 to 874 for cadmium, 49 to 300 for copper, 387 to 698 for iron. Using two molar ratio indexes, trivalent metallic traces have been compared to theoretical 111In content. The trace elements largely exceed radioactive material. As Fe and In have similar chemical properties, it results in low specific activity of radioactive complex when labeling monoclonal antibodies by 111In. Using a mathematical model, a detrimental effect of Fe trace levels has been studied. (author)

  14. 微波消解-火焰原子吸收分光光度法测定固体废物中的钡%Determination of Barium in Solid Wastes by flame Atomic Absorption Spectrometry with Microwave Digestion

    刘畅

    2014-01-01

    采用微波消解法对固体废物浸出液样品进行前处理,采用乙炔-空气火焰原子吸收法测定钡的含量,检出限为2.04mg/ L,加标回收率为94.5%,精密度为4.85%~6.81%。%Microwave digestion method was used to digest leaching solution of solid wastes and the air - acetylene flame atomic absorp-tion spectrometry was applied to determinate barium in the samples. The detection limits and was 2. 04mg/ L. The recovery and RSD were 94. 5% and 4. 85% ~ 6. 81% ,respectively.

  15. DETERMINATION OF TRACE AMOUNTS OF SELENIUM IN CORN, LETTUCE, POTATOES, SOYBEANS, AND WHEAT BY HYDRIDE GENERATION/CONDENSATION AND FLAME ATOMIC ABSORPTION SPECTROMETRY

    Because of the nutritional and toxicological significance of low selenium concentrations in agricultural crops, a procedure utilizing wet digestion followed by hydride generation/condensation-flame atomic absorption was developed for the routine analysis of selenium in different ...

  16. Application of multiwall carbon nanotubes impregnated with 5-dodecylsalicylaldoxime for on-line copper preconcentration and determination in water samples by flame atomic absorption spectrometry.

    Tobiasz, Anna; Walas, Stanisław; Soto Hernández, Arlene; Mrowiec, Halina

    2012-07-15

    The paper presents application of multiwall carbon nanotubes (MWCNTs) modified with 5-dodecylsalicylaldoxime to copper(II) flow-injection on-line preconcentration and flame atomic absorption spectrometric (FAAS) determination. Two new sorbents were obtained by impregnation of MWCNTs with Cu(II)-LIX 622(®) complex, however in the first case modification was preceded by carbon wall activation via oxidization (Cu-LIX-CNT-A sorbent), and in the second one no surface activation was performed (Cu-LIX-CNT sorbent). It was found that effective leaching of initially introduced copper and Cu(II) retained in preconcentration process could be realized with the use 7% and 5% (v/v) nitric acid, for particular sorbents. Testing the influence of loading solution pH and rate of loading on sorption it was found out that optimal range of loading solution pH was about 4.5-6.3 for activated and 6.15-6.25 for non-activated CNT. Investigation of sorption kinetics showed that the process can be described by pseudo-second order reaction model. Sorption equilibrium conditions (90% sorption) for LIX-CNT-A and LIX-CNT were obtained after 8-15min, respectively and maximum sorption capacity for the new sorbents amounted to 18.1mgg(-1) and 31.6mgg(-1), respectively. For the examined sorbents enrichment factors increased with extension of loading time up to 180s: linearly for activated and non-linearly for non-activated MWCNTs. Influence of potential interferents such as Cd(II), Zn(II), Fe(III), Mg(II) and Ca(II) ions on copper(II) sorption on the new CNT materials was examined individually and with the use of 2(5-2) factorial design. The study revealed significant interference from iron, magnesium and calcium ions at relatively high concentrations. Applicability of the proposed sorbents was tested for Cu(II) determination in various kinds of water samples and the results were compared with those obtained with the use of ICP MS as a reference technique. Copper(II) determination in two certified

  17. Cloud point extraction for determination of lead in blood samples of children, using different ligands prior to analysis by flame atomic absorption spectrometry: A multivariate study

    Shah, Faheem, E-mail: shah_ceac@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Tasneem Gul, E-mail: tgkazi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan Imran, E-mail: hassanimranafridi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Naeemullah, E-mail: khannaeemullah@ymail.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Arain, Muhammad Balal, E-mail: bilal_ku2004@yahoo.com [Department of Chemistry, University of Science and Technology, Bannu, KPK (Pakistan); Baig, Jameel Ahmed, E-mail: jab_mughal@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2011-09-15

    Highlights: {yields} Trace levels of lead in blood samples of healthy children and with different kidney disorders {yields} Pre-concentration of Pb{sup +2} in acid digested blood samples after chelating with two complexing reagents. {yields} Multivariate technique was used for screening of significant factors that influence the CPE of Pb{sup +2} {yields} The level of Pb{sup +2} in diseased children was significantly higher than referents of same age group. - Abstract: The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of lead (Pb{sup 2+}) from digested blood samples after simultaneous complexation with ammonium pyrrolidinedithiocarbamate (APDC) and diethyldithiocarbamate (DDTC) separately. The complexed analyte was quantitatively extracted with octylphenoxypolyethoxyethanol (Triton X-114). The multivariate strategy was applied to estimate the optimum values of experimental factors. Acidic ethanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometer (FAAS). The detection limit value of Pb{sup 2+} for the preconcentration of 10 mL of acid digested blood sample was 1.14 {mu}g L{sup -1}. The accuracy of the proposed methods was assessed by analyzing certified reference material (whole blood). Under the optimized conditions of both CPE methods, 10 mL of Pb{sup 2+} standards (10 {mu}g L{sup -1}) complexed with APDC and DDTC, permitted the enhancement factors of 56 and 42, respectively. The proposed method was used for determination of Pb{sup 2+} in blood samples of children with kidney disorders and healthy controls.

  18. Use of radiation sources with mercury isotopes for real-time highly sensitive and selective benzene determination in air and natural gas by differential absorption spectrometry with the direct Zeeman effect

    A new analytical portable system is proposed for the direct determination of benzene vapor in the ambient air and natural gas, using differential absorption spectrometry with the direct Zeeman effect and innovative radiation sources: capillary mercury lamps with different isotopic compositions (196Hg, 198Hg, 202Hg, 204Hg, and natural isotopic mixture). Resonance emission of mercury at a wavelength of 254 nm is used as probing radiation. The differential cross section of benzene absorption in dependence on wavelength is determined by scanning of magnetic field. It is found that the sensitivity of benzene detection is enhanced three times using lamp with the mercury isotope 204Hg in comparison with lamp, filled with the natural isotopic mixture. It is experimentally demonstrated that, when benzene content is measured at the Occupational Exposure Limit (3.2 mg/m3 for benzene) level, the interference from SO2, NO2, O3, H2S and toluene can be neglected if concentration of these gases does not exceed corresponding Occupational Exposure Limits. To exclude the mercury effect, filters that absorb mercury and let benzene pass in the gas duct are proposed. Basing on the results of our study, a portable spectrometer is designed with a multipath cell of 960 cm total path length and detection limit 0.5 mg/m3 at 1 s averaging and 0.1 mg/m3 at 30 s averaging. The applications of the designed spectrometer to measuring the benzene concentration in the atmospheric air from a moving vehicle and in natural gas are exemplified. - Highlights: • Portable benzene analyser is designed for direct benzene detection in air and gas. • Zeeman effect absorption spectrometry ensures very low benzene detection limits. • The Hg 2537 nm emission line from capillary mercury lamp is used for absorption. • The best sensitivity and selectivity is found using Hg 204 isotope light source. • Mercury influence is eliminated by using a sorption filter at the inlet

  19. Use of radiation sources with mercury isotopes for real-time highly sensitive and selective benzene determination in air and natural gas by differential absorption spectrometry with the direct Zeeman effect

    Revalde, Gita, E-mail: gitar@latnet.lv [Institute of Technical Physics, Riga Technical University, P.Valdena 3, Riga LV 1050 (Latvia); Sholupov, Sergey; Ganeev, Alexander; Pogarev, Sergey; Ryzhov, Vladimir [St. Petersburg State University, Universitetskaya nab., 7/9, St. Petersburg 199034 (Russian Federation); Skudra, Atis [Institute of Atomic Physics and Spectroscopy, University of Latvia, Skunu 4, Riga (Latvia)

    2015-08-05

    A new analytical portable system is proposed for the direct determination of benzene vapor in the ambient air and natural gas, using differential absorption spectrometry with the direct Zeeman effect and innovative radiation sources: capillary mercury lamps with different isotopic compositions ({sup 196}Hg, {sup 198}Hg, {sup 202}Hg, {sup 204}Hg, and natural isotopic mixture). Resonance emission of mercury at a wavelength of 254 nm is used as probing radiation. The differential cross section of benzene absorption in dependence on wavelength is determined by scanning of magnetic field. It is found that the sensitivity of benzene detection is enhanced three times using lamp with the mercury isotope {sup 204}Hg in comparison with lamp, filled with the natural isotopic mixture. It is experimentally demonstrated that, when benzene content is measured at the Occupational Exposure Limit (3.2 mg/m{sup 3} for benzene) level, the interference from SO{sub 2}, NO{sub 2}, O{sub 3}, H{sub 2}S and toluene can be neglected if concentration of these gases does not exceed corresponding Occupational Exposure Limits. To exclude the mercury effect, filters that absorb mercury and let benzene pass in the gas duct are proposed. Basing on the results of our study, a portable spectrometer is designed with a multipath cell of 960 cm total path length and detection limit 0.5 mg/m{sup 3} at 1 s averaging and 0.1 mg/m{sup 3} at 30 s averaging. The applications of the designed spectrometer to measuring the benzene concentration in the atmospheric air from a moving vehicle and in natural gas are exemplified. - Highlights: • Portable benzene analyser is designed for direct benzene detection in air and gas. • Zeeman effect absorption spectrometry ensures very low benzene detection limits. • The Hg 2537 nm emission line from capillary mercury lamp is used for absorption. • The best sensitivity and selectivity is found using Hg 204 isotope light source. • Mercury influence is

  20. Continuous Determination of Heavy Metals in Water by Atomic Fluorescence and Atomic Absorption Spectrometry%原子荧光和原子吸收法连续测定水中的重金属

    谢倩

    2015-01-01

    通过剖析原子荧光和原子吸收法的不同消解体系,优化实验条件,确定了原子荧光和原子吸收法连续测定水中的硒、砷、锌、铜的含量的最佳消解条件和最佳仪器测定条件。经加标回收以及标样分析,连续测定的灵敏度高,回收率在95.9%~109%之间,相对标准误差低于4.41%,操作简便快速,结果精确。%By analyzing the different digestion system of atomic fluorescence and atomic absorption method and optimizing experimental conditions, the optimal digestion conditions and the best measurement conditions of instruments for continuous determination selenium, arsenic, zinc, copper content in water by atomic fluorescence and atomic absorption spectrometry were determined.Spiking recovery and standard analysis result showed that continuous measurement had high sensitivity, and the recoveries was between 95.9% and 109%, relative standard deviation was less than 4.41%, the operation was simple, rapid and accurate.

  1. Spectrometer system using a modular echelle spectrograph and a laser-driven continuum source for simultaneous multi-element determination by graphite furnace absorption spectrometry

    Geisler, Sebastian; Okruss, Michael; Becker-Ross, Helmut; Huang, Mao Dong, E-mail: huang@isas.de; Esser, Norbert; Florek, Stefan

    2015-05-01

    A multi-element absorption spectrometer system has been developed based on a laser-driven xenon continuum source and a modular simultaneous echelle spectrograph (MOSES), which is characterized by a minimized number of optical components resulting in high optical throughput, high transmittance and high image quality. The main feature of the new optical design is the multifunction usage of a Littrow prism, which is attached on a rotation stage. It operates as an order-sorter for the echelle grating in a double-pass mode, as a fine positioning device moving the echelle spectrum on the detector, and as a forwarder to address different optical components, e.g., echelle gratings, in the setup. Using different prisms, which are mounted back to back on the rotation stage, a multitude of different spectroscopic modes like broad-range panorama observations, specific UV–VIS and NIR studies or high resolution zoom investigations of variable spectral channels can be realized. In the UV panorama mode applied in this work, MOSES has simultaneously detectable wavelength coverage from 193 nm to 390 nm with a spectral resolution λ/Δλ of 55,000 (3-pixel criterion). In the zoom mode the latter can be further increased by a factor of about two for a selectable section of the full wavelength range. The applicability and the analytical performance of the system were tested by simultaneous element determination in a graphite furnace, using eight different elements. Compared to an instrument operating in the optimized single line mode, the achieved analytical sensitivity using the panorama mode was typically a factor of two lower. Using the zoom mode for selected elements, comparable sensitivities were obtained. The results confirm the influence of the different spectral resolutions. - Highlights: • Echelle spectrometer with a full frame CCD array detector • High and variable spectral resolution from λ/Δλ of 55,000 to 95,000 • Laser-driven continuum light source

  2. Spectrometer system using a modular echelle spectrograph and a laser-driven continuum source for simultaneous multi-element determination by graphite furnace absorption spectrometry

    A multi-element absorption spectrometer system has been developed based on a laser-driven xenon continuum source and a modular simultaneous echelle spectrograph (MOSES), which is characterized by a minimized number of optical components resulting in high optical throughput, high transmittance and high image quality. The main feature of the new optical design is the multifunction usage of a Littrow prism, which is attached on a rotation stage. It operates as an order-sorter for the echelle grating in a double-pass mode, as a fine positioning device moving the echelle spectrum on the detector, and as a forwarder to address different optical components, e.g., echelle gratings, in the setup. Using different prisms, which are mounted back to back on the rotation stage, a multitude of different spectroscopic modes like broad-range panorama observations, specific UV–VIS and NIR studies or high resolution zoom investigations of variable spectral channels can be realized. In the UV panorama mode applied in this work, MOSES has simultaneously detectable wavelength coverage from 193 nm to 390 nm with a spectral resolution λ/Δλ of 55,000 (3-pixel criterion). In the zoom mode the latter can be further increased by a factor of about two for a selectable section of the full wavelength range. The applicability and the analytical performance of the system were tested by simultaneous element determination in a graphite furnace, using eight different elements. Compared to an instrument operating in the optimized single line mode, the achieved analytical sensitivity using the panorama mode was typically a factor of two lower. Using the zoom mode for selected elements, comparable sensitivities were obtained. The results confirm the influence of the different spectral resolutions. - Highlights: • Echelle spectrometer with a full frame CCD array detector • High and variable spectral resolution from λ/Δλ of 55,000 to 95,000 • Laser-driven continuum light source

  3. Pulse nebulization atomic absorption spectrometry after preconcentration from acidic media

    The possible advantages of the combination: chlorinated solvent extraction - pulse nebulization, abomic absorption spectrometry (AAS), as well as application of this method to multi-element determination of several important trace elements in biological samples is investigated. Hexamethyleneammonium hexamethylenedithiocarbamate (HMA-HMDTC) and ammonium pyrrolidinedithiocarbamate (APDC) as regents and CCl4, CHCl3, butylacetate (BuOAc) and methylisobutyl ketone (MIBK) as organic solvents are utilized. There is a tendency that CCl4 is the best solvent and MIBK - the worst. The study of extraction efficiency versus the ratio of aqueous-to-organic phase also shows the advantages of chlorinated solvents for extraction from acidic media. Better results are obtained with HMA-HMDTC as a reagent for Cu and Pb, whereas, for Cd extraction APDC gave a more efficient extraction. Chloroform shows a higher sensitivity enhancement factor, especially for volatile and/or chloride-forming elements. The extraction is successfully applied to determination of Cd, Cu and Pb in tissues of alfalfa, cabbage, carrots, onions, potatoes and wheat, as well as two standard reference materials. The results are in good agreement with the certified values

  4. Rapid accurate analysis of metal (oxide)-on-silica catalysts by atomic absorption spectrometry

    Jütte, B.A.H.G.; Heikamp, A.; Agterdenbos, J.

    1979-01-01

    The catalysts, which contain 10–60% copper, chromium, nickel and silicon, are decomposed in sealed Teflon-lined vessels and analyzed by atomic absorption spectrometry. Matrix matching and bracketing standards are applied. The RSD of a single determination is about 1% for all components.

  5. Determination of Arsenic, Mercury and Barium in herbarium mount paper using dynamic ultrasound-assisted extraction prior to atomic fluorescence and absorption spectrometry

    Lummas, S.; Ruiz-Jimenez, J.; Luque de Castro, M.D.; Colston, Belinda; Gonzalez-Rodriguez, Jose; B. Chen; W. Corns

    2011-01-01

    A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Flourescence spectrometers as detectors was developed to analyse mercury, arsenic and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimised by a multivariate approach. The optimal conditions were found to be 1% HNO3 extractant solution used at a flow rate of 1 mL min-1. The duty cycle and amplitude of the ...

  6. Sequential injection on-line matrix removal and trace metal preconcentration using a PTFE beads packed column as demonstrated for the determination of cadmium by electrothermal atomic absorption spectrometry

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    A sequential injection (SI) on-line matrix removal and trace metal preconcentration procedure by using a novel microcolumn packed with PTFE beads is described, and demonstrated for trace cadmium analysis with detection by electrothermal atomic absorption spectrometry (ETAAS). The analyte is...

  7. Selective Flow-Injection Quantification of Ultra-trace Amounts of Cr(VI) via On-line Complexation and Preconcentration with APDC Followed by Determination by Electrothermal Atomic Absorption Spectrometry

    Nielsen, Steffen; Hansen, Elo Harald

    1998-01-01

    effected by adsorption on the inner wall of a knotted reactor made from PTFE tubing. The complex is subsequently eluted with a monosegmented discrete zone of ethanol (55 mu l), and the analyte is quantified by electrothermal atomic absorption spectrometry (ETAAS). The operations of the FI-system and the...

