WorldWideScience

Sample records for absorption spectrometric determinations

  1. Spectrofluorimetric, Atomic Absorption Spectrometric and Spectrophotometric Determination of Some Fluoroquinolones

    Hesham Salem

    2005-01-01

    Simple, accurate, sensitive and selective spectrofluorimetric, atomic absorption spectrometric and spectrophotometric methods are described for the quantitative determination of ten fluoroquinolones (amifloxacin, ciprofloxacin hydrochloride, difloxacin hydrochloride, enoxacin, enrofloxacin, lomefloxacin hydrochloride, levofloxacin, norfloxacin, ofloxacin and pefloxacin mesylate). The first method was a spectrofluorimetric method in which samples of the studied drugs in 0.1 N H2SO4 showed nati...

  2. Spectrofluorimetric, Atomic Absorption Spectrometric and Spectrophotometric Determination of Some Fluoroquinolones

    Hesham Salem

    2005-01-01

    Full Text Available Simple, accurate, sensitive and selective spectrofluorimetric, atomic absorption spectrometric and spectrophotometric methods are described for the quantitative determination of ten fluoroquinolones (amifloxacin, ciprofloxacin hydrochloride, difloxacin hydrochloride, enoxacin, enrofloxacin, lomefloxacin hydrochloride, levofloxacin, norfloxacin, ofloxacin and pefloxacin mesylate. The first method was a spectrofluorimetric method in which samples of the studied drugs in 0.1 N H2SO4 showed native fluorescence at 450 nm when excitation was at 290 nm. The calibration graph was rectilinear from 0.3-1.4 μg mL-1 (method I. Cobalt sulphate was used for precipitation of the ion associates formed from the reaction with the cited drugs. The formation and solubility of the solid complexes at the optimum conditions of pH and ionic strength values have been studied. The method depends on direct determination of the ions in the precipitate or indirect determination of the ions in the filtrate by atomic absorption spectroscopy. The optimum conditions for precipitation were carefully studied. Rectilinear calibration graphs were obtained in the range of 3-30 μg mL-1 for each of the investigated drugs. The molar ratios of the formed chelats were determined by Job's method and their association constants were also calculated (method II. Ammonium vanadate was used for the spectrophotometric determination of the selected fluoroquinolones by oxidation in sulphuric acid medium resulting in the development of a greenish blue colour measured at 766 nm which was attributed to the vanadium (IV produced by reduction of vanadium (V by the selected drugs. The optimum conditions for heating time, reagent concentration and sulphuric acid concentration were carefully studied. The accuracy and precision of the proposed method was confirmed by estimating five or six replicates within Beer's law limits were obtained in the range 10-40 μg mL-1 for each of the investigated drugs

  3. Atomic absorption spectrometric determination of mineral elements in mammalian bones

    The phosphorus content of the major bones of male and female selected mammals was determined using the yellow vanadomolybdate colorimetric method. For each animal, the bone with the highest phosphorus content was used as pilot sample. Varying concentrations of strontium were added to solutions of the ashed pilot samples to minimize phosphorus interference in the determination of calcium and magnesium using flame atomic absorption spectrophotometry operated on the air-acetylene mode. At least 6,000 ppm (0.6%) of strontium was required to give optimum results for calcium. The amount of magnesium obtained from the analysis was not affected by the addition of strontium. With the incorporation of strontium in the sample solution, all elements of interest can be determined in the same sample solution. Based on this, a procedure is proposed for the determination of calcium and other elements in bones. Average recoveries of spiked calcium and magnesium were 97.85% and 98.16%, respectively at the 95% confidence level. The coefficients of variation obtained for replicate determinations using one of the samples were 0.00% for calcium, lead and sodium, 2.93% for magnesium, 3.27% for iron and 3.92% for zinc at the concentration levels found in that sample. Results from the proposed procedure compared well with those from classical chemical methods at the 95% confidence level. It is evident that calcium phosphorus, magnesium and sodium which are the most abundant elements in the bones are distributed in varying amounts both in the different types of bones and different animal species, although the general trend is Ca > P > Na > Mg for each bone considered. The calcium - phosphorus ratio is generally 3:1. The work set out to propose an atomic absorption spectrometric method for the multi-element analysis of mammalian bones with a single sample preparation and to study the distribution pattern of these elements in the bones. (Author)

  4. Electrothermal atomization atomic absorption spectrometric determination of trace metals in uranium-plutomium fuel materials

    Atomic absorption spectrometric methods using the electrothermal mode of atomization developed for the determination of Ag, Be, Ca, Cd, Cr, Co, Cu, Fe, Li, Mn, Na, Ni, Sn and Zn in (U, Pu) solution with 4% plutonium have been described. The carbon rod atomizer has been adapted for glove box operation to enable handling of plutonium containing solution samples. Multielement solution standards with graded concentrations of the analytes and fixed concentration of the matrix are used in the standardization process. Nanogram to sub-nanogram quantities of the analytes have been determined with a precision of better than 9% RSD using 5 μl of the sample aliquots. (orig.)

  5. Separation of trace antimony and arsenic prior to hydride generation atomic absorption spectrometric determination

    A separation method utilizing a synthetic zeolite (mordenite) was developed in order to eliminate the gas phase interference of Sb(III) on As(III) during quartz furnace hydride generation atomic absorption spectrometric (HGAAS) determination. The efficiency of the proposed separation method in the reduction of suppression effects of transition metal ions on As(III) signal was also investigated. Among the volatile hydride-forming elements and their different oxidation states tested (Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), and Te(VI)), only Sb(III) was found to have a signal depression effect even at low (μg l-1) concentrations under the experimental conditions employed. It has been shown that mordenite adsorbs Sb(III) quantitatively, even at a concentration of 1000 μg l-1, at pHs greater than two, and also, it reduces the initial concentrations of the transition metal ions to lower levels which can be tolerated in many studies. The adsorption of Sb(III) on mordenite follows the Freundlich isotherm and is endothermic in nature

  6. Atomic-absorption spectrometric determination of trace metals in zirconium and zircaloy by discrete sample nebulization

    A discrete sample nebulization technique was employed to determine trace metals in nuclear grade zirconium and Zircaloy by flame atomic-absorption spectrometry. With 10% (w/v) sample solutions, detection limits for Cd, Cu, Mn, Ni and Pb were 0.6, 2, 1, 3, and 10 μg/g. Micro standard-addition procedures and background correction were employed to minimize matrix interferences produced by the high salt content of the aspirated solutions. (author)

  7. Colorimetric and atomic absorption spectrometric determination of mucolytic drug ambroxol through ion-pair formation with iron and thiocyanate.

    Levent, Abdulkadir; Sentürk, Zühre

    2010-09-01

    Colorimetric and atomic absorption spectrometric methods have been developed for the determination of mucolytic drug Ambroxol. These procedures depend upon the reaction of iron(III) metal ion with the drug in the presence of thiocyanate ion to form stable ion-pair complex which extractable chloroform. The red-coloured complex was determined either colorimetrically at 510 nm or by indirect atomic absorption spectrometry (AAS) via the determination of the iron content in the formed complex. The optimum experimental conditions for pH, concentrations of Fe(3+) and SCN(-), shaking time, phase ratio, and the number of extractions were determined. Under the proposed conditions, linearity was obeyed in the concentration ranges 4.1x10(-6) - 5.7x10(-5) M (1.7-23.6 µg mL(-1)) using both methods, with detection limits of 4.6x10(-7) M (0.19 µg mL(-1)) for colorimetry and 1.1x10(-6) M (0.46 µg mL(-1)) for AAS. The proposed methods were applied for the determination of Ambroxol in tablet dosage forms. The results obtained were statistically analyzed and compared with those obtained by applying the high-performance liquid chromatographic method with diode-array detection. PMID:20426742

  8. An indirect atomic absorption spectrometric determination of ciprofloxacin, amoxycillin and diclofenac sodium in pharmaceutical formulations

    MAHMOUD MOHAMED ISSA

    2008-05-01

    Full Text Available A highly sensitive indirect atomic absorption spectrophotometric (AAS method has been developed for the determination of very low concentrations of ciprofloxacin, amoxycillin and diclofenac sodium. The method is based on the oxidation of these drugs with iron(III. The excess of iron(III was extracted into diethyl ether and then the iron(II in the aqueous layer was aspirated into an air–acetylene flame and determined by AAS. The linear concentration ranges were 25–400, 50–500 and 60–600 ng ml-1 for ciprofloxacin, amoxycillin and diclofenac sodium, respectively. The results were statistically compared with the official method using t- and f-test at p < 0.05. There were insignificant interferences from most of the excipients present. The intra- and inter-day assay coefficients of variation were less than 6.1 % and the recoveries ranged from 95 to 103 %. The method was applied for the analysis of these drug substances in their commercial pharmaceutical formulations.

  9. Atomic-absorption spectrometric determination of cobalt, nickel, and copper in geological materials with matrix masking and chelation-extraction

    Sanzolone, R.F.; Chao, T.T.; Crenshaw, G.L.

    1979-01-01

    An atomic-absorption spectrometric method is reported for the determination of cobalt, nickel, and copper in a variety of geological materials including iron- and manganese-rich, and calcareous samples. The sample is decomposed with HP-HNO3 and the residue is dissolved in hydrochloric acid. Ammonium fluoride is added to mask iron and 'aluminum. After adjustment to pH 6, cobalt, nickel, and copper are chelated with sodium diethyl-dithiocarbamate and extracted into methyl isobutyl ketone. The sample is set aside for 24 h before analysis to remove interferences from manganese. For a 0.200-g sample, the limits of determination are 5-1000 ppm for Co, Ni, and Cu. As much as 50% Fe, 25% Mn or Ca, 20% Al and 10% Na, K, or Mg in the sample either individually or in various combinations do not interfere. Results obtained on five U.S. Geological Survey rock standards are in general agreement with values reported in the literature. ?? 1979.