  8. Determination of Ammonia-nitrogen in the Dyeing Wastewater by the Gas-phase Molecular Absorption Spectrometry%气相分子吸收光谱法测定印染废水中的氨氮

    徐运; 肖国起

    2011-01-01

    本文用气相分子吸收光谱法测定印染废水中的氨氮。气相分子吸收光谱法应用国内的气相分子吸收光谱仪测定印染废水中氨氮,与纳氏试剂法相比较,该方法快捷简单、受干扰小、分析精度高。%This paper introduced the gas-phase molecular absorption spectrometry for the ammonia-nitrogen in the dyeing wastewater.The gas-phase molecular absorption spectrometry applied the as-phase molecular absorption spectrophotometer device to analyze the ammonia-nitrogen in the dyeing wastewater.Compared with the Nesster's reagent colorimetric method,this method was fast,simple,less-disturbance and highly perceptive.

  9. Selection of Digestion Methods for Determining Lead in Tea With Graphite Furnace Atomic Absorption Spectrometry%石墨炉原子吸收光谱法测定茶叶中铅时消解方法的选择

    付珑

    2013-01-01

      用石墨炉原子吸收光谱法测定5种不同方法消解的茶叶中铅的含量,发现不同的消解方法对茶叶中微量元素铅的测定结果影响很大,从中也探索出测量茶叶中铅最低损耗的最佳消解条件,就是采用硝酸-高氯酸微波消解方式。方法灵敏度高,加标回收率为97.94%~101.86%,适合于茶叶中铅的日常检测。%Five different methods of digestion were used to determine the content of lead in tea with graphite furnace atomic absorption spectrometry. It’s found that various digestion procedures significantly influenced the testing results. Accordingly, an optimized digestion method, microwave-assisted nitric acid-perchloric acid digestion process was determined. The experiment results show that the method has high sensitivity;the recovery is 97.94%~101.86%;the method is suitable for daily determination of trace Pb in tea.

  10. Determination of Concentration of Nickel in tea by Graphite Furnace Atomic Absorption Spectrometry With Slurry Sampling%悬浮液进样石墨炉原子吸收法测定茶叶中镍含量

    陈江; 周李; 姚恩亲

    2011-01-01

    本文介绍了一种悬浮液进样石墨炉原子吸收光谱法测定茶叶中镍含量的方法.讨论了悬浮液制备、样品粒径、取样量、悬浮液酸度及扣背景方式等因素对测定结果的影响.经优化后,方法检出限为0.32mg/kg,精密度3.64%,回收率102%.方法简单快速,效率高,劳动强度低,是测定茶叶中镍含量的高效方法.%The method of determining the concentration of Nickle in tea by graphite furnace atomic absorption spectrometry with slurry sampling is introduced. The effects of slurry preparation, particle size of sample,sampling quantity ,acid concentration cf slurry and the mode of background deduction on the determination are studied. Under the optimized operating conditions,the detection limit of this method is 0.32 mg/kg,the RSD is 3.64% and the recovery is 102%. The advantages of simple,fast and low labor intensity indicate that it is an effective method for determining the concentration of Nickel in tea.

  11. Determination of As, Cd, Pb and Se in DORM-1 dogfish muscle reference material using alkaline solubilization and electrothermal atomic absorption spectrometry with Ir+Rh as permanent modifiers or Pd+Mg in solution

    In this work, tetramethylammonium hydroxide (TMAH) was used to solubilize the DORM-1 dogfish muscle certified reference material as a model substance for the determination of As, Cd, Pb and Se by electrothermal atomic absorption spectrometry (ET AAS). The sample was mixed with a small amount of TMAH and heated to 60 deg. C for 10 min in a water bath. After dissolution, As and Se were determined using palladium and magnesium nitrates as a chemical modifier added in solution. For Cd and Pb, best results were obtained with a mixture of 250 μg of each of iridium and rhodium as permanent modifiers. In both cases, the calibration was performed with aqueous solutions in 0.2% v/v HNO3. The temperature program for each analyte was optimized using pyrolysis and atomization curves established with the fish reference material. The detection limits in dry samples and the characteristic mass values were: Cd 0.005 μg g-1 and 0.9 pg; Pb 0.04 μg g-1 and 7.6 pg; As 0.4 μg g-1 and 13 pg and Se 0.6 μg g-1 and 20 pg, respectively. Results from the determination of these elements in the DORM-1 certified fish reference material were within the 95% confidence interval of the certified values

  12. Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

    Grijalba, Alexander Castro; Escudero, Leticia B.; Wuilloud, Rodolfo G.

    2015-08-01

    A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L- 1 and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L- 1 of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract.

  13. 微波消解-石墨炉原子吸收法测定食品中铅、镉和铜%Determination of lead, cadmium and copper in food by microwave digestion graphite furnace atomic absorption spectrometry

    李志娟; 王金星

    2012-01-01

    Objective To establish microwave digestion graphite furnace atomic absorption spectrometry method for determination lead, cadmium and copper in food. Method The food was dissolved by microwave digestion and then Pb, Cd and Cu in food were determined by graphite furnace atomic absorption spectrometry. Results This method had good linear relation at the density range of Pb O(I,g/L to 20u,g/L, Cd Op,g/L to 2p,g/L and Cu Omg/L to 0. Lmg/L, correlation coefficient were rPb = 0. 9995, rcd = 0. 9998, rCu = 0. 9992, the detection limit were that Pb 0. 005mg/kg, Cd 0. 0003 mg/kg, Cu 0. 08 mg/kg, with the relative standard deviation was that Pb 2. 3% , Cd 1. 2% , CuO.92%. The coefficient of recovery was that Pb 88. 5% ~ 93. 5% , Cd 92. 0% -96. 8% , Cu 93. 3% ~ 97. 6%. Conclusions The method is simple and rapid and accurate, it is suitable for daily determination.%目的 建立微波消解-石墨炉原子吸收法测定食品中铅、镉和铜的方法.方法 食品样品经微波消解后,用石墨炉原子吸收法测定食品中铅、镉和铜的浓度.结果 本法在铅浓度为0μg/L~20μg/L、镉浓度为0μg/L ~ 2μg/L、铜浓度为0mg/L ~0.1mg/L,范围有良好的线性关系,相关系数:rPb=0.9 995,rCd=0.9 998,rCu=0.9 992;检出限为:Pb:0.005mg/kg,Cd:0.0 003mg/kg,Cu:0.08mg/kg;相对标准偏差为Pb:2.3%,Cd:1.2%,Cu:0.92%;回收率为Pb:88.5% ~93.5%,Cd:92.0% ~96.8%,Cu:93.3%~97.6%.结论 该方法具有简便、快速、准确等优点,适合日常批量检测.

  14. Evaluation of a novel PTFE material for use as a means for separation and preconcentration of trace levels of metal ions in sequential injection (SI) and sequential injection lab-on-valve (SI-LOV) systems. Determination of cadmium (II) with detection by electrothermal atomic absorption spectrometry

    Long, Xiangbao; Chomchoei, Roongrat; Hansen, Elo Harald;

    2004-01-01

    an external packed column and in a sequential injection lab-on-valve (SI-LOV) system. Employed for the determination of cadmium(II), complexed with diethyldithiophosphate (DDPA), and detection by electrothermal atomic absorption spectrometry (ETAAS), its performance was compared to that of a...

  15. 微波消解-原子吸收法快速测定汽油中的锰铅铁%Microwave Digestion-Atomic Absorption Spectrometry for Rapid Determination of Gasoline of Mn, Pb and Fe

    张永惠; 隋之宇; 王梦迪

    2014-01-01

    The microwave digestion-atomic absorption spectrometry analysis method of manganese , lead and iron in gasoline was proposed.Gasoline samples with nitric acid and small amounts of perchlorate ( mixed acid ) do solvent after 60 ℃water bath pretreatment.In the sealed container , the sample was dissolved after pressure relief , constant volume with the atomic absorption instrument own rapid sequence analysis function and the content of manganese , and lead, iron were determined fast and efficiently.The weight , the amount of solvent , and ions of the microwave digestion sample on the analysis results were also investigated , and the measurement result was consistent with the standard value of its standard samples.This method was suitable to the determination of manganese , lead and iron in gasoline.%提出了微波消解-原子吸收法测定汽油中锰、铅、铁的分析方法。汽油样品用硝酸和少量高氯酸(混酸)做溶剂经过60℃水浴预处理后。在密闭容器中进行消解,样品溶解完毕泄压后,定容,用原子吸收仪器自有的快速序列分析功能的同时测定锰、铅、铁的含量,快速高效。同时考察了微波消解称样量、溶剂用量及共存离子对分析结果的影响,其标准样品的测定结果与标准值一致。本法适应于汽油中锰、铅、铁的测定。

  16. Use of radiation sources with mercury isotopes for real-time highly sensitive and selective benzene determination in air and natural gas by differential absorption spectrometry with the direct Zeeman effect.

    Revalde, Gita; Sholupov, Sergey; Ganeev, Alexander; Pogarev, Sergey; Ryzhov, Vladimir; Skudra, Atis

    2015-08-01

    A new analytical portable system is proposed for the direct determination of benzene vapor in the ambient air and natural gas, using differential absorption spectrometry with the direct Zeeman effect and innovative radiation sources: capillary mercury lamps with different isotopic compositions ((196)Hg, (198)Hg, (202)Hg, (204)Hg, and natural isotopic mixture). Resonance emission of mercury at a wavelength of 254 nm is used as probing radiation. The differential cross section of benzene absorption in dependence on wavelength is determined by scanning of magnetic field. It is found that the sensitivity of benzene detection is enhanced three times using lamp with the mercury isotope (204)Hg in comparison with lamp, filled with the natural isotopic mixture. It is experimentally demonstrated that, when benzene content is measured at the Occupational Exposure Limit (3.2 mg/m(3) for benzene) level, the interference from SO2, NO2, O3, H2S and toluene can be neglected if concentration of these gases does not exceed corresponding Occupational Exposure Limits. To exclude the mercury effect, filters that absorb mercury and let benzene pass in the gas duct are proposed. Basing on the results of our study, a portable spectrometer is designed with a multipath cell of 960 cm total path length and detection limit 0.5 mg/m(3) at 1 s averaging and 0.1 mg/m(3) at 30 s averaging. The applications of the designed spectrometer to measuring the benzene concentration in the atmospheric air from a moving vehicle and in natural gas are exemplified. PMID:26320799

  17. Preconcentration by coprecipitation of arsenic and tin in natural waters with a Ni-pyrrolidine dithiocarbamate complex and their direct determination by solid-sampling atomic-absorption spectrometry

    Zhang, Q. [Dept. of Material Science, Kitami Institute of Technology (Japan); Minami, H. [Instrumental Analysis Center, Kitami Institute of Technology (Japan); Inoue, S.; Atsuya, I. [Dept. of Material Science, Kitami Institute of Technology (Japan)

    2001-08-01

    A method for the determination of trace amounts of arsenic and tin in natural waters is described. Trace amounts of arsenic and tin were preconcentrated by coprecipitation with a Ni-ammonium pyrrolidine dithiocarbamate (APDC) complex. The coprecipitates obtained were directly analyzed by graphite-furnace atomic-absorption spectrometry (GFAAS) using the Ni-APDC complex solid-sampling technique. The coprecipitation conditions used for the trace amounts of arsenic and tin in natural water were investigated in detail. It was found that arsenic and tin at sub-ng mL{sup -1} levels were both coprecipitated quantitatively by Ni(PDC){sub 2} in the pH range 2-3. The concentration factors by coprecipitation reached approximately 40,000 when 2 mg nickel was added as a carrier element to 500 mL of the water sample. The proposed method has been applied to the determination of trace amounts of arsenic and tin in river water and seawater reference materials, and the detection limits for arsenic and tin, which were calculated from three times of the standard deviation of the procedural blanks, are 0.02 ng mL{sup -1} and 0.04 ng mL{sup -1}, respectively, for 500-mL volumes of water sample. (orig.)

  18. Preconcentration by coprecipitation of arsenic and tin in natural waters with a Ni-pyrrolidine dithiocarbamate complex and their direct determination by solid-sampling atomic-absorption spectrometry.

    Zhang, Q; Minami, H; Imoue, S; Atsuya, I

    2001-08-01

    A method for the determination of trace amounts of arsenic and tin in natural waters is described. Trace amounts of arsenic and tin were preconcentrated by coprecipitation with a Ni-ammonium pyrrolidine dithiocarbamate (APDC) complex. The coprecipitates obtained were directly analyzed by graphite-furnace atomic-absorption spectrometry (GFAAS) using the Ni-APDC complex solid-sampling technique. The coprecipitation conditions used for the trace amounts of arsenic and tin in natural water were investigated in detail. It was found that arsenic and tin at sub-ng mL(-1) levels were both coprecipitated quantitatively by Ni(PDC)2 in the pH range 2-3. The concentration factors by coprecipitation reached approximately 40,000 when 2 mg nickel was added as a carrier element to 500 mL of the water sample. The proposed method has been applied to the determination of trace amounts of arsenic and tin in river water and seawater reference materials, and the detection limits for arsenic and tin, which were calculated from three times of the standard deviation of the procedural blanks, are 0.02 ng mL(-1) and 0.04 ng mL(-1), respectively, for 500-mL volumes of water sample. PMID:11569865

  19. Synthesis and application of a nanoporous ion-imprinted polymer for the separation and preconcentration of trace amounts of vanadium from food samples before determination by electrothermal atomic absorption spectrometry.

    Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Dehghanpoor Frashah, Shahab

    2016-04-01

    A vanadium ion-imprinted polymer was synthesized in the presence of V(V) and N-benzoyl-N-phenyl hydroxyl amine using 4-vinyl pyridine as the monomer, ethylene glycol dimethacrylate as the cross linker and 2,2'-azobis(isobutyronitrile) as the initiator. The imprinted V(V) ions were completely removed by leaching the polymer with 5 mol/L nitric acid, and the polymer structure was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The ion-imprinted polymer was used as the sorbent in the development of the solid-phase extraction method for V(V) prior to its determination by electrothermal atomic absorption spectrometry. The maximum sorption capacity for V(V) ions was 26.7 mg/g at pH 4.0. Under the optimum conditions, for a sample volume of 150.0 mL, an enrichment factor of 289.0 and a detection limit of 6.4 ng/L were obtained. The developed method was successfully applied to the determination of vanadium in parsley, zucchini, black tea, rice, and water samples. PMID:26891590

  20. Hollow fiber based-liquid phase microextraction using ionic liquid solvent for preconcentration of lead and nickel from environmental and biological samples prior to determination by electrothermal atomic absorption spectrometry

    A simple and effective hollow fiber based-liquid phase microextraction (HF-LPME) technique by using ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate, [C6MIM][PF6], coupled with electrothermal atomic absorption spectrometry (ETAAS) was developed for the determination of lead and nickel in environmental and biological samples. Ammonium pyrroldinedithiocarbamate (APDC) was used as chelating agent. Several factors that influence the microextraction efficiency and ETAAS signal, such as pH, APDC concentration extraction time, amounts of ionic liquid, stirring rate, pyrolysis and atomization temperature were investigated and the microextraction conditions were established. In the optimum experimental conditions, the detection limits (3 s) of the method were 0.03 and 0.02 μg L-1, for Ni and Pb, respectively and corresponding relative standard deviations (0.5 μg L-1, n = 6) were 4.2% and 5%. The developed method was validated by the analysis of certified reference materials and applied to the determination of lead and nickel in real samples.

  1. Cobalt internal standard for Ni to assist the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry employing direct solid sample analysis.

    de Babos, Diego Victor; Bechlin, Marcos André; Barros, Ariane Isis; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta; de Oliveira, Silvana Ruella

    2016-05-15

    A new method is proposed for the simultaneous determination of Mo and Ni in plant materials by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS), employing direct solid sample analysis (DSS) and internal standardization (IS). Cobalt was used as internal standard to minimize matrix effects during Ni determinations, enabling the use of aqueous standards for calibration. Correlation coefficients for the calibration curves were typically better than 0.9937. The performance of the method was checked by analysis of six plant certified reference materials, and the results for Mo and Ni were in agreement with the certified values (95% confidence level, t-test). Analysis was made of different types of plant materials used as renewable sources of energy, including sugarcane leaves, banana tree fiber, soybean straw, coffee pods, orange bagasse, peanut hulls, and sugarcane bagasse. The concentrations found for Mo and Ni ranged from 0.08 to 0.63 ng mg(-1) and from 0.41 to 6.92 ng mg(-1), respectively. Precision (RSD) varied from 2.1% to 11% for Mo and from 3.7% to 10% for Ni. Limits of quantification of 0.055 and 0.074 ng were obtained for Mo and Ni, respectively. PMID:26992542

  2. 湿法消解石墨炉原子吸收光谱法测定茶叶中铅%Determination of lead in the tea by graphite furnace atomic absorption spectrometry with wet digestion

    熊开生; 谢朝新; 沈小东; 庄春龙; 李永青

    2014-01-01

    本文采用湿法消解石墨炉原子吸收光谱法测定茶叶中铅含量,分别从消解液种类、消解液用量和浸泡时间方面进行消解条件优化,从而建立适合的消解方法。茶叶样品以硝酸-高氯酸混合体系为消解液,浸泡6h,再结合石墨炉原子吸收光谱法测定,方法的精密度(RSD)为0.52%,样品加标回收率为98.6%~101.9%。%The study aimed to determine the lead in tea by using the graphite furnace atomic absorption spectrometry(GFAAS)with wet digestion. The digestion conditions were optimized separately from the digestion lfuid and soaking times and sample digestion quantity to establish the most appropriate digestion method. When HNO3-HClO4 mixed system was taken as the digestion liquid for digesting the tea samples with 6h soaking and the GFAAS was used to determine the Lead in the tea samples. The recovery was 98.6%-101.9%and the precise RSD was 0.52%.

  3. Determination of essential and toxic elements in commercial baby foods by instrumental neutron activation analysis and atomic absorption spectrometry; Determinacao dos elementos essenciais e toxicos em alimentos comerciais infantis por analise por ativacao com neutrons e espectrometria de absorcao atomica

    Vallinoto, Priscila

    2013-08-01

    The World Health Organization recommends that infants should be breast fed exclusively for at least six months after birth. After this period, it is recommended to start introducing complementary foods, in order to meet the child's nutritional, mineral and energy needs. Commercial food products for infants form an important part of the diet for many babies. Thus, it is very important that such food contains sufficient amounts of minerals. Inadequate complementary feeding is a major cause of high rates of infant malnutrition in developing countries. In this study, essential elements: Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Se and Zn and toxic elements: As, Cd, Hg levels were determined in twenty seven different commercial infant food product samples by Instrumental Neutron Activation Analysis (INAA) and Atomic Absorption Spectrometry (AAS). In order to validate both methodologies the reference material: INCT MPH-2 Mixed Polish Herbs and NIST - SRM 1577b Bovine Liver by INAA and NIST - SRM 1548th Typical Diet and NIST - SRM 1547 Peach Leaves by AAS were analyzed. The twenty seven baby food samples were acquired from Sao Paulo city supermarkets and stores. Essential and toxic elements were determined. Most of the essential element concentrations obtained were lower than the World Health Organization requirements, while concentrations of toxic elements were below the tolerable upper limit. These low essential element concentrations in these samples indicate that infants should not be fed only with commercial complementary foods. (author)

  4. Direct determination of lead in produced waters from petroleum exploration by electrothermal atomic absorption spectrometry X-ray fluorescence using Ir-W permanent modifier combined with hydrofluoric acid

    The present work reports the development of a methodology for the direct determination of lead in high saline waters derived from petroleum exploration employing electrothermal atomic absorption spectrometry with permanent Ir-W and HF as modifiers. These waters, so-called produced waters, have complex composition containing several types of organic and inorganic substances. In order to attain best conditions (highest analytical signal besides lowest background) for the methodology studies about the effect of several variables and the convenient calibration strategy were performed. Also, the efficiency of other modification approaches was evaluated. At best conditions, pyrolysis and atomization temperature were 800 and 2200 deg. C, respectively, when the modifiers cited above were utilized. Obtained results indicate that, in this kind of sample, lead can be determined by standard addition method or employing external calibration with standard solutions prepared in 0.8 mol l-1 NaCl medium. In order to evaluate the accuracy of the procedure, a recovery test was performed with six spiked samples of produced waters. The detection limit, quantification limit and the relative standard deviation in 0.8 mol l-1 NaCl were also calculated and the values are 1.5 μg l-1, 5.0 μg l-1 and 5.0% (at 10 μg l-1 level), respectively

  5. Direct determination of lead in produced waters from petroleum exploration by electrothermal atomic absorption spectrometry X-ray fluorescence using Ir-W permanent modifier combined with hydrofluoric acid

    Oliveira, Eliane P. [Departamento de Geoquimica, Universidade Federal Fluminense, Niteroi/RJ 24020-007 (Brazil); Santelli, Ricardo E. [Departamento de Geoquimica, Universidade Federal Fluminense, Niteroi/RJ 24020-007 (Brazil); Cassella, Ricardo J. [Departamento de Quimica Analitica, Universidade Federal Fluminense, Niteroi/RJ 24020-007 (Brazil)]. E-mail: cassella@vm.uff.br

    2005-07-22

    The present work reports the development of a methodology for the direct determination of lead in high saline waters derived from petroleum exploration employing electrothermal atomic absorption spectrometry with permanent Ir-W and HF as modifiers. These waters, so-called produced waters, have complex composition containing several types of organic and inorganic substances. In order to attain best conditions (highest analytical signal besides lowest background) for the methodology studies about the effect of several variables and the convenient calibration strategy were performed. Also, the efficiency of other modification approaches was evaluated. At best conditions, pyrolysis and atomization temperature were 800 and 2200 deg. C, respectively, when the modifiers cited above were utilized. Obtained results indicate that, in this kind of sample, lead can be determined by standard addition method or employing external calibration with standard solutions prepared in 0.8 mol l{sup -1} NaCl medium. In order to evaluate the accuracy of the procedure, a recovery test was performed with six spiked samples of produced waters. The detection limit, quantification limit and the relative standard deviation in 0.8 mol l{sup -1} NaCl were also calculated and the values are 1.5 {mu}g l{sup -1}, 5.0 {mu}g l{sup -1} and 5.0% (at 10 {mu}g l{sup -1} level), respectively.

  6. Study on solid phase extraction and flame atomic absorption spectrometry for the determination of some trace metals using a chromosorb 105 column and metal-1-(2-pyridylazo)-2-napthol chelates

    Complete text of publication follows. The aquatic environmental pollution by heavy metals has become a considerable problem for public and scientific concern due to their toxicity to human health. Therefore, determinations of toxic heavy metals, such as Fe(III), Zn(II), Pb(II) and Cu(II) have special importance in environmental samples. Many regulations including standard and reference methods for the determination of heavy metals have been presented. Flame atomic absorption spectrometry (FAAS) is widely used in the determination of heavy metals due to the simplicity of operation and low instrumental and operational cost. However, direct determination of ultra trace heavy metals presented in environmental samples is difficult because their amounts are mostly lower than the detection limit of instruments, and in addition to this nonsuitable matrix problems may occur. These limitations can be overcome by applying a clean up and/or preconcentration step prior to the determination step. Solid phase extraction(SPE) is one of the most efficient methods for separation and preconcentration of trace metal ions. The most simple SPE to be used in practice is based on adsorption of heavy metal ions as chelates. Thereby, in the present work, optimization studies on the retention of metal-1-(2-pyridylazo)-2-napthol (PAN) chelates throughout a column filled Chromosorb 105 resin were carried out for determination of trace metals in environmental samples by FAAS. In this work, firstly, all variables involved in the development of the preconcentration using a Chromosorb 105 column including, pH, sample and eluent volumes, sample and eluent flow rates, interfering effects, etc., were optimized to achieve the best analytical performance. The recovery values for the examined analytes higher than 95 % were obtained at pH 9.0. The preconcentration factors were over 75. The RSDs were <5 %.

  7. Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

    A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L−1 and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L−1 of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract. - Highlights: • Efficient retention and preconcentration of As by combining an IL with MWCNTs • Determination of As by ETAAS with direct injection of MWCNTs • Thermal degradation of MWCNTs in the graphite furnace of ETAAS • Highly sensitive speciation and determination of As in garlic

  8. Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

    Grijalba, Alexander Castro; Escudero, Leticia B.; Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar

    2015-08-01

    A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L{sup −1} and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L{sup −1} of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract. - Highlights: • Efficient retention and preconcentration of As by combining an IL with MWCNTs • Determination of As by ETAAS with direct injection of MWCNTs • Thermal degradation of MWCNTs in the graphite furnace of ETAAS • Highly sensitive speciation and determination of As in garlic.

  9. Determination of selenium in soils by slurry-sampling graphite-furnace atomic-absorption spectrometry with polytetrafluoroethylene as silica modifier

    Dobrowolski, R. [Maria Curie-Sklodowska Univ., Faculty of Chemistry, Lublin (Poland)

    2001-08-01

    A 6% slurry of polytetrafluoroethylene (PTFE) in 4% hydrofluoric acid and 1% nickel nitrate were used as modifiers for determination of selenium in soils by GF AAS. PTFE was used to remove silica from the soil sample, because this resulted in severe matrix effects. The temperature of fluorination, determined thermogravimetrically, was 600 C. The yield of fluorination depends on the molar ratio of PTFE/silica, particle size, and the time and temperature of fluorination. The soil samples were pretreated with a small amount of concentrated hydrofluoric acid placed directly in the cup of autosampler. The results for the determination of selenium in the reference soil materials by means of the slurry-sampling technique and use of aqueous standards are in good agreement with the certified values. (orig.)

  10. Thermal stability of sulfur-containing chelates and improvement of the sensitivity of copper, lead, and cadmium determination by nonflame atomic-absorption spectrometry

    High-temperature complexation processes in electrothermal atomizers in the presence of organic complexing matrix modifier have been studied. It is demonstrated that the pyrolysis of the modifier complex of the element under determination affects the analytical signal. It is found that the modifier efficiency is determined by the closeness the decomposition temperatures of the complexes and the reagent rather than by the absolute thermal stability of the complex in the solid phase in pyrolysis. The mechanism of transferring the analyte to the preatomization state is proposed

  11. Chromium, lead and cadmium in Danish milk products and cheese determined by Zeeman graphite furnace atomic absorption spectrometry after direct injection or pressurised ashing

    Larsen, Erik Huusfeldt; Rasmussen, L.

    1991-01-01

    A method for the direct determination of chromium in homogeneous samples of milk and milk products is described. Minimum sample handling and prevention of contamination was given priority. After injection of the sample into the graphite furnace, the sample was ashed in a stream of oxygen at 650-d...

  12. The determination of major and some minor constituents in lead zirconate-titanate compositions by x-ray fluorescence and atomic absorption spectrometry

    Willigen, van J.H.H.G.; Kruidhof, H.; Dahmen, E.A.M.F.

    1972-01-01

    An accurate X-ray fluorescence spectrometric method is described for the determination of lead, zirconium and titanium in lead zirconate-titanate ceramics. Careful matching of samples and standards by a borax fusion method resulted in a relative standard deviation of about 0.2% for the major constit

  13. A photo-oxidation procedure using UV radiation/H{sub 2}O{sub 2} for decomposition of wine samples - Determination of iron and manganese content by flame atomic absorption spectrometry

    Santos, Walter N.L. dos [Departamento de Ciencias Exatas e da Terra, Universidade do Estado da Bahia, Salvador, Bahia (Brazil); Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)], E-mail: wlopes@uneb.br; Brandao, Geovani C.; Portugal, Lindomar A.; David, Jorge M.; Ferreira, Sergio L.C. [Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)

    2009-06-15

    This paper proposes the use of photo-oxidation with UV radiation/H{sub 2}O{sub 2} as sample pretreatment for the determination of iron and manganese in wines by flame atomic absorption spectrometry (FAAS). The optimization involved the study of the following variables: pH and concentration of buffer solution, concentrated hydrogen peroxide volume and irradiation time. The evaluation of sample degradation was monitored by measuring the absorbance at the maximum wavelength of red wine (530 nm). Using the experimental conditions established during the optimization (irradiation time of 30 min, oxidant volume of 2.5 mL, pH 10, and a buffer concentration of 0.15 mol L{sup - 1}), this procedure allows the determination of iron and manganese with limits of detection of 30 and 22 {mu}g L{sup - 1}, respectively, for a 5 mL volume of digested sample. The precision levels, expressed as relative standard deviation (RSD), were 2.8% and 0.65% for iron and 2.7% and 0.54% for manganese for concentrations of 0.5 and 2.0 mg L{sup - 1}, respectively. Addition/recovery tests for evaluation of the accuracy were in the ranges of 90%-111% and 95%-107% for iron and manganese, respectively. This digestion procedure has been applied for the determination of iron and manganese in six wine samples. The concentrations varied from 1.58 to 2.77 mg L{sup - 1} for iron and from 1.30 to 1.91 mg L{sup - 1} for manganese. The results were compared with those obtained by an acid digestion procedure and determination of the elements by FAAS. There was no significant difference between the results obtained by the two methods based on a paired t-test (at 95% confidence level)

  14. A photo-oxidation procedure using UV radiation/H2O2 for decomposition of wine samples - Determination of iron and manganese content by flame atomic absorption spectrometry

    This paper proposes the use of photo-oxidation with UV radiation/H2O2 as sample pretreatment for the determination of iron and manganese in wines by flame atomic absorption spectrometry (FAAS). The optimization involved the study of the following variables: pH and concentration of buffer solution, concentrated hydrogen peroxide volume and irradiation time. The evaluation of sample degradation was monitored by measuring the absorbance at the maximum wavelength of red wine (530 nm). Using the experimental conditions established during the optimization (irradiation time of 30 min, oxidant volume of 2.5 mL, pH 10, and a buffer concentration of 0.15 mol L- 1), this procedure allows the determination of iron and manganese with limits of detection of 30 and 22 μg L- 1, respectively, for a 5 mL volume of digested sample. The precision levels, expressed as relative standard deviation (RSD), were 2.8% and 0.65% for iron and 2.7% and 0.54% for manganese for concentrations of 0.5 and 2.0 mg L- 1, respectively. Addition/recovery tests for evaluation of the accuracy were in the ranges of 90%-111% and 95%-107% for iron and manganese, respectively. This digestion procedure has been applied for the determination of iron and manganese in six wine samples. The concentrations varied from 1.58 to 2.77 mg L- 1 for iron and from 1.30 to 1.91 mg L- 1 for manganese. The results were compared with those obtained by an acid digestion procedure and determination of the elements by FAAS. There was no significant difference between the results obtained by the two methods based on a paired t-test (at 95% confidence level).

  15. Determination of Lead in Leather by Microwave Digest-Hydride Atomic Absorption Spectrometry%微波消解-氢化物原子吸收光谱法测定皮革中的铅

    蒋小良

    2012-01-01

    采用微波消解-氢化物原子吸收光谱法测定皮革制品中重金属铅的含量。优化了微波消解条件,并对硼氢化钠浓度、溶液酸度、铁氰化钾以及共存离子的干扰等条件进行了研究和选择。方法的检出限为0.036μg/L,应用此法对皮革制品进行分析,回收率在96.8%~105.6%之间。该方法具有快速、准确、干扰少等优点。%A method for determination of lead in leather and leather product by hydride generation-atomic absorption spectrometry with microwave digestion was developed.The condition of microwave digestion were optimized,and the influence factors such as concentration of NaBH4,acidity,the amount of K3Fe(CN)6 and interference of co-existing ion were investigated.The detection limit of this method was found to be 0.036 μg/L.The proposed method,when applied to analyze leather samples,gives recovery rates in the range of 96.8%-105.6%.The method is rapid,accurate and economical.

  16. Determination of Cadmium in Tea by Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry%微波消解-石墨炉原子吸收法测定茶叶中的镉含量

    殷锡峰; 何国柱; 韦勃

    2012-01-01

    采用微波消解系统处理样品,石墨炉原子吸收光谱法测定茶叶中的镉含量。结果表明:该法可以大大减少消化试剂的用量及样品的处理时间,干扰小,准确度高。镉的测定结果相对标准偏差为8.9%~12.5%,检出限为0.002 mg/kg。%Tea samples were treated with microwave digestion system.The results showed that this method cluld greatly reduce magnitude of digestant,and decrease its processing time.Cd in tea was determined by graphite furnace atomic absorption spectrometry.The method was rapid,simple and accuracy.The relative standard deviation of lead was 8.9%~12.5%,and the detection limit was 0.002 mg/kg.

  17. Can sample treatments based on advanced oxidation processes assisted by high-intensity focused ultrasound be used for toxic arsenic determination in human urine by flow-injection hydride-generation atomic absorption spectrometry?

    Correia, A; Galesio, M; Santos, H; Rial-Otero, R; Lodeiro, C; Oehmen, A; Conceição, Antonio C L; Capelo, J L

    2007-05-15

    Two advanced oxidation processes (AOPs), based on high-intensity focused ultrasound (HIFU), namely, KMnO(4)/HCl/HIFU and H(2)O(2)/HCl/HIFU are studied and compared for the determination of toxic arsenic in human urine [As(III)+As(V)+MMA+DMA] by flow-injection hydride-generation atomic absorption spectrometry (FI-HG-AAS). The KMnO(4)/HCl/HIFU procedure was found to be adequate for organic matter degradation in human urine. l-cysteine (letra minuscula) was used for As reduction to the trivalent state. The new procedure was assessed with seven urines certified in different As species. Results revealed that with KMnO(4)/HCl/HIFU plus l-cysteine the toxic arsenic can be accurately measured in human urine whilst the H(2)O(2)/HCl/HIFU procedure underestimates toxic As. DMA and MMA degradation in urine were observed, due to the effects of the ultrasonic field. Recoveries for As(III), As(V), MMA and DMA were within the certified ranges. Arsenobetaine was not degraded by the AOPs. The new procedure adheres well to the principles of analytical minimalism: (i) low reagent consumption, (ii) low reagent concentration, (iii) low waste production and (iv) low amount of time required for sample preparation and analysis. PMID:19071711

  18. Vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with solidification of floating organic droplet combined with flame atomic absorption spectrometry for the fast determination of cadmium in water samples.