  10. Electrothermal atomic absorption spectrometric determination of total and hexavalent chromium in atmospheric aerosols

    A method was developed which allow separate determination of Cr(VI) and total Cr from the same minute sample of atmospheric aerosols. Cr(VI) was leached was with 0.1 M Na2CO3 and the total Cr concentrations were determined after acid digestion. The method was validated by the analysis of certified reference materials, CRM 545, Mess-3 and Pacs-2 with good agreement between certified and found values. Cr concentrations in air samples taken around the chromium smelter show concentrations that exceed the maximum allowed levels in 8 h with higher values closer to the smelter. The limit of detection (LOD) of the method for Cr(VI) determination in air samples was found to be 0.2 ng m-3, i.e. lower than offered by the commonly preferred spectrophotometric and colorimetric techniques

  11. Flame atomic absorption spectrometric determinations of some trace metals after coprecipitation with gold-APDC

    Complete text of publication follows. For the determination of trace metals in various samples, preconcentration is an inevitable step to overcome interferences. Among various techniques for the separation of trace metals proposed until now, coprecipitation is one of the most useful ones. Many different coprecipitation procedures including use of organic and inorganic collectors have been developed. So far, in the literature, it is reported that APDC, NaDDTC, PAN, TAR, Oxine, etc. as chelating agent for metal-chelate collector have been extensively used for coprecipitation of trace metals. However, metal chelates, especially dithocarbamates, as collectors are ideal for their sensitivities, simplicities and tolerances to interferences.Therefore, in the present work, fundamental studies on the coprecipitation with gold/APDC chelate have been carried out for determination of trace metals in environmental samples by FAAS with microinjection. According to our literature survey, gold/APDC is not used for the coprecipitation of heavy metal ions, until now. In this work, the coprecipitation was carried out in a centrifuge tube. Firstly, the main factors, such as amount of coprecipitant reagent and carrier element, pH of the solution, standing time, sample volume and diverse ions, affecting the coprecipitation of some trace metals were evaluated. Under optimized conditions, the recoveries of Cu, Ni, Pb and Cd were ≥ 95 %. R.S.D. values for ten replicates were lower than 5.0 %. Preconcentration factors were found to be 20. The coprecipitation was applied to various water samples and non-alcoholic beverage.

  12. Determination of trace elements in Egyptian cane sugar (Deshna Factories) by neutron activation, atomic absorption spectrophotometric and inductively coupled plasma-atomic emission spectrometric analysis

    Multielement instrumental neutron activation (INAA), inductively coupled plasma-atomic emission spectrometric (ICP-AES) and atomic absorption spectrophotometric (AAS) analyses were utilized for the determination of Ag, Al, As, Au, Ba, Be, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Eu, Fe, Ga, Hf, K, La, Li, Lu, Mg, Mn, Na, Nb, Ni, P, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Th, Ti, U, V, W and Zn in sugar cane plant, raw juice, juice in different stages, syrup, deposits, molasses, A, B and C sugar, refinery 1 and 2 sugar, and in soil samples picked up from the immediate vicinity of the cane plant roots at surface, 30 and 60 cm depth, respectively. (author)

  13. Flame atomic absorption spectrometric determination of trace cadmium in alloys and biological samples after solid-liquid extraction and preconcentration with use of nitroso-S

    Cadmium is quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S) and tetradecyldimethylbenzylammonium chloride (TDBA) on microcrystalline naphthalene in the pH range 5.7-10.5 from a large volumes of aqueous solutions of various samples. After filtration, the solid mass consisting of cadmium complex and naphthalene is dissolved with 5 mL of dimethylformamide and the metal was determined by flame atomic absorption spectrometric. Cadmium complex can alternatively be quantitatively adsorbed on tetradecyldimethylbenzylammonium-naphthalene adsorbent packed in a column and determined similarly. About 25 ng of cadmium can be concentrated in a column from 500 mL of aqueous sample, where its concentration is as low as 0.05 ng/mL. Eight replicate determinations of 0.1 μg/mL of cadmium in final DMF solution gave a mean absorbance of 0.060 with a relative standard deviation of 1.8 %. The sensitivity for 1 % absorption was 7.3 ng/mL. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of cadmium in various alloys and biological samples. (author)

  14. Development of a cloud point extraction and preconcentration method for Cd and Ni prior to flame atomic absorption spectrometric determination

    Manzoori, Jamshid L. [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)]. E-mail: manzoori@tabrizu.ac.ir; Karim-Nezhad, Ghasem [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2004-09-13

    In this work a new cloud point extraction (CPE) methodology was developed for the separation and preconcentration of cadmium and nickel. The analyte in the initial aqueous solution was complexed with dithizone and Triton X-114 was added as surfactant. After phase separation, based on the cloud point of the mixture, and dilution of the surfactant-rich phase with tetrahydrofuran (THF), the enriched analytes were determined by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions and preconcentration of only 10 ml of sample in the presence of 0.05% Triton X-114, the enhancement factors of 52 and 39 and the detection limits of 0.31 {mu}g l{sup -1} and 1.2 {mu}g l{sup -1} were obtained for cadmium and nickel respectively. The proposed method was applied satisfactorily to the determination of cadmium and nickel in water samples.

  15. Standard test method for graphite furnace atomic absorption spectrometric determination of lead and cadmium extracted from ceramic foodware

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers procedures for using graphite furnace atomic absorption spectroscopy (GFAAS) to quantitatively determine lead and cadmium extracted by acetic acid at room temperature from the food-contact surface of foodware. The method is applicable to food-contact surfaces composed of silicate-based materials (earthenware, glazed ceramicware, decorated ceramicware, decorated glass, and lead crystal glass) and is capable of determining lead concentrations greater than 0.005 to 0.020 g/mL and cadmium concentrations greater than 0.0005 to 0.002 g/mL, depending on instrument design. 1.2 This test method also describes quality control procedures to check for contamination and matrix interference during GFAAS analyses and a specific sequence of analytical measurements that demonstrates proper instrument operation during the time period in which sample solutions are analyzed. 1.3 Cleaning and other contamination control procedures are described in this test method. Users may modify contamination cont...

  16. Multi-element coprecipitation for separation and enrichment of heavy metal ions for their flame atomic absorption spectrometric determinations

    A preconcentration-separation technique for lead(II), cadmium(II), chromium(III), nickel(II) and manganese(II) ions has been established. The procedure is based on coprecipitation of these ions by the aid of Cu(II)-dibenzyldithiocarbamate precipitate. The precipitate was dissolved in 0.5 mL of concentrated HNO3, and made up to 5 mL with distilled water. The heavy metals were determined by flame atomic absorption spectrometer. The effects of analytical parameters like pH, amounts of reagents, sample volume, etc. on the recoveries of heavy metals were investigated. The influences of matrix ions were also examined. The detection limits for the heavy metals based on 3 sigma (N = 21) were found in the range of 0.34-0.87 μg L-1. In order to validate the proposed method, two certified reference materials of NIST SRM 2711 Montana soil and NIST SRM 1515 Apple leaves were analyzed with satisfactory results. The proposed method was applied for the determination of lead, cadmium, chromium, nickel and manganese in environmental samples

  17. Graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples stabilized as microemulsion using conventional and permanent modifiers

    A procedure for the graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples was developed. Sample stabilization was necessary because of evident analyte losses that occurred immediately after sampling. Excellent long-term sample stabilization was observed by mixing different organic solvents with propan-1-ol and 50% vol/vol HNO3 at a 3.3:6.5:1 volume ratio. For Pb, efficient thermal stabilization was obtained using aqueous Pd-Mg modifier as well as for Ir as permanent modifier. The drying temperature and ramp rate influenced the sensitivity obtained for Ni, and had to be carefully optimized. Taking this into account, the same sensitivity was attained in all investigated organic media stabilized as microemulsion. Thus, calibration with microemulsions prepared with a single organic solvent was possible, using aqueous or organic stock solutions. Commercial gasoline and diesel samples were directly analyzed after stabilization as microemulsion and by comparative UOP procedures. n-Hexane microemulsions were used for calibration, and good agreement was obtained between the results using the proposed and comparative procedures. Typical coefficients of variation (n = 6) ranged from 1% to 4%, and from 1% to 3% for Ni and Pb, respectively. Detection limits (k = 3) in the original gasoline or diesel samples, derived from 10 blank measurements, were 4.5 and 3.6 μg l-1 for Ni and Pb, respectively, comfortably below the values found in the analyzed samples

  18. Flame atomic absorption spectrometric determination of cadmium(II) and lead(II) after their solid phase extraction as dibenzyldithiocarbamate chelates on Dowex Optipore V-493

    An enrichment procedure for cadmium and lead after their solid phase extraction as dibenzyldithiocarbamate chelates on Dowex Optipore V-493 has been established prior to their flame atomic absorption spectrometric determinations. The analytical parameters including pH, amounts of dibenzyldithiocarbamate, sample volume, etc., were investigated. The effects of alkaline and earth alkaline ions and some metal ions on the retentions of analytes on Dowex Optipore V-493 resin were examined. Under the optimized conditions, the detection limits (3s, n = 21) for cadmium and lead were 0.43 μg L-1 and 0.65 μg L-1, respectively. The relative standard deviation (R.S.D.), and the recoveries of standard addition for this method were lower than 5% (n = 11) and 95-102%, respectively. Three standard reference samples (LGC 6010 Hard drinking water, NIST SRM 2711 Montana soil and GBW 07605 Tea) were introduced for accuracy and precision of analytical data. The proposed solid phase extraction system was successfully applied to the analysis of environmental samples

  19. Graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples stabilized as microemulsion using conventional and permanent modifiers

    Reyes, Mariela N. Matos; Campos, Reinaldo C.