    Peng, Guilong; Lu, Ying; He, Qiang; Mmereki, Daniel; Tang, Xiaohui; Zhong, Zhihui; Zhao, Xiaolong

    2016-01-01

    A novel vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction with solidification of floating organic droplet (VSLLME-SFO) was developed for the fast, simple and efficient determination of cadmium (Cd) in water samples followed by flame atomic absorption spectrometry (FAAS). In the VSLLME-SFO process, the addition of surfactant (as an emulsifier), could enhance the mass transfer from the aqueous solution into the extraction solvent. The extraction solvent could be dispersed into the aqueous phase under vigorous shaking with the vortex. In this paper, we investigated the influences of analytical parameters, including pH, extraction solvent type and its volume, surfactant type and its volume, concentration of chelating agent, salt effect and vortex time, on the extraction efficiency of Cd. Under the optimized conditions, the limit of detection was 0.16 μg/L. The analyte enrichment factor was 37.68. The relative standard deviation was 3.2% (10 μg/L, n = 10) and the calibration graph was linear, ranging from 0.5 to 30 μg/L. The proposed method was successfully applied for the analysis of ultra-trace Cd in river water and wastewater samples. PMID:27232416

  19. Application of modified nano-alumina as a solid phase extraction sorbent for the preconcentration of Cd and Pb in water and herbal samples prior to flame atomic absorption spectrometry determination

    The first study on the high efficiency of nanometer-sized γ-alumina coated with sodium dodecyl sulfate-1-(2-pyridylazo)-2-naphthol (SDS-PAN) as a new sorbent solid phase extraction (SPE) has been reported. A microcolumn packed with modified nanometer-sized alumina was used to preconcentrate and separate Cd and Pb in water and herbal samples. The metals were eluted with 2 mL HNO3 directly and detected with the detection system flame atomic absorption spectrometry (FAAS). Various influencing parameters on the separation and preconcentration of trace metals, such as pH, flow rate, sample volume, amount of sorbent, and concentration of eluent, were studied. Under the optimized operating conditions, the sorption capacities of the modified nano-γ-alumina for Cd and Pb were 11.1 and 16.4 mg g-1 respectively. With 500.0 mL sample an enrichment factor of 250 was obtained. The detection limits of this method for Cd and Pb were 0.15 and 0.17 μg L-1 and the R.S.D.s were 2.8 and 3.2% (n = 10), respectively. The proposed method has been applied to the determination of these metal ions at trace levels in certified reference materials and real samples with satisfactory results.

  20. Determination of Trace Amount of Cadmium by Atomic Absorption Spectrometry in Table Salt after Solid Phase Preconcentration Using Octadecyl Silica Membrane Disk Modified by a New Derivative of Pyridine

    Mahmood Payehghadr

    2013-01-01

    Full Text Available Silica-C18 bonded disk modified by a four-dentate Schiff base has been used for preconcentration of cadmium in table salt samples followed by flame atomic absorption spectrometry. The method is based on the adsorption of Cd on 1,2-bis(pyridin-2-ylmethylene hydrazine as Schiff base ligand on silica-C18 disk. The effects of several factors such as type and concentration of the eluent, pH of sample solution, amount of ligand, and breakthrough volume have been optimized based on one variable at a time. In optimum conditions (type of eluent, HNO3 1.0 mol/L; volume of eluent, 5.0 mL; solution pH, 9.0; breakthrough volume, 1000.0 mL, preconcentration factor of the present method is about 200. The resultant limit of detection is 5.0 μg/L. Finally, the performance of the method has been evaluated for extraction and determination of Cd (II in salt samples at milligram per liter concentration, and satisfactory results have been obtained (RSD ≤ 2.0%.

  1. Vortex-assisted ionic liquid microextraction coupled to flame atomic absorption spectrometry for determination of trace levels of cadmium in real samples

    Mahmoud Chamsaz

    2013-01-01

    Full Text Available A simple and rapid vortex assisted ionic liquid based liquid–liquid microextraction technique (VALLME was proposed for preconcentration of trace levels of cadmium. According to this method, the extraction solvent was dispersed into the aqueous samples by the assistance of vortex agitator. Cadmium preconcentration was mediated by chelation with the 8-hydroxyquinoline (oxine reagent and an IL, 1-octyl-3-methylimidazolium hexafluorophosphate ([Omim][PF6] was chosen as the extraction solvent to extract the hydrophobic complex. Several variables such as sample pH, concentration of oxine, volume of [Omim][PF6] and extraction time were investigated in details and optimum conditions were selected. Under the optimum conditions, the limit of detection (LOD was 2.9 μg L−1 for Cd (ІІ and relative standard deviation (RSD% for five replicate determinations of 125 μg L−1 was 4.1%. The method was successfully applied to the determination of cadmium in tap water, apple and rice samples.

  2. Single-step coacervate-mediated preconcentration of metals and metal-chelates in supramolecular vesicular surfactant assemblies and determination by flame atomic absorption spectrometry

    The use of ionic surfactant supramolecular aggregates is described, as means for accomplishing the concentration of analytes with different polarities using the same extraction pattern. The proposed method is based on the phase separation of an anionic surfactant through the formation of perplexed lamellar phases, allowing for the extraction of hydrated metal cations by complexation and metal-chelates by hydrophobic interactions. The data suggest that both extraction and phase separation are controlled by the presence of ionic surfactant as a function of the degree of phase divergence from the lamellar to bilayer phase. This again is determined by the composition of the phase-forming parameters, these are the surfactant concentration, the kind and amount of metallic counterparts and ionic strength. On the basis of these findings, the proposed method was successfully applied to the determination of metal species in natural waters. The limits of detection were easily brought down to the low microgram per liter levels by simply preconcentrating 10 mL of sample volume in the presence of at least 0.45% (w/v) of anionic surfactant. The method provided extraction recoveries higher than 94.0% with standard deviations well below 7.0%

  3. Dispersive liquid-liquid microextraction for the simultaneous separation of trace amounts of zinc and cadmium ions in water samples prior to flame atomic absorption spectrometry determination

    Sayed Zia Mohammadi

    2012-01-01

    Full Text Available In the proposed method, carbon tetrachloride and ethanol were used as extraction and dispersive solvents. Several factors that may be affected on the extraction process, such as extraction solvent, disperser solvent, the volume of extraction and disperser solvent, pH of the aqueous solution and extraction time were optimized. Under the optimal conditions, linearity was maintained between 1.0 ng mL-1 to 1.5 mg mL-1 for zinc and 1.0 ng mL-1 to 0.4 mg mL-1 for cadmium. The proposed method has been applied for determination of trace amount of zinc and cadmium in standard and water samples with satisfactory results.

  4. 火焰原子吸收光谱法间接测定药剂中的核黄素%Indirect determination of riboflavin in pharmaceuticals by flame atomic absorption spectrometry

    苏颖颖; 李晓红

    2011-01-01

    本文利用高碘酸钠对相邻羟基氧化作用的专属性,在一定介质中,高碘酸钠与核黄素完全反应后,过量的高碘酸的钠与硝酸铅或者硝酸铜生成沉淀,通过测定Pb或者Cu,建立了间接测定核黄素含量的方法.铅体系和铜体系测定的相对标准偏差(RSD)分别为4.8%和5.2%,检出限分别为0.6μg.mL和0.5μg·mL.用铅体系间接原子吸收光谱法测定维生素B片剂和针剂中的核黄素,测定结果与药典方法基本一致.%In the present work, a flame atomic absorption spectrometric method was developed for indirect determination of riboflavin. An excessive sodium periodate was used to react with riboflavin, and the remaining periodate was precipitated with excessive lead nitrate or copper nitrate. The precipitation, lead periodate or copper periodate formed was separated from the reaction medium by membrane filtration, and then was dissolved in 0.2 mol L-1 nitric acid following the determination of lead or copper by flame atomic absorption spectrometry. The calibration curve was linear over the range of 0. 001 ~ 0. 020 mg mL-1 and 0. 0025 ~ 0. 0500 mg mL-1; the relative standard deviation (RSD) for determination of 0. 005 mg mL-1 riboflavin was 4. 8% and 5. 2%; and the detection limit was 0. 0006 and 0. 0005 mg mL-1 , respectively, with lead or copper AAS measurement. The method was used for determination of riboflavin in Vitamin B2 tablets and injections.

  5. Flow Injection and Atomic Absorption Spectrometry (FI-AAS) -

    Hansen, Elo Harald

    1996-01-01

    absorption spectrometry (AAS). Initially with flame-AAS (fAAS) procedures, later for hydride generation (HG) techniques, and most recently in combination with electrothermal AAS (ETAAS). The common denominator for all these procedures is the inherently precise and strictly reproducible timing in FI from the......One of the advantages of the flow injection (FI) concept is that it is compatible with virtually all detection techniques. Being a versatile vehicle for enhancing the performance of the individual detection devices, the most spectacular results have possibly been obtained in conjunction with atomic...

  6. Synthesis and application of imprinted polyvinylimidazole-silica hybrid copolymer for Pb2+ determination by flow-injection thermospray flame furnace atomic absorption spectrometry

    Highlights: → Ion imprinted hybrid copolymer as selective sorbent for Pb2+ ions. → The sorbent was at least 10 times more selective than non imprinted copolymer. → A method for Pb2+ determination by TS-FF-AAS in different samples was developed. → High reusability and chemical stability of ion imprinted hybrid copolymer were observed. - Abstract: A novel ion imprinted polyvinylimidazole-silica hybrid copolymer (IIHC) was synthesized and used as a selective solid sorbent for Pb2+ ions preconcentration using an on-line solid phase extraction (SPE) system coupled to TS-FF-AAS. The ionic hybrid sorbent was prepared using 1-vinylimidazole and 3-(trimethoxysilyl)propylmethacrylate as monomers, Pb2+ ions as template, tetraethoxysilane as reticulating agent and 2,2'-azobis-isobutyronitrile as initiator. The best on-line SPE conditions concerning sorption behavior, including sample pH (6.46), buffer concentration (9.0 mmol L-1), eluent (HNO3) concentration (0.5 mol L-1) and preconcentration flow rate (4.0 mL min-1), were optimized by means of full factorial design and Doehlert matrix. The analytical curve ranged from 2.5 to 65.0 μg L-1 (r = 0.999) with limit of detection of 0.75 μg L-1; the precision (repeatability) calculated as relative standard deviation (n = 10) was 5.0 and 3.6% for Pb2+ concentration of 10.0 and 60.0 μg L-1, respectively. From on-line breakthrough curve, column capacity was 3.5 mg g-1. Preconcentration factor (PF), consumptive index (CI) and concentration efficiency (CE) were 128.0, 0.16 mL and 25.6 min-1, respectively. The selective performance of the sorbent, based on relative selectivity coefficient, was compared to NIC (non imprinted copolymer) for the binary mixture Pb2+/Cd2+, Pb2+/Cu2+ and Pb2+/Zn2+. The results showed that ion imprinted polyvinylimidazole-silica hybrid polymer had higher selectivity for Pb2+ than NIC at 64.9, 16.0 and 8.8 folds. The developed method was successfully applied for highly sensitive and selective Pb2

  7. Determination of palladium, platinum and rhodium in used automobile catalysts and active pharmaceutical ingredients using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis

    Resano, Martín; Flórez, María del Rosario; Queralt, Ignasi; Marguí, Eva

    2015-03-01

    This work investigates the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for the direct determination of Pd, Pt and Rh in two samples of very different nature. While analysis of active pharmaceutical ingredients is straightforward and it is feasible to minimize matrix effects, to the point that calibration can be carried out against aqueous standard solutions, the analysis of used automobile catalysts is more challenging requiring the addition of a chemical modifier (NH4F·HF) to help in releasing the analytes, a more vigorous temperature program and the use of a solid standard (CRM ERM®-EB504) for calibration. However, in both cases it was possible to obtain accurate results and precision values typically better than 10% RSD in a fast and simple way, while only two determinations are needed for the three analytes, since Pt and Rh can be simultaneously monitored in both types of samples. Overall, the methods proposed seem suited for the determination of these analytes in such types of samples, offering a greener and faster alternative that circumvents the traditional problems associated with sample digestion, requiring a small amount of sample only (0.05 mg per replicate for catalysts, and a few milligrams for the pharmaceuticals) and providing sufficient sensitivity to easily comply with regulations. The LODs achieved were 6.5 μg g- 1 (Pd), 8.3 μg g- 1 (Pt) and 9.3 μg g- 1 (Rh) for catalysts, which decreased to 0.08 μg g- 1 (Pd), 0.15 μg g- 1 (Pt) and 0.10 μg g- 1 (Rh) for pharmaceuticals.

  8. Differential determination of trace amounts of arsenic(III) and arsenic(V) in seawater by solid sampling atomic absorption spectrometry after preconcentration by coprecipitation with a nickel-pyrrolidine dithiocarbamate complex

    Zhang, Q.; Minami, H.; Inoue, S.; Atsuya, I

    2004-04-15

    A sensitive and accurate method for the differential determination of trace amounts of arsenic(III) and arsenic(V) in water samples was described. It was found that arsenic(III) was coprecipitated quantitatively with a Ni-ammonium pyrrolidine dithiocarbamate (APDC) complex at the pH range of 2-3, but arsenic(V) was hardly coprecipitated with the Ni-PDC complex in the same pH condition. The coprecipitates obtained were directly measured by electrothermal atomic absorption spectrometry (ETAAS) using the solid sampling technique. In order to determine trace amounts of total arsenic, sodium thiosulfate and potassium iodide were used to reduce arsenic(V) to the trivalent state in the sample solution before coprecipitation. The concentration of arsenic(V) in the sample solution could be calculated by the difference in concentration between arsenic(III) and total arsenic in the sample solution. The coprecipitation conditions for trace amounts of arsenic(III) and arsenic(V) in water samples by the Ni-PDC complex were investigated in detail. The concentration factor by coprecipitation was reached at about 40 000 when 2 mg of nickel as a carrier element was added to 500 ml of the water sample. The proposed method was successfully applied to the determination of trace amounts of arsenic(III) and arsenic(V) in seawater, and the detection limit for arsenic, which was defined as the concentration calculated from three times of the standard deviation of the procedural blanks, was 0.02 ng/ml for 500 ml portions of water sample in the proposed method.

  9. Trace elements determination in high salinity petroleum produced formation water by high-resolution continuum source graphite furnace atomic absorption spectrometry after matrix separation using Chelex-100 Registered-Sign resin

    Freire, Aline Soares [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro Sao Joao Batista s/n, Centro, Niteroi/RJ, 24020-150 (Brazil); Departamento de Quimica Analitica, Universidade Federal do Rio de Janeiro Av. Athos da Silveira Ramos 149, Centro de Tecnologia, Bloco A, Cidade Universitaria, Rio de Janeiro/RJ, 21941-909 (Brazil); Santelli, Ricardo Erthal, E-mail: santelli@iq.ufrj.br [Departamento de Geoquimica, Universidade Federal Fluminense, Outeiro Sao Joao Batista s/n, Centro, Niteroi/RJ, 24020-150 (Brazil); Departamento de Quimica Analitica, Universidade Federal do Rio de Janeiro Av. Athos da Silveira Ramos 149, Centro de Tecnologia, Bloco A, Cidade Universitaria, Rio de Janeiro/RJ, 21941-909 (Brazil)

    2012-05-15

    This study describes a procedure used for the determination of trace metals (Co, Cu, Mn, Ni and Pb) in high salinity petroleum produced formation water (PFW) employing high-resolution continuum source graphite furnace atomic absorption spectrometry for detection and Chelex-100 Registered-Sign resin for matrix elimination and analytes preconcentration. Using 15.0 mL of PFW for the separation/preconcentration, detection limits of 0.006, 0.07, 0.03, 0.08 and 0.02 {mu}g L{sup -1} were obtained for Co, Cu, Mn, Ni and Pb, respectively. The accuracy of the proposed method was evaluated by analyzing three seawater certified reference materials and by recovery tests, and the data indicate that the methodology can be successfully applied to this kind of samples. The precision values, expressed as relative standard deviation (% RSD, n = 10) for 2.0 {mu}g L{sup -1}, were found to be 3.5, 4.0, 9.0, 5.3 and 5.9 for Co, Cu, Mn, Ni and Pb, respectively. The proposed procedure was applied for the determination of these metals in medium and high salinity PFW samples obtained from Brazilian offshore petroleum exploration platforms. - Highlights: Black-Right-Pointing-Pointer Petroleum-produced formation water were analyzed for Co, Cu, Mn, Ni and Pb determination. Black-Right-Pointing-Pointer In batch analyte preconcentration/matrix separation using Chelex-100 Registered-Sign was used. Black-Right-Pointing-Pointer Detection limits between 0.006 and 0.08 {mu}g L{sup -1} were found by using HR-CS-GFAAS. Black-Right-Pointing-Pointer Trace elements characterization is possible using the developed method. Black-Right-Pointing-Pointer Maximum trace element concentrations found could support future Brazilian directives.