    2005-06-01

    A procedure for the graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples was developed. Sample stabilization was necessary because of evident analyte losses that occurred immediately after sampling. Excellent long-term sample stabilization was observed by mixing different organic solvents with propan-1-ol and 50% vol/vol HNO 3 at a 3.3:6.5:1 volume ratio. For Pb, efficient thermal stabilization was obtained using aqueous Pd-Mg modifier as well as for Ir as permanent modifier. The drying temperature and ramp rate influenced the sensitivity obtained for Ni, and had to be carefully optimized. Taking this into account, the same sensitivity was attained in all investigated organic media stabilized as microemulsion. Thus, calibration with microemulsions prepared with a single organic solvent was possible, using aqueous or organic stock solutions. Commercial gasoline and diesel samples were directly analyzed after stabilization as microemulsion and by comparative UOP procedures. n-Hexane microemulsions were used for calibration, and good agreement was obtained between the results using the proposed and comparative procedures. Typical coefficients of variation ( n = 6) ranged from 1% to 4%, and from 1% to 3% for Ni and Pb, respectively. Detection limits ( k = 3) in the original gasoline or diesel samples, derived from 10 blank measurements, were 4.5 and 3.6 μg l - 1 for Ni and Pb, respectively, comfortably below the values found in the analyzed samples.

  20. Determination of Cr(VI) in welding fumes by anion-exchange fast protein liquid chromatography with electrothermal atomic absorption spectrometric detection.

    Milacic, Radmila; Scancar, Janez; Tusek, Janez

    2002-02-01

    The applicability of an anion-exchange fast protein liquid chromatographic-electrothermal atomic absorption spectrometric procedure (FPLC-ETAAS) was investigated for the determination of Cr(VI) in welding fumes after alkaline extraction of aerosols loaded on filters. Gas tungsten arc welding (GTAW) of stainless steel was applied. Samples of welding fumes were collected during regular welding on polycarbonate membrane filters of 8 microm and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction (2% NaOH-3% Na2CO3) of filters in a heated ultrasonic bath was applied to leach Cr from the airborne particulate matter. 0.5 cm3 of sample extract was then injected onto an anion-exchange FPLC column. Tris-HCl buffer (0.005 mol dm(-3), pH 8.0) and the same buffer with NaCl (0.5 mol dm(-3)) were employed in gradient elution (15 min, flow rate 1 cm3 min(-1)). The separated Cr species were determined "off line" by ETAAS in 0.5 cm3 fractions. Cr(VI) was reproducibly and quantitatively eluted from 12.0 to 13.0 min with a maximum peak at 12.5 min. Good repeatability of measurement (+/-3.0%) of alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.035 microg m(-3) Cr(VI), when 2 m3 of aerosols were collected on the filter. Validation of the procedure was performed by spiking alkaline extracts and by the analysis of standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. The technique was successfully applied for the determination of Cr(VI) in welding fumes. PMID:11939630

  1. Cloud Point Extraction and Flame Atomic Absorption Spectrometric Determination of Lead, Cadmium and Palladium in Some Food and Biological Samples

    M. Soylak

    2011-12-01

    Full Text Available The proposed method is based on the complexation of the Pb2+, Cd2+ and Pd2+ ions with 3-(1-(1-H-Indol-3-Yl-3-phenylallyl-1H-indole (IPAI at pH 8.0 in the presence of Triton X-114. The phase separation occured when micellar solution was heated at 55 ◦C. The surfactant-rich phase, diluted to 0.5 mL via 1.0 mol L−1 nitric acid in methanol was directly introduced into the nebulizer of the flame atomic absorption spectrometry (FAAS. Influence of variables such as pH, amount of ligand and Triton X-114, heating time and temperature were evaluated and optimized. The optimized enhancement factors for Pb2+, Cd2+ and Pd2+ ions were 22, 33 and 23, respectively and the detection limit (DLs was between of 1.6–2.6 µgL−1. The relative standard deviation (RSD of each ion was found to be less than 4.6% at 100 µgL−1. In addition, the calibration graphs were linear in the range of 0.01-0.22 μg mL−1 for Cd2+ ion, 0.018-0.26 μg mL−1 for Pb2+ ion and 0.02-0.27 μg mL−1 for Pd2+ ion with the correlation coefficients in the range of 0.995–0.999.

  2. Electrothermal atomic absorption spectrometric determination of lithium, sodium, potassium and copper in uranium without preliminary chemical separation

    Graphite furnace atomization is used for the direct determination of Li (0.25-4 ppm), Na (8-70 ppm), K (20-300 ppm) and Cu (0.5-25 ppm) in uranium dissolved in nitric acid, with relative standard deviations of 4-9%. Only iron seriously depresses the signals from the alkali metals. (Auth.)

  3. Biosorption of platinum and palladium for their separation/preconcentration prior to graphite furnace atomic absorption spectrometric determination

    Inexpensive baker's yeast Saccharomyces cerevisiae and green algae Chlorella vulgaris, either free or immobilized on silica gel have been shown to selectively accumulate platinum and palladium from water samples in acidic medium (pH 1.6-1.8). Optimization of conditions of metals biosorption (sample pH, algae and yeast masses, adsorption time, temperature) was performed in batch mode. The procedure of matrix separation based on biosorption of platinum and palladium on algae C. vulgaris covalently immobilized on silica gel in flow mode was developed. The use of algae in flow procedure offers several advantages compared with its use in the batch mode. The procedure shows better reproducibility (-1 thiourea in 1 mol l-1 hydrochloric acid. The influence of thiourea on analytical signals of examined metals during GFAAS determination is discussed. The procedure has been applied for separation of noble metals from tap and waste water samples spiked with platinum and palladium

  4. Novel atomic absorption spectrometric and rapid spectrophotometric methods for the quantitation of paracetamol in saliva: Application to pharmacokinetic studies

    Issa M

    2008-01-01

    Full Text Available A novel atomic absorption spectrometric method and two highly sensitive spectrophotometric methods were developed for the determination of paracetamol. These techniques based on the oxidation of paracetamol by iron (III (method I; oxidation of p-aminophenol after the hydrolysis of paracetamol (method II. Iron (II then reacts with potassium ferricyanide to form Prussian blue color with a maximum absorbance at 700 nm. The atomic absorption method was accomplished by extracting the excess iron (III in method II and aspirates the aqueous layer into air-acetylene flame to measure the absorbance of iron (II at 302.1 nm. The reactions have been spectrometrically evaluated to attain optimum experimental conditions. Linear responses were exhibited over the ranges 1.0-10, 0.2-2.0 and 0.1-1.0 µg/ml for method I, method II and atomic absorption spectrometric method, respectively. A high sensitivity is recorded for the proposed methods I and II and atomic absorption spectrometric method value indicate: 0.05, 0.022 and 0.012 µg/ml, respectively. The limit of quantitation of paracetamol by method II and atomic absorption spectrometric method were 0.20 and 0.10 µg/ml. Method II and the atomic absorption spectrometric method were applied to demonstrate a pharmacokinetic study by means of salivary samples in normal volunteers who received 1.0 g paracetamol. Intra and inter-day precision did not exceed 6.9%.

  5. Determination of Palladium in Resin by Lead Fire Assaying-Flame Atomic Absorption Spectrometric Method%铅试金富集-火焰原子吸收光谱法测定树脂中钯

    王芳; 陈小兰; 林海山; 李小玲; 肖红新

    2013-01-01

    通过铅试金富集树脂中的钯并用银作钯灰吹保护,得到的银钯合粒用王水溶解,在5%的盐酸介质中,采用原子吸收光谱法测定钯,该法测钯的相对标准偏差RSD为0.53%,加标回收率在99.04%~100.10%之间。%Palladium in resin was enriched by lead assaying, using silver as a protective agent to produce silver-palladium alloy, and then the alloy was dissolved in aqua regia. Air acetylene flame atomic absorption spectrometric method was used to determinate palladium in 5%hydrochloric acid solution. The relative standard deviation (RSD) in determination of palladium is 0.53%and the recovery rate is between 99.04%~100.10%.

  6. A solid liquid extraction and preconcentration method for the atomic absorption spectrometric determination of trace cobalt in various alloys and biological samples

    Cobalt is quantitatively retained as cobalt-2-nitroso-4-sulfonic acid (nitros-S)-tetradecyldimethylbenzylammonium (TDBA+) ion-pair complex on microcrystalline naphthalene in the pH range 6.2-9.0 from a large volume of its aqueous solution of various complex samples. After filtration, the solid mass consisting of cobalt complex and naphthalene is dissolved in 5 ml of dimethylformamide (DMF) and the metal is determined by flame atomic absorption spectrometry (FAAS). Cobalt complex can alternatively be quantitatively adsorbed on tetradecyldimethylbenzylammonium chloride-naphthalene adsorbent packed in a column and determined similarly. The calibration curve is linear over the concentration range 0.2-11.5 μg of cobalt in 5 ml of the final DMF solution. In this case, 0.2 μg of cobalt may be concentrated in a column from 250 ml of aqueous sample where its concentration is as low as 0.8 ng/ml. Eight replicate determinations of 3.0 μg of cobalt in the final DMF solution give a mean absorbance of 0.045 with a relative standard deviation of 1.8%. The sensitivity for 1% absorption is 59 ng/ml. The interference of a large number of anions and cations on the determination of cobalt has been studied and the optimum conditions developed utilized for its trace determination in various alloys and biological samples. The method may also be used for the determination of cobalt in some environmental samples

  7. Graphite furnace and hydride generation atomic absorption spectrometric determination of cadmium, lead, and tin traces in natural surface waters: Study of preconcentration technique performance

    In this study three major types of preconcentration methods based upon different principles (cation exchange, physical absorption and hydrophobic extraction) were evaluated and optimized for the extraction and determination of three highly toxic heavy metals namely Cd, Pb and Sn by graphite furnace and hybrid generation atomic absorption spectrometry in real samples. The optimum analytical conditions were examined and the analytical features of each method were revealed and compared. Detection limits as low as 0.003-0.025 μg L-1 for Cd2+, 0.05-0.10 μg L-1 for Pb2+ and 0.1-0.25 μg L-1 for Sn4+ depending on the extraction method were obtained with RSD values between 3.08% and 6.11%. A preliminary assessment of the pollution status of three important natural ecosystems in Epirus region (NW Greece) was performed and some early conclusions were drawn and discussed