  10. Synthesis and application of imprinted polyvinylimidazole-silica hybrid copolymer for Pb{sup 2+} determination by flow-injection thermospray flame furnace atomic absorption spectrometry

    Teixeira Tarley, Cesar Ricardo, E-mail: tarley@uel.br [Programa de Pos-Graduacao em Quimica da Universidade Federal de Alfenas, Rua Gabriel Monteiro da Silva 700, Alfenas, MG, CEP 37130-000 (Brazil); Instituto Nacional de Ciencia e Tecnologia (INCT) de Bioanalitica, Universidade Estadual de Campinas (UNICAMP), Instituto de Quimica, Departamento de Quimica Analitica, Cidade Universitaria Zeferino Vaz s/n, Campinas, SP, CEP 13083-970 (Brazil); Departamento de Quimica, Universidade Estadual de Londrina, Rod. Celso Garcia Cid, PR 445 Km 380, Campus Universitario, Londrina, PR, CEP 86051-990 (Brazil); Nascimento Andrade, Felipe [Programa de Pos-Graduacao em Quimica da Universidade Federal de Alfenas, Rua Gabriel Monteiro da Silva 700, Alfenas, MG, CEP 37130-000 (Brazil); Midori de Oliveira, Fernanda; Zanetti Corazza, Marcela [Departamento de Quimica, Universidade Estadual de Londrina, Rod. Celso Garcia Cid, PR 445 Km 380, Campus Universitario, Londrina, PR, CEP 86051-990 (Brazil); Mendes de Azevedo, Luiz Fernando [Programa de Pos-Graduacao em Quimica da Universidade Federal de Alfenas, Rua Gabriel Monteiro da Silva 700, Alfenas, MG, CEP 37130-000 (Brazil); Gava Segatelli, Mariana [Universidade Tecnologica Federal do Parana (UTFPR), Av. dos Pioneiros 3131, Londrina, PR, CEP 86036-370 (Brazil)

    2011-10-10

    Highlights: {yields} Ion imprinted hybrid copolymer as selective sorbent for Pb{sup 2+} ions. {yields} The sorbent was at least 10 times more selective than non imprinted copolymer. {yields} A method for Pb{sup 2+} determination by TS-FF-AAS in different samples was developed. {yields} High reusability and chemical stability of ion imprinted hybrid copolymer were observed. - Abstract: A novel ion imprinted polyvinylimidazole-silica hybrid copolymer (IIHC) was synthesized and used as a selective solid sorbent for Pb{sup 2+} ions preconcentration using an on-line solid phase extraction (SPE) system coupled to TS-FF-AAS. The ionic hybrid sorbent was prepared using 1-vinylimidazole and 3-(trimethoxysilyl)propylmethacrylate as monomers, Pb{sup 2+} ions as template, tetraethoxysilane as reticulating agent and 2,2'-azobis-isobutyronitrile as initiator. The best on-line SPE conditions concerning sorption behavior, including sample pH (6.46), buffer concentration (9.0 mmol L{sup -1}), eluent (HNO{sub 3}) concentration (0.5 mol L{sup -1}) and preconcentration flow rate (4.0 mL min{sup -1}), were optimized by means of full factorial design and Doehlert matrix. The analytical curve ranged from 2.5 to 65.0 {mu}g L{sup -1} (r = 0.999) with limit of detection of 0.75 {mu}g L{sup -1}; the precision (repeatability) calculated as relative standard deviation (n = 10) was 5.0 and 3.6% for Pb{sup 2+} concentration of 10.0 and 60.0 {mu}g L{sup -1}, respectively. From on-line breakthrough curve, column capacity was 3.5 mg g{sup -1}. Preconcentration factor (PF), consumptive index (CI) and concentration efficiency (CE) were 128.0, 0.16 mL and 25.6 min{sup -1}, respectively. The selective performance of the sorbent, based on relative selectivity coefficient, was compared to NIC (non imprinted copolymer) for the binary mixture Pb{sup 2+}/Cd{sup 2+}, Pb{sup 2+}/Cu{sup 2+} and Pb{sup 2+}/Zn{sup 2+}. The results showed that ion imprinted polyvinylimidazole-silica hybrid polymer had higher

  11. Determination of spectrophotometric absorptivity by analytical ultracentrifugation

    M Senthilraja

    2011-01-01

    Full Text Available Rapid determination of the absorptivity for a recombinant IgG monoclonal antibody using the Beckman equipped with both Raleigh interference and UV absorbance optical systems. The analytical ultracentrifuge data for determining spectrophotometric absorptivities is compared to experimental data from quantitative amino acid analysis and an enzymatic digestion method.

  12. Determination of calcium content in prawn meat using microwave digestion-flame atomic absorption spectrometry%微波消解-FAAS测定虾肉中钙的质量分数

    马海霞; 杨贤庆; 杨燕

    2011-01-01

    The calcium content in prawn meat was determined by using microwave digestion-flame atomic absorption spectrometry ( FAAS) , and the optimal conditions of microwave digestion and FAAS program were studied. The results show that the optimal amount of digestion reagent HNO3 is 5. 0 mL when the sampling amount of prawn meat is 0. 500 g. The optimal microwave digestion program for calcium determination in prawn meat is multistep digestion process D, which includes 3 steps: 1) power400 W, ratio 100% , heat-up time 5 min, digestion temperature 120 ℃ for 5 min; 2) power 800 W, ratio 100% , heat-up time 5 min, digestion temperature 150 ℃ for 10 min; 3) power 800 W, ratio 100% , heat-up time 10 min, and digestion temperature 180 ℃ for 10 min. The calcium content in microwave-digested solution remains stable within 48 h. Under those conditions, the relative standard deviation ( RSD) of determination is 5. 284% , and the recovery of calcium is 91% ~98%. The microwave digestion-FAAS method is rapid, accurate, economical and safe in determining the calcium content in prawn meat%采用微波消解-火焰原子吸收光谱法(flame atomic absorption spectrometry,FAAS)测定虾肉中钙(Ca)元素的质量分数,对微波消解前处理的条件进行了研究.试验结果显示,最佳的微波消解体系为取样量0.500 g,以硝酸( HNO3)作为消解溶剂,用量5.0 mL,最适微波消解程序为多步消解程序D,包含3个步骤:1)功率400W,比例100%,升温5 min,消解温度120℃,保持5 min;2)功率800 W,比例100%,升温5 min,消解温度150℃,保持10 min;3)功率800 W,比例100%,升温10 min,消解温度180℃,保持10 min.样品消解液在常温或冷藏条件下保存48 h之内的稳定性良好.经微波消解前处理后虾肉样品中w(Ca)的相对标准偏差(relative standard deviation,RSD)为5.284%,加标回收率为91%~98%.微波消解-FAAS测定虾肉中的w(Ca)具有样品处理时间短、试剂用量少、结果准确和安全性高等优点.

  13. 高分辨连续光源原子吸收光谱法测定煤中硫%Determination of sulphur in coal by high resolution atomic absorption spectrometry with continuum light source

    汪雨; 任敏; 陈舜琮

    2011-01-01

    提出一种用HNO3、HClO4和HF消解样品、高分辨连续光源原子吸收光谱法测定硫在富燃空气-乙炔火焰中形成的CS双原子分子的吸收来测定煤中硫的新方法.实验用含硫标准溶液和煤的标准物质优化了仪器条件,并用不同混合酸对煤样的消解方法进行了比较.对可能存在的光谱和化学干扰、有机溶剂对硫的化合物CS吸收的影响进行了研究.结果表明:除了Fe 258.045 nm线与CS 258.056 nm线的波长差小于0.015 nm外,其他元素干扰线与CS线的波长差均大于0.015 nm,因此可以通过仪器的高分辨率使这些干扰线与CS线分开,克服干扰;Fe 258.045谱线虽然不能与CS 258.056 nm谱线完全分离,但是该谱线在富燃乙炔空气火焰中的吸收强度很弱,不能形成真正的干扰;Pb与溶液中的SO42-反应产生Pb-SO4沉淀降低了CS的吸收,可在溶液中加入乙酸铵溶液,使SO42-从PbSO4沉淀中释放出来而消除铅的干扰;HNO3、HClO4对CS的吸收影响不明显;在研究的甲醇、乙醇、乙酸、乙腈和丙酮5种有机溶剂中,只有乙醇对CS吸收有较显著的抑制作用,丙酮和乙腈能显著提高CS的吸收.对于CS 3条吸收线(257.594,258.056,257.961 nm),硫校准曲线的线性范围均为50~1 000mg/L,检出限分别为34mg/L,21 mg/L,12 mg/L.本方法用于煤标准物质和煤层样品中硫的测定,测定值与认定值相符,测定结果的相对标准偏差在0.053%~0.082%间(n=5).%The sample was digested with HNO3, HC1O4 and HF. A new method of determining sulphur in coal by high resolution atomic absorption spectrometry with continuum light source based on the measurement the absorption of CS diatomic molecule formed in fuel-rich air and ethyne flame was proposed. The instrumental conditions were optimized using sulphur-bearing standard solution and certified reference materials of coal. The digestion methods of coal sample with different acid mixtures were compared. The

  14. Cloud point extraction and flame atomic absorption spectrometry determination fo trace lead in urine%浊点萃取-火焰原子吸收光谱法测定人尿液中的痕量铅

    杜军良; 杨双; 胡杨; 王秀峰

    2014-01-01

    A method for the determination of Pb in urine by flame atomic absorption spectrometry with cloud point extraction was es-tablished. Dithizone-acetone was selected as the complex reagent and TritonX-100 as the surfactant. Effects of pH concentrations of surfactant and complex reagent equilibrium temperature and time on the efficiency and sensitivity for clound point extraction were investigated. Under optimal conditions the detection limit was 0. 06 μg·L-1(n=11)with linear over the concentration range of 0~1. 00 μg·mL-1 ,and values of recovery were in the range of 96. 7% ~101%. The present method was applied to the determination of trace lead in urine samples with satisfactory results.%以双硫腙作为络合剂、聚乙二醇辛基苯基醚( TritonX-100)为非离子表面活性剂,建立浊点萃取-火焰原子吸收光谱测定尿液中痕量铅的方法。探讨了络合剂用量、平衡时间、pH值、TritonX-100用量、冰浴时间等因素对萃取效率的影响。结果表明:该方法对铅的最大富集倍数约为40倍,检出限为0.06μg·L-1( n=11)。回收率在96.7%~101%,线性范围为0~1.00μg·mL-1。利用该方法测定尿液中痕量铅的含量,结果令人满意。

  15. Determination of trace lead in beer by cloud point extraction-flame absorption spectrometry%浊点萃取-火焰原子吸收光谱法测定啤酒中痕量铅

    杜军良; 黄静; 胡杨; 王秀峰

    2013-01-01

    Abstraet:A new method for determination of trace lead in beer by flame atomic absorption spectrometry combined with cloud point extraction was developed.The cloud point extraction system was based on TritonX-100 as surfactant and Dithizone as complexing agent.The parameters affecting cloud point extraction,including pH,extraction temperature and time,dosage of extraction agent and complexing agent were investigated and optimized.Under the optimum conditions,a good linearity was observed for lead in the range of 100~800μg/L with the detection limit of 3.25μg/LThe recovery was in the range of 95.9%~98.7%.The method was rapid,accurate,simple and was applied to the determination of lead in beer.%研究了以双硫腙作为络合剂、聚乙二醇辛基苯基醚(TritonX-100)为萃取剂的浊点萃取-火焰原子吸收光谱法(CPE-FAAS)测定酒中痕量铅的方法.研究了pH、平衡温度和平衡时间、络合剂用量、萃取剂用量和共存离子干扰等对萃取效果的影响.方法线性范围为l00~800μg/L,检出限为3.25 μg/L,回收率在95.9% ~98.7%之间.方法简单、安全、快捷、灵敏、高效,适于啤酒中痕量铅的含量测定.

  16. Evaluation of Bi as internal standard to minimize matrix effects on the direct determination of Pb in vinegar by graphite furnace atomic absorption spectrometry using Ru permanent modifier with co-injection of Pd/Mg(NO 3) 2

    de Oliveira, Silvana Ruella; Neto, José Anchieta Gomes

    2007-09-01

    Bismuth was evaluated as an internal standard for the direct determination of Pb in vinegar by graphite furnace atomic absorption spectrometry using Ru as a permanent modifier with co-injection of Pd/Mg(NO 3) 2. The correlation coefficient of the graph plotted from the normalized absorbance signals of Bi versus Pb was r = 0.989. Matrix effects were evaluated by analyzing the slope ratios between the analytical curve obtained from reference solutions prepared in 0.2% (v/v) HNO 3 and analytical curves obtained from Pb additions in red and white wine vinegar samples. The calculated ratios were around 1.04 and 1.02 for analytical curves established applying an internal standard and 1.3 and 1.5 for analytical curves without. Analytical curves in the 2.5-15 μg L - 1 Pb concentration interval were established using the ratio Pb absorbance to Bi absorbance versus analyte concentration, and typical linear correlations of r = 0.999 were obtained. The proposed method was applied for direct determination of Pb in 18 commercial vinegar samples and the Pb concentration varied from 2.6 to 31 μg L - 1 . Results were in agreement at a 95% confidence level (paired t-test) with those obtained for digested samples. Recoveries of Pb added to vinegars varied from 96 to 108% with and from 72 to 86% without an internal standard. Two water standard reference materials diluted in vinegar sample were also analyzed and results were in agreement with certified values at a 95% confidence level. The characteristic mass was 40 pg Pb and the useful lifetime of the tube was around 1600 firings. The limit of detection was 0.3 μg L - 1 and the relative standard deviation was ≤ 3.8% and ≤ 8.3% ( n = 12) for a sample containing 10 μg L - 1 Pb with and without internal standard, respectively.

  17. 微波消解石墨炉原子吸收光谱法测定茶叶中镍%Determination of Nickel in Tea by Graphite Furnace Atomic Absorption Spectrometry with Microwave Digestion

    郑国庚; 李美

    2011-01-01

    [目的]利用微波消解石墨炉原子吸收法测定茶叶中镍含量.[方法]分别从消解液和样品消解量方面进行消解条件的优化,以建立最适合的消解方法.[结果]茶叶样品以5 ml HNO3-2 ml H2O2 混合体系为消解液,坡度升温方式微波高压密闭消解结合石墨炉原子吸收光谱法测定,样品检出限为0.15 μg/g,回收率为97.8%,RSD为1.9%.[结论]该方法简单快速,效率高,劳动强度低,是进行茶叶中镍元素测定的高效方法.%[ Objective ] The study aimed to determine the nickel in tea by using the graphite furnace atomic absorption spectrometry (GFAAS) with microwave digestion. [ Method ] The digestion conditions were optimized separately from the digestion fluid and sample digestion quantity to establish the most appropriate digestion method. [ Result] When 5 ml HNO3 -2 ml H2O2 mixed system was taken as the digestion liquid for digesting the tea samples and the GFAAS combined with the microwave high-pressure airtight digestion under slope heating was used to determine the nickel in the tea samples, the sample detecting limit was 0. 15 μg/g, the recovery was 97.8% and the precise RSD was 1.9%.[ Conclusion ] This method was simple and rapid and had high efficiency and low labor strength, which was a efficient method for detemining nickel element in the tea.

  18. 石墨炉原子吸收光谱法测定醋纤丝束中的砷和铅%Determination of As and Pb in Cellulose Acetate Tow by Graphite Furnace Atomic Absorption Spectrometry

    李文璟; 张修华; 张胜华; 沈军; 曾强; 王惠; 梁琴

    2011-01-01

    采用HNO3-H2O2消化体系,应用石墨炉原子吸收光谱法对10种醋酸纤维丝束(醋纤丝束)中砷和铅的含量进行了测定.结果表明,该方法测定醋纤丝束中的砷、铅具有良好的线性关系,相关系数分别为0.9991、0.9989,砷、铅的定量检出限分别为0.450μg·L-1、0.799 μg·L-1,回收率分别为86.8%~99.6%、92.0%~103.8%.该方法简便、快速、准确度高、重复性好,可用于醋纤丝束中砷、铅的批量测定.%The content of As and Pb in 10 kinds of cellulose acetate tow were determined with graphite furnace atomic absorption spectrometry(GF-AAS) after digested with HNO3 and H2 O2. The results indicated that the method took on good linear relationships. For As and Pb, the correlation coefficients, the detection limit,the recoveries were 0. 9991 and 0. 9989, 0. 450 μg · L-1 and 0. 799 μg · L-1 ,86.8% ~99. 6% and 92.0% ~103.8%, respectively. The proposed method was simple, fast and accurate, which could be applied to determine As and Pb in cellulose acetate tow in bulks.

  19. 火焰原子吸收光谱法测定氢甲酰化反应液中铁%Determination of Iron in Hydroformylation Reaction Liquid by Flame Atomic Absorption Spectrometry

    杜进祥; 王金春; 陈毅芳; 冯辉煌; 郑欣; 陈昌惠

    2001-01-01

    利用冰醋酸作溶剂,采用火焰原子吸收光谱法直接测定氢甲酰化反应液中的总铁含量。以1mol/L盐酸萃取样品,有机相与无机相分别用冰醋酸稀释后用火焰原子吸收法测定,可分别得到样品中有机铁与无机铁的含量。方法简便、快速、可靠,具有较好的精密度和准确度。回收率为93.5%—109%,相对标准偏差为1.0%—2.7%,方法的特征浓度为0.585μg/mL/1%。%Using acetic acid as the solvent, the total iron concentration in hydroformylation reaction liquid was directly determined by flame atomic absorption spectrometry. By 1mol/L HCl as extraction agent and acetic acid as solvent, organic and inorganic iron were quantitatively separated from hydroformylation reaction liquid and determined by FAAS. The method was proved to be simple, rapid, precise and convenient . The recovery is from 93.5% to 109%.The relative standard deviation (RSD)is in the range of 1.0%—2.7%. The characteristic concentration of the method is 0.585μg/mL/ 1%.

  20. Mineral Analysis the Infusion of Black Tea Samples by Atomic Absorption Spectrometry

    Lahiji N.; Tadayon F.; Tamiji F.; Lahiji A. H.

    2013-01-01

    Tea infusion is one of the most popular drinks around the world. Since tea infusion is known to contain several essential nutrients, it is considered a healthy beverage. In this study eight different Iranian brands of tea infusion and eleven brands imported tea infusion samples from another country for Cu, Zn, Mn and Al were determined by flame atomic absorption spectrometry after wet digestion. The results of analysis showed that the extraction rates of minerals from dry black tea to infusio...

  1. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of arsenic and selenium in water and sediment by graphite furnace atomic absorption spectrometry

    Jones, Sandra R.; Garbarino, John R.

    1999-01-01

    Graphite furnace-atomic absorption spectrometry (GF-AAS) is a sensitive, precise, and accurate technique that can be used to determine arsenic and selenium in samples of water and sediment. The GF-AAS method has been developed to replace the hydride generation-atomic absorption spectrometry (HG-AAS) methods because the method detection limits are similar, bias and variability are comparable, and interferences are minimal. Advantages of the GF-AAS method include shorter sample preparation time, increased sample throughput from simultaneous multielement analysis, reduced amount of chemical waste, reduced sample volume requirements, increased linear concentration range, and the use of a more accurate digestion procedure. The linear concentration range for arsenic and selenium is 1 to 50 micrograms per liter in solution; the current method detection limit for arsenic in solution is 0.9 microgram per liter; the method detection limit for selenium in solution is 1 microgram per liter. This report describes results that were obtained using stop-flow and low-flow conditions during atomization. The bias and variability of the simultaneous determination of arsenic and selenium by GF-AAS under both conditions are supported with results from standard reference materials--water and sediment, real water samples, and spike recovery measurements. Arsenic and selenium results for all Standard Reference Water Samples analyzed were within one standard deviation of the most probable values. Long-term spike recoveries at 6.25, 25.0, 37.5 micrograms per liter in reagent-, ground-, and surface-water samples for arsenic averaged 103 plus or minus 2 percent using low-flow conditions and 104 plus or minus 4 percent using stop-flow conditions. Corresponding recoveries for selenium were 98 plus or minus 13 percent using low-flow conditions and 87 plus or minus 24 percent using stop-flow conditions. Spike recoveries at 25 micrograms per liter in 120 water samples ranged from 97 to 99 percent

  2. Analytical control of wollastonite for biomedical applications by use of atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry.

    De Aza, P N; Guitián, F; De Aza, S; Valle, F J

    1998-04-01

    Preliminary in vitro experiments revealed that wollastonite (CaSiO3) is a potentially highly bioactive material that forms a hyroxyapatite (HA) surface layer on exposure to simulated body fluid with an ion concentration, pH and temperature virtually identical with those of human blood plasma. The formation of the HA layer is an essential requirement for an artificial material to be used as bioactive bone substitute. This finding opens up a wide field for biomedical applications of wollastonite. Biomaterials used as implants in the human body require strict control of trace elements and of the toxic species specified in American Society for Testing and Materials F-1185-88 (As, Cd, Hg and Pb) in ceramic hydroxyapatite for surgical implantation. In this work, two types of pseudowollastonite, the high temperature form of wollastonite, were analysed by using cold vapour atomic absorption spectrometry and hydride generation atomic absorption spectrometry, in order to determine the elements stated in the above-mentioned norm, and inductively coupled plasma atomic emission spectrometry to establish the SiO2/CaO ratio of the two materials and analyse for all other impurities introduced by the raw materials and by the processes of synthesis, sintering and grinding. Barium and Mg were especially prominent in raw materials, and Zr, Y, Mg, W, Co and Ni come mainly from the processing. PMID:9684401

  3. Determination of palladium, platinum and rhodium in used automobile catalysts and active pharmaceutical ingredients using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis

    Resano, Martín, E-mail: mresano@unizar.es [Department of Analytical Chemistry, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Flórez, María del Rosario [Department of Analytical Chemistry, Aragón Institute of Engineering Research (I3A), University of Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza (Spain); Queralt, Ignasi [Institute of Earth Sciences Jaume Almera ICTJA-CSIC, Sole Sabarís s/n, 08028 Barcelona (Spain); Marguí, Eva [Department of Chemistry, Faculty of Sciences, Universitat de Girona, Campus Montilivi s/n, 17071 Girona (Spain)

    2015-03-01

    This work investigates the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for the direct determination of Pd, Pt and Rh in two samples of very different nature. While analysis of active pharmaceutical ingredients is straightforward and it is feasible to minimize matrix effects, to the point that calibration can be carried out against aqueous standard solutions, the analysis of used automobile catalysts is more challenging requiring the addition of a chemical modifier (NH{sub 4}F·HF) to help in releasing the analytes, a more vigorous temperature program and the use of a solid standard (CRM ERM®-EB504) for calibration. However, in both cases it was possible to obtain accurate results and precision values typically better than 10% RSD in a fast and simple way, while only two determinations are needed for the three analytes, since Pt and Rh can be simultaneously monitored in both types of samples. Overall, the methods proposed seem suited for the determination of these analytes in such types of samples, offering a greener and faster alternative that circumvents the traditional problems associated with sample digestion, requiring a small amount of sample only (0.05 mg per replicate for catalysts, and a few milligrams for the pharmaceuticals) and providing sufficient sensitivity to easily comply with regulations. The LODs achieved were 6.5 μg g{sup −1} (Pd), 8.3 μg g{sup −1} (Pt) and 9.3 μg g{sup −1} (Rh) for catalysts, which decreased to 0.08 μg g{sup −1} (Pd), 0.15 μg g{sup −1} (Pt) and 0.10 μg g{sup −1} (Rh) for pharmaceuticals. - Highlights: • Solid sampling HR CS GFAAS permits the fast and direct determination of Pd, Pt and Rh. • 2 determinations suffice for the 3 elements (2 of them can be measured simultaneously). • Samples as different as car catalysts and pharmaceuticals can be accurately analyzed. • Aqueous standards (pharmaceuticals) or a solid CRM (catalysts) is used for calibration.

  4. Determination of palladium, platinum and rhodium in used automobile catalysts and active pharmaceutical ingredients using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sample analysis

    This work investigates the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for the direct determination of Pd, Pt and Rh in two samples of very different nature. While analysis of active pharmaceutical ingredients is straightforward and it is feasible to minimize matrix effects, to the point that calibration can be carried out against aqueous standard solutions, the analysis of used automobile catalysts is more challenging requiring the addition of a chemical modifier (NH4F·HF) to help in releasing the analytes, a more vigorous temperature program and the use of a solid standard (CRM ERM®-EB504) for calibration. However, in both cases it was possible to obtain accurate results and precision values typically better than 10% RSD in a fast and simple way, while only two determinations are needed for the three analytes, since Pt and Rh can be simultaneously monitored in both types of samples. Overall, the methods proposed seem suited for the determination of these analytes in such types of samples, offering a greener and faster alternative that circumvents the traditional problems associated with sample digestion, requiring a small amount of sample only (0.05 mg per replicate for catalysts, and a few milligrams for the pharmaceuticals) and providing sufficient sensitivity to easily comply with regulations. The LODs achieved were 6.5 μg g−1 (Pd), 8.3 μg g−1 (Pt) and 9.3 μg g−1 (Rh) for catalysts, which decreased to 0.08 μg g−1 (Pd), 0.15 μg g−1 (Pt) and 0.10 μg g−1 (Rh) for pharmaceuticals. - Highlights: • Solid sampling HR CS GFAAS permits the fast and direct determination of Pd, Pt and Rh. • 2 determinations suffice for the 3 elements (2 of them can be measured simultaneously). • Samples as different as car catalysts and pharmaceuticals can be accurately analyzed. • Aqueous standards (pharmaceuticals) or a solid CRM (catalysts) is used for calibration. • 6–9 μg g−1 (catalysts) and 0.1–0

  5. Ten element contents and their distribution in fruits determinated by atomic absorption spectrometry%原子吸收光谱法测定水果中10种元素含量及分布

    蔡艳荣; 刘媛; 李玲玲; 王伟

    2011-01-01

    Objective To investigate the contents and distributions of the Zn, Cu, K, Ca, Mg, Mn, Pb, Cd, Cr and Se elements in the fruits. Methods The fruit samples were digested with wet method. Contents of zinc, copper,calcium,magnesium,potassium and manganese were determined by flame atomic absorption spectrometry (FAAS).Contents of lead, cadmium, chromium and selenium were determined by graphite furnace atomic absorption spectrometry( GFAAS). Results There existed differences for the element distribution in each part of the fruits. The contents of lead in the grapes, dried jujubes and papaya were close to the pollutant concentration limits, but their contents were lower than standard limits. The contents of chromium in the Guoguang apples, pears, dry jujubes and cherry tomatoes were higher than standard limits. Selenium was detected in the Guoguang apples, bananas, pears, dry jujubes, papaya and pomelo. The contents of copper in the grapes and dry jujubes exceeded standard limits. The contents of zinc were lower than standard limits. The calcium contents were the highest in the papaya. The contents of magnesium and manganese were the highest in the dry jujubes. The contents of potassium were higher in the dry jujubes,pomelo and cherry tomato. Conclusion The highest levels of the elements were in the seeds, and the second levels were in the skin ,the lowest levels were in the pulp. The element contents of the peel were higher than those the pulp.%目的 调查水果中锌、铜、钾、钙、镁、锰、铅、镉、铬和硒10种元素含量分布情况.方法 采用湿法消解水果样品,火焰原子吸收光谱法检测水果中的锌、铜、钾、钙、镁和锰的含量,石墨炉原子吸收光谱法检测铅、镉、铬和硒的含量.结果 10种元素在水果中各部位的分布有比较大的差异.葡萄、干枣和木瓜中铅含量接近于污染物浓度限量,但没有超过标准.国光苹果、梨、干枣和圣女果中铬的含量都超标.国光苹

  6. Determination of chromium content in potato by graphite furnace atomic absorption spectrometry%石墨炉原子吸收光谱法测定马铃薯中铬含量

    向文军; 陈安银

    2014-01-01

    采用石墨炉原子吸收光谱法测定马铃薯中铬含量,采用了一种新的前处理方法(硝酸+硫酸+过氧化氢)的湿法消解法,并与传统湿法消解法(硝酸+高氯酸)作对比。结果表明,新的湿法消解法测得铬的含量略高于传统消解法测得铬的含量,加标回收率在92.7%~99.2%,精密度RSD为1.7135%,都优于传统的湿法消解法,避免了危险性较大的高氯酸,且反应温和,操作安全,简单,消解完全,结果准确,可以作为选择方法在实际工作中应用推广。%Graphite furnace atomic absorption spectrometry was used to determine content of chromium, and a comparison was made between a new wet digestion( nitric acid,hydrogen peroxide and sulfuric acid)and traditional wet digestion( nitric acid and perchloric acid)for pretreatment. The results showed that the content of Cr measured with new wet digestion method is slightly higher than that of traditional di-gestion method measured chromium,the recovery rate was 92. 7% ~99. 2% and RSD of precision was 1. 713 5%,the new wet digestion method is better than the traditional,the larger risk of perchloric acid was avoided,and the mild reaction conditions,safe operation,simple,complete digestion,accurate,and can be used as a selection method was applied in practical work.

  7. Development of a sequential injection dispersive liquid-liquid microextraction system for electrothermal atomic absorption spectrometry by using a hydrophobic sorbent material: Determination of lead and cadmium in natural waters

    A novel on-line sequential injection (SI) dispersive liquid-liquid microextraction (DLLME) system coupled to electrothermal atomic absorption spectrometry (ETAAS) was developed for metal preconcentration in micro-scale, eliminating the laborious and time consuming procedure of phase separation with centrifugation. The potentials of the system were demonstrated for trace lead and cadmium determination in water samples. An appropriate disperser solution which contains the extraction solvent (xylene) and the chelating agent (ammonium pyrrolidine dithiocarbamate) in methanol is mixed on-line with the sample solution (aqueous phase), resulting thus, a cloudy solution, which is consisted of fine droplets of xylene, dispersed throughout the aqueous phase. Three procedures are taking place simultaneously: cloudy solution creation, analyte complex formation and extraction from aqueous phase into the fine droplets of xylene. Subsequently the droplets were retained on the hydrophobic surface of PTFE-turnings into the column. A part of 30 μL of the eluent (methyl isobutyl ketone) was injected into furnace graphite for analyte atomization and quantification. The sampling frequency was 10 h-1, and the obtained enrichment factor was 80 for lead and 34 for cadmium. The detection limit was 10 ng L-1 and 2 ng L-1, while the precision expressed as relative standard deviation (RSD) was 3.8% (at 0.5 μg L-1) and 4.1% (at 0.03 μg L-1) for lead and cadmium respectively. The proposed method was evaluated by analyzing certified reference materials and was applied to the analysis of natural waters.

  8. Separation and preconcentration of platinum-group metals from spent autocatalysts solutions using a hetero-polymeric S, N-containing sorbent and determination by high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Eskina, Vasilina V; Dalnova, Olga A; Filatova, Daria G; Baranovskaya, Vasilisa B; Karpov, Yuri A

    2016-10-01

    This paper describes the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for determination of Pt, Pd and Rh after separation and concentration by original in-house developed heterochain polymer S, N-containing sorbent. The methods of sample preparation of spent ceramic-based autocatalysts were considered, two of which were used: autoclave decomposition in mixture of acids HCl:HNO3 (3:1) and high-temperature melting with K2S2O7. Both methods anyway limit the direct determination of analytes by HR CS GFAAS. Using the first method it is an incomplete digestion of spent autocatalysts samples, since the precipitate is Si, and the rhodium metal dissolves with difficulty and partially passes into solution. In contrast to the first method, the second method allow to completely transfer analytes into solution, however, the background signal produced by the chemical composition of the flux, overlaps the analytical zone. It was found, that Pt, Pd and Rh contained in the spent ceramic automotive catalysts could be effectively separated and concentrated by heterochain polymer S, N-containing sorbent, which has high sorption capacity, selectivity and resistant to dilute acids. The chosen HR CS GFAAS analysis conditions enable us to determine Pt, Pd and Rh with good metrological characteristics. The concentrations of Pt, Pd and Rh in two samples of automobile exhaust catalysts were found in range of 0.00015-0.00050; 0.170-0.189; 0.0180-0.0210wt%, respectively. The relative standard deviation obtained by HR CS GFAAS was not more than 5%. Limits of detection by HR CS GFAAS achieved were 6.2·10(-6)wt% for Pt, 1.8·10(-6)wt% for Pd, and 3.4·10(-6)wt% for Rh. Limits of determination achieved by HR CS GFAAS were 1.1·10(-5)wt% for Pt, 6.9·10(-5)wt% for Pd, and 8.3·10(-5)wt% for Rh. To control the accuracy of PGM in sorption concentrates by HR CS GFAAS method, it was appropriate to conduct an inter-method comparative experiment. The

  9. Determination of Trace Amount of Cadmium by Atomic Absorption Spectrometry in Table Salt after Solid Phase Preconcentration Using Octadecyl Silica Membrane Disk Modified by a New Derivative of Pyridine

    Mahmood Payehghadr; Sousan Esmaeilpour; Mohammad Kazem Rofouei; Laleh Adlnasab

    2013-01-01

    Silica-C18 bonded disk modified by a four-dentate Schiff base has been used for preconcentration of cadmium in table salt samples followed by flame atomic absorption spectrometry. The method is based on the adsorption of Cd on 1,2-bis(pyridin-2-ylmethylene) hydrazine as Schiff base ligand on silica-C18 disk. The effects of several factors such as type and concentration of the eluent, pH of sample solution, amount of ligand, and breakthrough volume have been optimized based on one variable at ...

  10. Speciation of organometallic compounds by Zeeman atomic absorption spectrometry with liquid chromatography

    A method for the determination of organometallic compounds in the ppB range includes separation of the desired species with a high pressure liquid chromatograph and determination of the trace element by Zeeman atomic absorption spectrometry. The analysis of a mixture of vitamin B12 and Co(NO3)2 is described as a demonstration of the method. Determination of many enzymes and coenzymes having a metal ion in their functional center and of many toxic metals in environmental samples are other fields for application of this method

  11. 火焰原子吸收光谱法测定高炉尘中铟%Determination of trace indium in blast furnace dust by flame atomic absorption spectrometry

    吕佳; 王光明; 李辽沙

    2011-01-01

    After the sample was dissolved with mixed acid, excessive sodium hydroxide was added to dissolve indium hydroxide for separation and enrichment of trace indium in blast furnace dust. Then, the content of indium in sample was determined by flame atomic absorption spectrometry. Consequently, a simple determination method of trace indium in complex system was established. The influence factors on the dissolution and determination results were investigated including the dosages of acid, various alkaline liquors and the dosage of alkali. Moreover, the interference of coexisting ions was studied. Finally, the optimal experimental conditions were obtained. The results showed that sodium hydroxide could effectively dissolve trace indium hydroxide. Meanwhile, the ions of iron and magnesium were precipitated, removing most interference elements in blast furnace dust. The relative standard deviation (RSD) of this method was less than 4. 2 %, and the recoveries were 98 %-103 %.%采用混合酸溶样,过量氢氧化钠溶解氢氧化铟分离富集高炉尘中痕量铟,火焰原子吸收光谱法测定样品中铟含量,建立了一种测定复杂体系中痕量铟的简便方法.对实验过程中的酸用量、不同碱液及碱用量对溶解及测定结果的影响、共存离子的干扰等情况进行了考察,确定了最佳实验条件.实验结果表明,氢氧化钠能够有效的溶解痕量氢氧化铟,同时沉淀了铁、镁等离子,去除了高炉尘中大部分的干扰元素.方法相对标准偏差小于4.2%,回收率在98%~103%之间.

  12. Determinação direta de crômio em açúcar e leite por espectrometria de absorção atômica com atomização eletrotérmica em forno de grafite Direct determination of chromium in sugar and milk using graphite furnace atomic absorption spectrometry

    Sueli P. Quináia; Joaquim A. Nóbrega

    2000-01-01

    A fast and direct method for the determination of Cr in milk and cane sugar suspensions using graphite furnace atomic absorption spectrometry with Zeeman-effect background correction is described. No sample pre-treatment was necessary, minimizing the risk of contamination. The concentration of chromium in cane sugar was evaluated using Cr reference solutions prepared in 1% v/v HNO3 solution. The milk samples were introduced into the furnace with a mixture of amines for avoiding the autosample...