  8. Preconcentration and atomic absorption spectrometric determination of cadmium, cobalt, copper, iron, lead, manganese, nickel and zinc in water samples using 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone

    The reagent 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone (MPAPT) has been examined for the pre-concentration of metal ions and determination using air acetylene flame atomic absorption spectrometer. The method is based on the complexation and extraction of cadmium (II), cobalt(III), copper(II), lead(II), nickel(II), iron(II), iron(II), manganese(II) and zinc(II) in chloroform. The metal iron are back extracted in nitric acid (1:1) or after evaporation of solvent the residue is digested in nitric acid. After necessary adjustment of volume the metal ions were determined in aqueous solution. Pre-concentration is obtained 10-25 times. Metal ions recovery was 95.4-100.8% with coefficient of variation 0.2-7.5%. The method used for the determination of metals in canal and sewerage waters, within 2-6433 mu g/L with C. V 0.-5.2%. (author)

  9. Inclusion of riboflavin in β-cyclodextrin: A fluorimetric and absorption spectrometric study

    Roy, Dalim Kumar; Deb, Nipamanjari; Ghosh, Bankim Chandra; Mukherjee, Asok K.

    2009-07-01

    Formation of inclusion complexes between riboflavin and β-cyclodextrin (β-CD) with both 1:1 and 1:2 stoichiometry has been established by fluorimetric titration. However, in absorption spectrometric experiment, spectral change of riboflavin in the visible range could be observed only by taking β-CD at a much higher concentration (about 100 times) than riboflavin and under such condition only 1:2 complexes could be detected. Its formation constant ( K) was determined by a multiple linear regression analysis of the absorption data. The reliability of the K value was confirmed by the consistency achieved on analyzing the data at two different wavelengths.

  10. Atomic absorption spectrometric determination of some metal ions after preconcentration by solid phase extraction using amberlite XAD 16 resin loaded with thenoyltrifluoroacetone

    Complete text of publication follows. The direct determination of extremely low concentrations of trace elements by modern atomic spectroscopic methods, such as atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry is often difficult because of insufficient sensitivity and selectivity of the methods used. For this reason, the preliminary separation and preconcentration of trace elements from the matrix are often required. Solid phase extraction shows several major advantages such as simplicity, rapidity and high enrichment factor, the ability of combination with different detection techniques in the form of on-line or off-line mode and finally cost saving (Tokalioglu et al., Microchim Acta 164 (2009) 471-477.). A new solid phase extraction method for the separation and preconcentration of Cu(II), Pb(II), Ni(II), Co(II), Mn(II) and Fe(III) ions was developed. As solid phase material, Amberlite XAD-16 resin loaded with thenoyltrifluoroacetone (TTA) was used. For this purpose, 0.5 g of the resin was saturated with 10 mL of 0.5% (w/v) TTA solution. After preconcentrating, the metals retained on the resin were eluted with 10 mL of 2 mol L-1 HCl and then determined by flame atomic absorption spectrometry. The effect of some parameters for the preconcentration of the metal ions was investigated. The optimum pH was found as 6. Eluent for quantitative elution was 10 mL of 2 mol L-1 HCl.

  11. Atomic-absorption spectrometric, neutron-activation and radioanalytical techniques for the determination of trace metals in environmental, biochemical and toxicological research

    Radioanalytical techniques and atomic-absorption spectrometry have been used for the micro-determination of vanadium in biological specimens such as human tissues and body fluids in environmental, biochemical and toxicological research. The use of 48V as a radiotracer permitted investigations on the vaporisation and retention mechanisms of vanadium. Higher vanadium oxides are probably converted into lower oxides, decomposing to VO in gaseous form, followed by the dissociation to 'free vanadium' and oxygen. It was found that about 20% of the 48V radioactivity was consistently retained in the graphite tube after 10 repeated introductions and firings of 50 μl of 50 ng ml-148V-labelled vanadium solution. However, the amount retained, probably in the form of carbide, does not vaporise under the conditions used for the analysis. Determinations of vanadium at the parts per billion level in 10 urine samples by neutron-activation analysis and by graphite furnace atomic-absorption spectrometry showed agreement that can be considered satisfactory for practical purposes. (author)

  12. Selective cloud point extraction and preconcentration of trace amounts of silver as a dithizone complex prior to flame atomic absorption spectrometric determination

    Manzoori, Jamshid L.; Karim-Nezhad, Ghasem

    2003-05-19

    Dithizone (diphenylthiocarbazone) was used as a complexing agent in cloud point extraction for the first time and applied for selective preconcentration of trace amounts of silver. The analyte in the initial aqueous solution was acidified with sulfuric acid (pH<1) and Triton X-114 was added as a surfactant. After phase separation, based on the cloud point separation of the mixture, the surfactant rich phase was diluted with tetrahydrofuran (THF) and the analyte determined in the enriched solution by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions, a preconcentration factor of 43 was obtained for only 10 ml of sample. The analytical curve was linear in the range of 3-200 ng ml{sup -1} and the limit of detection was 0.56 ng ml{sup -1}. The proposed method was applied to the determination of silver in water samples.