  13. Accelerator mass spectrometry analysis of aroma compound absorption in plastic packaging materials

    Stenström, Kristina; Erlandsson, Bengt; Hellborg, Ragnar; Wiebert, Anders; Skog, Göran; Nielsen, Tim

    1994-05-01

    Absorption of aroma compounds in plastic packaging materials may affect the taste of the packaged food and it may also change the quality of the packaging material. A method to determine the aroma compound absorption in polymers by accelerator mass spectrometry (AMS) is being developed at the Lund Pelletron AMS facility. The high sensitivity of the AMS method makes it possible to study these phenomena under realistic conditions. As a first test low density polyethylene exposed to 14C-doped ethyl acetate is examined. After converting the polymer samples with the absorbed aroma compounds to graphite, the {14C }/{13C } ratio of the samples is measured by the AMS system and the degree of aroma compound absorption is established. The results are compared with those obtained by supercritical fluid extraction coupled to gas chromatography (SFE-GC).

  14. 碳纳米管富集-火焰原子吸收法测定饮用水中的微量镉%Determination of cadmium in drinking water by carbon nanotubes enrichment combined with flame atomic absorption spectrometry

    李立; 雷超; 王芳权; 申屠超

    2011-01-01

    Cadmium in drinking water was enriched by adsorption column packed with nitric acid active carbon nanotubes and the content of cadmium in eluent was measured by flame atomic absorption spectrometry.Experimental conditions related to the adsorption ability of carbon nanotubes and the elution of cadmium was optimized and the optimal conditions for the enrichment of cadmium in drinking water with carbon nanotubes were finally established. Experimental results indicated that carbon nanotubes active by 0.50mol/L HNO3 could adsorb quantitatively cadmium in drinking water and the adsorbed cadmium could be totally eluted by 0.50mol/L HNO3.Spiked recoveries of this method ranged from 102.1% to 106.4% demonstrated the accuracy and reliability of the test results. The proposed method could be applied to determine trace cadmium in real water samples.%采用硝酸活化后的碳纳米管吸附柱来富集饮用水中的镉,用火焰原子吸收光谱法测定洗脱液中的镉.对碳纳米管吸附与洗脱镉的有关实验条件进行了详细的研究与优化,确定了碳纳米管富集饮用水中镉的最佳条件.实验结果表明,用0.50moL/L HNO3活化的碳纳米管吸附柱能定量吸附饮用水中的镉,并用0.50m01/L HNO3能完全洗脱碳纳米管所吸附的镉.本法的加标回收率为102.1%~106.4%,结果准确可靠,可应用于实际水样中微量镉的测定.

  15. Development of an automated sequential injection on-line solvent extraction-back extraction procedure as demonstrated for the determination of cadmium with detection by electrothermal atomic absorption spectrometry

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection (SI) on-line solvent extraction-back extraction separation/preconcentration procedure is described. Demonstrated for the assay of cadmium by electrothermal atomic absorption spectrometry (ETAAS), the analyte is initially complexed with ammonium...... pyrrolidinedithiocarbamate (APDC) in citrate buffer and the chelate is extracted into isobutyl methyl ketone (IBMK), which is separated from the aqueous phase by means of a newly designed dual-conical gravitational phase separator. A metered amount of the organic eluate is aspirated and stored in the PTFE holding coil (HC......) of the SI-system. Afterwards, it is dispensed and mixed with an aqueous back extractant of dilute nitric acid containing Hg(II) ions as stripping agent, thereby facilitating a rapid metal-exchange reaction with the APDC ligand and transfer of the Cd into the aqueous phase. The aqueous phase is...

  16. SPECIATION OF SELENIUM(IV) AND SELENIUM(VI) USING COUPLED ION CHROMATOGRAPHY: HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY

    A simple method was developed to speciate inorganic selenium in the microgram per liter range using coupled ion chromatography-hydride generation atomic absorption spectrometry. Because of the differences in toxicity and adsorption behavior, determination of the redox states selenite, Se(IV), and s...

  17. Flame atomic absorption determination of ultra trace zinc after preconcentration

    Complete text of publication follows. The determination of toxic metal ions is becoming increasingly important because of the increased interest in environmental samples including water, soil, plant, etc. Although flame atomic absorption spectrometry is widely used because of its low cost, its sensitivity is usually insufficient for the low concentrations found in environmental samples. Matrix interferences are another problem in atomic absorption spectrometric determinations of trace elements. Solving these problems requires a preconcentration and a matrix elimination step (A. Uzun et al., Talanta, 54, (2001)197). Zinc is a biologically essential micronutrient, and coordinates with macromolecules as a cofactor to confer catalytic function of structural integrity. Such metalloproteins have been implicated in diverse functions ranging from protein, nucleic acid, carbohydrate, and lipid metabolism, to gene transcription (B.L. Vallee et al., Physio. Revs, 73:1 (1993) 99). Zinc is frequently present at trace level in cadmium and their compounds. Numerous methods have been published for such determination. However, they are not simple and usually require extensive and laborious steps for separation of zinc from cadmium (C.W. McDonald et al., Anal. Chem., 46 (1974) 300). In this work a simple, reliable and rapid method for determination of ultra trace zinc by flame atomic absorption spectrometry is presented. The limit of detection (LOD), of the proposed method for the determination of Zn2+ ion was studied under the optimal experimental conditions. The LOD obtained from CLOD=KbSbm-1 (J.D. Ingle et al., Spectrochemical Analysis, Prentice Hall, Englewood Cliffs, NJ, 1988) for a numerical factor Kb=3 is 120 ng.L-1.The method was successfully applied for the determination of zinc ion in different samples, especially determination of ultra trace amount of zinc in waters and plants.

  18. Determination of trace metallic elements in Huidouba by flame atomic absorption spectrometry%火焰原子吸收法测定灰兜巴中微量金属元素

    杨孝容; 王延云; 向清祥; 熊俊如

    2013-01-01

    The correlation of trace metallic elements in Huidouba and cure diabetes mellitus was established according to results of determination of metal elements in Huidouba by flame atomic absorption spectrometry (FAAS).Huidouba,old tea and dirt of con-necting Huidouba were collected as samples .The samples were extracted with water through boiling and was filtered with gauze ,then the supernatant liquid was digested by nitric acid and perchloric acid and was dissolved in dilute nitric acid and was centrifugated , the centrifugate was used as analytical solution for FAAS .Zinc(Zn),chromium(Cr),selenium(Se),magnesium(Mg),manganese (Mn),cobalt(Co),copper(Cu),nickel(Ni),cadmium(Cd)were determined by FAAS.The results showed that the contents of Cu,Ni,Cd were low in the Huidouba ,however,their values in blood and hair of diabetic patients were higher as compared to nondia -betic patients.In contrast,Zn,Cr,Se,Mg,Mn,Co were high in Huidouba ,their contents in blood and hair of diabetic patients were lower than nondiabetic patients ’s.The levels of essential trace metallic elements ,Zn,Cr,Se,Mg,Mn,Co,Cu,Ni,Cd in Huidouba samples are very beneficial to diabetes mellitus .Huidouba may play a major role in allaying or curing diabetes mellitus .%用火焰原子吸收法测定灰兜巴中微量金属元素的含量,探讨灰兜巴中微量金属元素与治疗糖尿病的相关性。采集灰兜巴以及灰兜巴连接的老茶叶和土壤试样,水煮提取、纱布过滤、静止后取其上层液,用HNO3-HClO4消解,再用稀HNO3溶解,定容,离心,取其上清液,用火焰原子吸收光谱法测定Zn、Cr、Se、Mg、Mn、Co、Cu、Ni和Cd 9种元素的含量。结果表明糖尿病人常偏高的Cu、Ni和Cd元素在灰兜巴中含量相对较低,而糖尿病人常偏低的Zn、Cr、Se、Mg、Mn和Co元素在灰兜巴中的含量相对较高。灰兜巴中Zn、Cr、Se、Mg、Mn、Co、Cu、Ni和Cd等重要微量金属元素的含量很适合糖尿病人,

  19. FAAS法测定打瓜不同部位微量元素的含量%Determination of microelement in different parts of watermelon by flame atomic absorption spectrometry

    姜波; 胡文忠; 姜爱丽; 田密霞; 马堃; 董珊

    2012-01-01

    Microwave and ultrasonic wave techniques were used for disposing watermelon samples. The contents of Ca,Cu,Zn, Fe, K, Mn, Mg and Na in different parts of watermelon were determined by flame atomic absorption spectrometry. The recoveries for each element were within the range of 95% to 105% ,the average recoveries were 96.2% to 104.0%,and RSD of the method for 10 times determinations were 0.23% to 2.98%,the method was accuracy and precise. The results showed that the contents of potassium ,calcium and magnesium were high in rind,endodermis,pulp and dried seed. The order of the content of Ca was rind〉seed〉endodermis〉 pulp, Cu was seed 〉rind 〉endodermis 〉pulp,Zn was seed 〉rind 〉pulp i〉 endodermis, Fe was seed 〉rind 〉pulp 〉 endodermis, K was seed 〉endodermis 〉rind 〉pulp, Mn was seed 〉rind 〉pulp 〉endodermis, Mg was seed 〉rind 〉 endodermis 〉pulp,Na was seed 〉rind 〉endodermis 〉pulp. The results of watermelon could provide theoretical basis for developing and utilizing the melon.%采用微波消解和超声波技术处理打瓜样品,空气-乙炔火焰原子吸收光谱法测定打瓜不同部位中的钙、铜、锌、铁、钾、锰、镁和钠含量。此方法的各元素加标回收率均在95%~105%之间,平均回收率在96.2%~104.0%之间,10次测定的相对标准偏差为0.23%~2.98%,准确性好、精密度高。研究结果表明,在新鲜的打瓜外皮、内皮、瓤和干燥的瓜籽中,钾、钙和镁含量较高,其中Ca含量顺序为外皮〉籽〉内皮〉瓤,Cu含量为籽〉外皮〉内皮〉瓤,Zn含量为籽〉外皮〉瓤≥内皮,Fe含量为籽〉外皮〉瓤〉内皮,K含量为籽〉内皮〉外皮〉瓤,Mn含量为籽〉外皮〉瓤〉内皮,Mg含量为籽〉外皮〉内皮〉瓤,Na含量为籽〉外皮〉内皮〉瓤,研究结果可为打瓜瓤、外皮和内皮的开发利用提供理论依据。

  20. Continuous Determination of 12 Elements in Geochemical Samples by Inductively Coupled Plasma-Atomic Emission Spectrometry and Flame Atomic Absorption Spectrometry%电感耦合等离子体发射光谱法和火焰原子吸收光谱法连续测定化探样品中12个元素

    于阗; 张连起; 陈小迪

    2011-01-01

    The continuous determination of 12 elements in geochemical samples by inductive coupled plasma-atomic emission spectrometry (ICP-AES) and flame atomic absorption spectrometry ( FAAS) was reported in this paper. Samples were digested with mixed acid of HCI-HF-HNO3-HC1O4 and Cu, Pb, Zn, Co, Ni, Cr, Sr, Ba, V, Mn in the sample solution were determined directly by ICP-AES. Then, Ag and Cd in the same sample solution were enriched by extraction with potassium iodide-methyl isobutyl ketone ( KI-MIBK) and determined by FAAS. The precision of FAAS method for Ag and Cd was 6. 5% and 4. 7% RSD ( n = 12) , respectively. In comparison with the common analytical method, the proposed method provides the higher sensitivity, good accuracy and precision, high economy, high efficiency and is suitable for routine analysis of these elements in geochemical samples.%建立了地质化探样品中不同含量和检出限要求的12个元素的连续测定方法.样品经一次取样,用盐酸-氢氟酸-硝酸-高氯酸溶样,电感耦合等离子体发射光谱法测定铜、铅、锌、钴、镍、镉、锶、钡、钒、锰后,加碘化钾-甲基异丁基甲酮萃取分离,火焰原子吸收光谱法测定银、镉.银、镉的相对标准偏差(RSD,n=12)分别为6.5%、4.7%.与现行分析方法相比,建立的方法灵敏度和精密度高、准确度好,降低了生产成本,缩短了检测时间,尤其适合大量化探样品的测定.

  1. Laser mass spectrometry for selective ultratrace determination

    Wendt, K; Müller, P; Nörtershäuser, W; Schmitt, A; Trautmann, N; Bushaw, B A

    1999-01-01

    Resonance ionization mass spectrometry has been explored in respect to its capabilities for isobaric suppression, isotopic selectivity, and overall efficiency. Theoretical calculations within the density matrix formalism on coherent multi-step excitation processes predict high specifications, which have been confirmed by spectroscopic measurements in Ca and which make the technique attractive for ultratrace detection. Analytical applications are found in the determination of the ultratrace isotope sup 4 sup 1 Ca for cosmochemical, radiodating, and medical applications.

  2. Mercury in Environmental and Biological Samples Using Online Combustion with Sequential Atomic Absorption and Fluorescence Measurements: A Direct Comparison of Two Fundamental Techniques in Spectrometry

    Cizdziel, James V.

    2011-01-01

    In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

  3. Determination of boron in waters and in water extracts from wastes by molecular and atomic absorption spectrometry following preliminary boron separation by extraction of its complex with 2-ethylhexane-1,3-diol

    Two methods for boron determination were developed and tested. The analysis is based on boron separation and preconcentration by extraction from an acid aqueous solution into a chloroform solution of 2-ethylhexane-1,3-diol followed by reextraction into aqueous sodium hydroxide, and subsequent molecular absorption spectroscopic determination with curcumine at 543 nm or atomic absorption spectroscopic determination at 249.8 nm in a nitrous oxide-acetylene flame. The limits of determination (3s criterion) for the two methods are 0.002 and 0.1 mg/l, respectively. The methods were compared with the conventional procedure based on the use of azomethine-H. While the sensitivities of the methods are comparable (the limit of determination for the azomethine-H method is 0.02 mg/l), the proposed methods exhibit a better reliability and are widely applicable to the determination of total boron in all types of water and water extracts. (author) 3 tabs., 37 refs

  4. New cryogenic trap design for speciation analysis of arsenic by hydride generation-atomic absorption spectrometry

    Svoboda, Milan; Kratzer, Jan; Dědina, Jiří

    Praha, 2014. s. 240-240. ISBN 978-80-905704-1-2. [European Symposium on Atomic Spectrometry ESAS 2014 & Czech-Slovak Spectroscopic Conference /15./. 16.03.2014-21.03.2014, Praha] R&D Projects: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : atomic absorption spectrometry * hydride generation * cryogenic trapping Subject RIV: CB - Analytical Chemistry, Separation

  5. Determination of phytoplankton composition using absorption spectra

    Martínez Guijarro, Mª Remedios; Romero Gil, Inmaculada; Paches Giner, Maria Aguas Vivas; González del Rio Rams, Julio; Martí Insa, Carmen Mª; GIL SEGUÍ, GERMA; Ferrer, Alberto; FERRER, J.

    2009-01-01

    Characterisation of phytoplankton communities in aquatic ecosystems is a costly task in terms of time, material and human resources. The general objective of this paper is not to replace microscopic counts but to complement them, by fine-tuning a technique using absorption spectra measurements that reduces the above-mentioned costs. Therefore, the objective proposed in this paper is to assess the possibility of achieving a qualitative determination of phytoplankton communities by ...

  6. Microwave Digestion--Determination of Lead in Laver by Graphite Furnace Atomic Absorption Spectrometry%微波消解-石墨炉原子吸收光谱法测定紫菜中的铅

    林彬

    2014-01-01

    In order to detect the concentration of laver, graphite furnace atomic absorption spectrometry was used. Microwave digestion technology was applied to pretreat laver, using the HNO3-H2O2 as oxidizing agent, the two ammonium hydrogen phosphate as matrix modifier. This paper investigated the influence of matrix modifier concentration, ashing temperatureand atomization temperature to the light absorption value. Under the best detecting conditions, there was a good linear relationship between the concentration of lead and the absorption value, and the linear equation was A=0.0058C+0.0052, the correlation coefifcient was 0.9994, the detection limit was 1.0μg/L. The RSD of spiked samples was 1.512%-2.469%, under 10 consecutive detecting, and the rate of recovery was 98.4%-101.1%. This method was simple, speedy,has a good reproducibility, and it’s suitable for daily batch testing.%应用石墨炉原子吸收光谱法测定紫菜中铅含量,以HNO3-H2O2为氧化剂,微波消解处理样品,磷酸二氢铵作测铅基体改进剂,考察了基体改进剂浓度、灰化温度、原子化温度对吸光值的影响。在最优条件下,低浓度的铅与吸光值具有良好的线性关系,线性方程为:A=0.0058C+0.0052,r=0.9994,检出限为1.0μg/L。运用该方法测定10次加标样的RSD为1.512%~2.469%,加标回收率为98.4%~101.1%。该方法简单、快速、重现性好,适合日常批量检测。

  7. Spectrometric analysis of process etching solutions of the photovoltaic industry--determination of HNO3, HF, and H2SiF6 using high-resolution continuum source absorption spectrometry of diatomic molecules and atoms.

    Bücker, Stefan; Acker, Jörg

    2012-05-30

    The surface of raw multicrystalline silicon wafers is treated with HF-HNO(3) mixtures in order to remove the saw damage and to obtain a well-like structured surface of low reflectivity, the so-called texture. The industrial production of solar cells requires a consistent level of texturization for tens of thousands of wafers. Therefore, knowing the actual composition of the etch bath is a key element in process control in order to maintain a certain etch rate through replenishment of the consumed acids. The present paper describes a novel approach to quantify nitric acid (HNO(3)), hydrofluoric acid (HF), and hexafluosilicic acid (H(2)SiF(6)) using a high-resolution continuum source graphite furnace absorption spectrometer. The concentrations of Si (via Si atom absorption at the wavelength 251.611 nm, m(0),(Si)=130 pg), of nitrate (via molecular absorption of NO at the wavelength 214.803 nm, [Formula: see text] ), and of total fluoride (via molecular absorption of AlF at the wavelength 227.46 nm, m(0,F)=13 pg) were measured against aqueous standard solutions. The concentrations of H(2)SiF(6) and HNO(3) are directly obtained from the measurements. The HF concentration is calculated from the difference between the total fluoride content, and the amount of fluoride bound as H(2)SiF(6). H(2)SiF(6) and HNO(3) can be determined with a relative uncertainty of less than 5% and recoveries of 97-103% and 96-105%, respectively. With regards to HF, acceptable results in terms of recovery and uncertainty are obtained for HF concentrations that are typical for the photovoltaic industry. The presented procedure has the unique advantage that the concentration of both, acids and metal impurities in etch solutions, can be routinely determined by a single analytical instrument. PMID:22608457

  8. Towards broadening thermospray flame furnace atomic absorption spectrometry: Influence of organic solvents on the analytical signal of magnesium

    Ezequiel Morzan; Jorge Stripeikis; Mabel Tudino

    2015-01-01

    This study demonstrates the influence of the solvent when thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) is employed for the determination of elements of low volatility, taking magnesium (Mg) as leading case. Several organic solvents/water solutions of different characteristics (density, surface tension, viscosity, etc.) and proportions were employed for the TS-FF-AAS analytical determination. To this end, solutions containing methanol, ethanol and isopropanol in water w...

  9. Microwave Digestion of Hair Samples in Closed Vessels for the Determinations of Copper and Iron by Derivative Flame Atomic Absorption Spectrometry using Flow-injection Technique%微波溶样-流动注射-导数火焰原子吸收光谱测定人发中的铜和铁

    陈兰菊; 郑连义; 孙汉文

    2002-01-01

      本文以微波消解人发样,利用流动注射-导数火焰原子吸收法测定其中微量铜、铁的含量。微波溶样技术具有快捷、污染小、损失少、消化完全等优点;流动注射进样技术可以克服常规火焰原子吸收法耗样量大和基体干扰严重的缺点;导数技术应用于火焰原子吸收可提高方法的灵敏度和信号的选择性。微波溶样、流动注射与导数技术相结合应用于火焰原子吸收成功地测定了人发中的微量铜和铁。%  A new method was presented for the determinations of copper and iron in hair samples,which was based on the technique of microwave digestion in closed vessels,flow-injection and derivative flame atomic absorption spectrometry. The technique of microwave digestion is convenient, little of pollution, less in loss, and complete digestion. The flaws that sampling is large and matrix interference is serious in conventional flame atomic absorption spectrometry(FAAS) were overcome by flow-injection sampling technique. The sensitivity and signal selectivity were enhanced when derivative technique was used. This new method that derivative flame atomic absorption spectrometry combined with microwave digestion and flow-injection technique is simple and rapid with satisfactory results for determination of copper and iron in hair.

  10. Near edge X-ray absorption mass spectrometry on coronene

    Reitsma, G.; Deuzeman, M. J.; Hoekstra, R.; Schlathölter, T. [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands); Boschman, L. [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands); Kapteyn Astronomical Institute, University of Groningen, Groningen (Netherlands); Hoekstra, S. [Van Swinderen Institute, University of Groningen, Groningen (Netherlands)

    2015-01-14

    We have investigated the photoionization and photodissociation of free coronene cations C{sub 24}H{sub 12}{sup +} upon soft X-ray photoabsorption in the carbon K-edge region by means of a time-of-flight mass spectrometry approach. Core excitation into an unoccupied molecular orbital (below threshold) and core ionization into the continuum both leave a C 1s vacancy, that is subsequently filled in an Auger-type process. The resulting coronene dications and trications are internally excited and cool down predominantly by means of hydrogen emission. Density functional theory was employed to determine the dissociation energies for subsequent neutral hydrogen loss. A statistical cascade model incorporating these dissociation energies agrees well with the experimentally observed dehydrogenation. For double ionization, i.e., formation of intermediate C{sub 24}H{sub 12}{sup 3+⋆}trications, the experimental data hint at loss of H{sup +} ions. This asymmetric fission channel is associated with hot intermediates, whereas colder intermediates predominantly decay via neutral H loss.

  11. Determination of Trace Cobalt in soil with graphite furnace atomic absorption spectrometry%石墨炉原子吸收光谱法测定土壤中痕量钴

    张建军

    2013-01-01

    The nitric acid hydrofluoric acid hydrochloric acid mixed acid system of microwave digestion soil sample , method of Spectrophotometry for determination of Trace Cobalt in soil with graphite furnace atomic absorption .By the determination results of standard soil samples show that , the method is easy to operate , accurate , and reliable .%建立了硝酸-氢氟酸-盐酸混酸体系微波消解土壤样品,石墨炉原子吸收分光光谱法测定土壤中痕量钴的方法。通过对标准土样的测定结果表明,该方法容易操作、准确、可靠。

  12. Determination of Lead Element in the Jellied Bean Curd with Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry%微波消解-石墨炉原子吸收法测定豆腐花中的铅

    鲁伦文; 谭平; 赵克勤

    2011-01-01

    [目的]建立一种简便、快速测定豆腐花中铅含量的方法.[方法]采用微波消解法处理豆腐花样品,石墨炉原子吸收光谱法测定豆腐花中铅含量,并通过正交试验设计方法对微波消解参数进行了优化.[结果]测定铅的标准曲线相关系数为0.9994,相时标准偏差在0.32%~2.17%,加标回收率在95%~104%,检出限为1.454μg/L.[结论]用微波消解作为预处理手段,以石墨炉原子吸收分光光度法测豆腐花中铅的含量是一种可行的方法,具有精密度高、准确度好等优点.%[ Objective ] This paper aimed to establish a fast and convenient way to determine the contentof lead in the jellied bean curd. [ Methed ] The lead content in jellied bean curd samples was determined by microwave digestion and graphite furnace atomic absorption spectroscopy (GF-AAS). The working conditions of microwave digestion and atomic absorption determination were optimized. [ Result] The correlation coefficient of standard curve was 0.999 4 with relative standard deviation less than 2. 17 percent. The detection limit was 1.454 μg,/L. [Conclusion] It was a simple, precise, fast and feasible way to determine the lead content in jellied bean curd.

  13. Determination of phytoplankton composition using absorption spectra.

    Martínez-Guijarro, R; Romero, I; Pachés, M; Del Río, J G; Martí, C M; Gil, G; Ferrer-Riquelme, A; Ferrer, J

    2009-05-15

    Characterisation of phytoplankton communities in aquatic ecosystems is a costly task in terms of time, material and human resources. The general objective of this paper is not to replace microscopic counts but to complement them, by fine-tuning a technique using absorption spectra measurements that reduces the above-mentioned costs. Therefore, the objective proposed in this paper is to assess the possibility of achieving a qualitative determination of phytoplankton communities by classes, and also a quantitative estimation of the number of phytoplankton cells within each of these classes, using spectrophotometric determination. Samples were taken in three areas of the Spanish Mediterranean coast. These areas correspond to estuary systems that are influenced by both continental waters and Mediterranean Sea waters. 139 Samples were taken in 7-8 stations per area, at different depths in each station. In each sample, the absorption spectrum and the phytoplankton classes (Bacyllariophyceae (diatoms), Cryptophyceae, Clorophyceae, Chrysophyceae, Prasynophyceae, Prymnesophyceae, Euglenophyceae, Cyanophyceae, Dynophyceae and the Synechococcus sp.) were determined. Data were analysed by means of the Partial Least Squares (PLS) multivariate statistical technique. The absorbances obtained between 400 and 750 nm were used as the independent variable and the cell/l of each phytoplankton class was used as the dependent variable, thereby obtaining models which relate the absorbance of the sample extract to the phytoplankton present in it. Good results were obtained for diatoms (Bacillarophyceae), Chlorophyceae and Cryptophyceae. PMID:19269434

  14. 微波消解-高分辨连续光源原子吸收光谱法测定锁阳和韭菜籽中的重金属元素含量%Determination of Heavy Metal Elements in Cynomorium and Leek Seeds by High Resolution Continuum Source Atomic Absorption Spectrometry with Microwave Digestion

    胡玥; 丁玉竹; 高旭东; 李西波; 邵士俊

    2016-01-01

    The contents of heavy metals ( Cu, Pb, Cd, Cr, As, Hg) in Chinese herbal medicines ( cynomorium and leek seeds) were tested using microwave digestion-high resolution continuum source atomic absorption spectrometry ( HR-CS AAS) . The samples were digested by microwave digestion, and methods were developed for the determination of the contents of Cu by flame atomic absorption spectrometry, Pb, Cd and Cr by graphite furnace atomic absorption spectrometry, As and Hg by hydride generation atomic absorption spectrometry, respectively. The recoveries were 95. 61% ~100. 1%, the relative standard deviations ( RSDs) were 0. 8% ~3. 3%, and the correlation coefficients of R2 were 0. 999. The results showed that the contents of the above-mentioned heavy metal elements in cynomorium and leek seeds were all lower than the permitted values in the standard of “medicinal plants and preparation of green import industry standard” and National food safety standard “limited quantity of pollutants in food”. The established method are simple, rapid, accurate and reliable, and are successfully applied to analyze the contents of heavy metal elements in Chinese herbal medicines.%利用微波消解-高分辨连续光源原子吸收光谱法测定锁阳、韭菜籽两种中药材中铜( Cu)、铅( Pb)、镉( Cd)、铬( Cr)、砷( As)和汞( Hg)的含量.采用微波消解进行样品前处理,火焰原子吸收法测定其中的Cu含量,石墨炉原子吸收法测定Pb、Cd和Cr含量,氢化物发生原子吸收法测定As、Hg含量.方法线性关系良好,相关系数R2大于0.999,加标回收率为95.61%~100.1%,RSD为0.8%~3.3%,测得锁阳和韭菜籽中Cu、Pb、Cd、Cr、As和Hg的含量值均低于《药用植物及制剂进口绿色行业标准》和食品安全国家标准《食品中污染物限量》( GB2762-2012)中规定的限量指标.方法分析速率快、干扰少、精密度高,适用于中药材中重金属含量的测定.

  15. 微波消解-火焰原子吸收光谱法测定氧化铝中的氧化钠%Determination of Sodium Oxide in Aluminum Oxide by Microwave Digestion-flame Atomic Absorption Spectrometry

    薛心禄

    2012-01-01

    氧化铝中氧化钠含量的测定,一般采用高温熔结,用水浸出钠盐后,用原予吸收火焰光度法测定,该方法的测定周期比较长,而且高温熔结时对铂金皿的损耗比较大。文章提出了试样用磷酸和硫酸混合溶液,在高压微波消解器中进行处理,将样品在较短的时间内消解,并在试液中加入一定量的氯化铯,消除钠的电离干扰,采用原子吸收光谱法直接测定,测试结果与标准样品推荐值比较,结果令人满意。%The sodium oxide content in aluminum oxide is usually determined by atomic absorption spectrophotometry with high temperature melting and leaching, which is time consuming and damage platinum bowl. The paper proposed forward to determine with sample of mixed phosphoric acid and sulfuric acid solution to process in the high pressure microwave digestion device. The samples were digested in a relatively short time, and added a certain amount of cesium chloride in the test solution. Used for eliminate ionization interference of sodium to directly determine sodium oxide in aluminum oxide by Atomic Absorption Spectrophotometer. Under the comparison of test results and recommended values of standard samples, it was satisfactory.

  16. Padronização interna em espectrometria de absorção atômica Internal standardization in atomic absorption spectrometry

    Kelly G. Fernandes; Mercedes de Moraes; José A. Gomes Neto; Joaquim A. Nóbrega; Pedro V. Oliveira

    2003-01-01

    This paper describes a review on internal standardization in atomic absorption spectrometry with emphasis to the systematic and random errors in atomic absorption spectrometry and applications of internal standardization in flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry. The rules for selecting an element as internal standard, limitations of the method, and some comments about the application of internal standardization in atomic absorption spectrometry...

  17. Determination of Lead in the Tea by Microwave Digestion-Graphite Furnace Atomic Absorption Spectrometry%微波消解-石墨炉原子吸收法测定茶叶中的铅

    殷锡峰; 何国柱; 吴龑

    2012-01-01

    采用微波消解系统处理样品,石墨炉原子吸收光谱法测定茶叶中的铅,可以大大减少消化试剂的用量及样品的处理时间,减少干扰,准确度高。铅的测定结果相对标准偏差为2.6%-5.1%;检出限为0.082mg/kg。%Tea samples treated with Microwave digestion system can greatly reduces magnitude of digestant, and decrease its processing time. Pb in Tea was determined by graphite furnace atomic absorption spectrom- etry.The method is rapid, simple and accuracy. The relative standard deviation of lead was 2.6%-5.1%, the detection limit was 0.082mg/kg.

  18. Self-absorption corrections in gamma-ray spectrometry applied to norm industrial samples

    High resolution gamma spectrometry is a versatile non-destructive radiometric technique that makes simultaneous determination of several radionuclides possible with little sample preparation. However, application of self-absorption corrections is a must, especially in the low energy range, if one hopes to obtain correct values of activity concentrations. Usually, NORM samples feature a wide variety of densities and composition, as opposed to the standards used in efficiency calibration, which are often water-based solutions. For that reason self-absorption effects must be considered individually in every sample. In this work an experimental and a semi-empirical method of self-absorption correction were applied to NORM samples and compared with each other in order to establish best practice in relation to the circumstances of an individual laboratory. Following the experimental methodology, transmission measurements of absorption factors with point sources were carried out, while the semi-experimental methodology involved the application of the EFFTRAN code, based on the 'efficiency transfer' principle. Both methods were validated by applying them to a set of spiked NORM matrices coming from the TiO2 industry located in the south-west of Spain in order to determine the flow of several radionuclides from the Uranium and Thorium series though the production process. The main advantages and disadvantages of the two approaches used are highlighted, focusing on the low energy range (46-200 keV). EFFTRAN qualities are its ease of use, its short-run time and good performance with samples of a well-known composition, while the transmission technique can be applied almost under any circumstances, providing that a suitable set of point sources covering the energy range of interest is at hand. (authors)

  19. Determination of Content of Plumbum in Anise by Microwave Digestion-Graphite Furnace-Atomic Absorption Spectrometry%微波消解-石墨炉原子吸收光谱法测定八角中铅的含量

    2013-01-01

      采用微波消解法处理八角样品、石墨炉原子吸收光谱法测定八角中铅的含量。此方法的线性范围为0~100.0 ng·mL-1(R=0.9993),加标回收率为95.24%~103.08%,相对标准偏差(RSD)为0.79%~2.61%(n=6)。该方法取样量少、准确度和精密度高,可作为检测八角中铅含量的方法,为食品安全提供可靠的测定技术保障。%Anise samples were dealt with microwave digestion,then the content of plumbum was determined by graphite furnace-atomic absorption spectrometry. The linear range of plumbum's absorption spectrometry was 0~100.0 ng·mL-1 (R=0.999 3). The adding standard recovery was 95.24%~103.08%. The RSD was 0.79%~2.61%(n=6). This method in which sampling quantity was little, with high accuracy and precision, could be used for detection of plumbum in anise and provided reliable technical support for food safety.

  20. Interferences from titanium and zirconium during calcium determination by flame spectrometry

    DIMITRIJE DJ. STOJANOVIC; JELENA S. MILINOVIC; SNEZANA D. NIKOLIC–MANDIC

    2007-01-01

    Titration methods based on an inhibition effect were used to investigate the interferences from Ti and Zr in the determination of Ca by atomic absorption and flame emission spectrometry using an air–acetylene flame. Changes either in the absorption or emission signal of Ca was continuously registered on a computer display and characteristic titration curves were obtained. The mole ratios between Ti or Zr and Ca at characteristic points on titration curves were used to explain the quantitative...

  1. Analysis of soil reference materials for vanadium(+5) species by electrothermal atomic absorption spectrometry

    Solid Certified Reference Materials (CRMs) with known vanadium(+5) content are currently not commercially available. Because of this, vanadium species have been determined in solid CRMs of soil, viz. CRM023-50, CRM024-50, CRM049-50, SQC001 and SQC0012. These CRMs are certified with only total vanadium content. Vanadium(+5) was extracted from soil reference materials with 0.1 M Na2CO3. The quantification of V(+5) was carried out by electrothermal atomic absorption spectrometry (ET-AAS). The concentration of V(+5) in the analyzed CRMs was found to be ranging between 3.60 and 86.0 μg g-1. It was also found that SQC001 contains approximately 88% of vanadium as V(+5) species. Statistical evaluation of the results of the two methods by paired t-test was in good agreement at 95% level of confidence.

  2. The coupling of rapidly synergistic cloud point extraction with thermospray flame furnace atomic absorption spectrometry

    Rapidly synergistic cloud point extraction (RS-CPE) was coupled with thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) to result in new CPE patterns and accelerated (1 min) protocols. It is demonstrated, for the case of copper (II) ion, that TS-FF-AAS improves the sampling efficiency and the sensitivity of FAAS determinations. Problems of nebulization associated with previous methods based on the coupling of FAAS and RS-CPE are overcome. TS-FF-AAS also improves sensitivity and gives a limit of detection for copper of 0.20 μg L-1, which is better by a factor of 32. Compared to direct FAAS, the factor is 114. (author)

  3. Monte Carlo study of characteristics of uranium L-edge from X-ray absorption spectrometry

    Park, Seunghoon; Kwak, Sung-Woo; Shin, Jung-Ki; Kang, Han-Byeol; Chung, Heejun [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

    2015-05-15

    L-edge densitometry (LED) which is specially called X-ray