  13. The determination of trace amounts of heavy metals in waters by a flow-injection system including ion-exchange preconcentration and flame atomic absorption spectrometric detection

    The flow-injection system combines on-line ion-exchange preconcentration with atomic absorption spectrometry (a.a.s.) for the determination of traces (μg l-1) of heavy metals in water samples. A multifunctional rotary sampling valve which incorporated two parallel sampling columns allows sampling, exchange, elution and a.a.s. to be achieved sequentially. The increases in sensitivity for nickel, copper, lead and cadmium were 20-28-fold at a sampling rate of 40 h-1 with 5-ml samples. Relative standard deviations were 1.5-4.1%. The recoveries of these four metals added to tap, sea and polluted waters were generally satisfactory, except for cadmium in polluted water. The effects of column diameter and elution flow rates on sensitivity are discussed. Possible interferences are described. (Auth.)

  14. Flame atomic absorption spectrometric determination of trace amounts of heavy metal ions after solid phase extraction using modified sodium dodecyl sulfate coated on alumina

    A sensitive and selective solid phase extraction procedure for the determination of traces of Cu(II), Zn(II), Pb(II) and Fe(III) has been developed. An alumina-sodium dodecyl sulfate (SDS) coated on with meso-phenyl bis(indolyl) methane (MPBIM) was used for preconcentration and determination of Cu(II), Zn(II), Pb(II) and Fe(III) ions by flame atomic absorption spectrometry. The analyte ions were adsorbed quantitatively on adsorbent due to their complexation with MPBIM. Adsorbed metals were quantitatively eluted using 6 mL of 4 mol L-1 nitric acid. The effects of parameters such as pH, amount of alumina, amount of MBITP, flow rate, type and concentration of eluting agent were examined. The effects of interfering ions on the separation-preconcentration of analytes were also investigated. The relative standard deviation of the method was found to be less than 3.0%. The presented procedure was successfully applied for determination of analytes in real samples

  15. A biosorption system for metal ions on Penicillium italicum - loaded on Sepabeads SP 70 prior to flame atomic absorption spectrometric determinations

    A solid phase extraction (SPE) preconcentration system, coupled to a flame atomic absorption spectrometer (FAAS), was developed for the determination of copper(II), cadmium(II), lead(II), manganese(II), iron(III), nickel(II) and cobalt(II) ions at the μg L-1 levels on Penicillium italicum - loaded on Sepabeads SP 70. The analytes were adsorbed on biosorbent at the pH range of 8.5-9.5. The adsorbed metals were eluted with 1 mol L-1 HCl. The influences of the various analytical parameters including pH of the aqueous solutions, sample volume, flow rates were investigated for the retentions of the analyte ions. The recovery values are ranged from 95-102%. The influences of alkaline, earth alkaline and some transition metal ions were also discussed. Under the optimized conditions, the detection limits (3 s, n = 21) for analytes were in the range of 0.41 μg L-1 (cadmium) and 1.60 μg L-1 (iron). The standard reference materials (IAEA 336 Lichen, NIST SRM 1573a Tomato leaves) were analyzed to verify the proposed method. The method was successfully applied for the determinations of analytes in natural water, cultivated mushroom, lichen (Bryum capilare Hedw), moss (Homalothecium sericeum) and refined table salt samples

  16. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium(II), lead(II), palladium(II) and silver(I) in environmental samples

    Ghaedi, Mehrorang, E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Shokrollahi, Ardeshir [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Niknam, Khodabakhsh [Chemistry Department, Persian Gulf University, Bushehr (Iran, Islamic Republic of); Niknam, Ebrahim; Najibi, Asma [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2009-09-15

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I). The analytical procedure involved the formation of understudy metals complex with bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 1 mol L{sup -1} HNO{sub 3} was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions, the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL{sup -1} for Cd{sup 2+}, Pb{sup 2+}, Pd{sup 2+} and Ag{sup +} along with preconcentration factors of 30 and enrichment factors of 48, 39, 32 and 42 for Cd{sup 2+}, Pb{sup 2+}, Pd{sup 2+} and Ag{sup +}, respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as radiology waste, vegetable, blood and urine samples.

  17. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium(II), lead(II), palladium(II) and silver(I) in environmental samples

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I). The analytical procedure involved the formation of understudy metals complex with bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 1 mol L-1 HNO3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions, the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL-1 for Cd2+, Pb2+, Pd2+ and Ag+ along with preconcentration factors of 30 and enrichment factors of 48, 39, 32 and 42 for Cd2+, Pb2+, Pd2+ and Ag+, respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as radiology waste, vegetable, blood and urine samples.

  18. Development of on-line single-drop micro-extraction sequential injection system for electrothermal atomic absorption spectrometric determination of trace metals

    A novel automatic sequential injection (SI) single-drop micro-extraction (SDME) system is proposed as versatile approach for on-line metal preconcentration and/or separation. Coupled to electrothermal atomic absorption spectrometry (ETAAS) the potentials of this SI scheme are demonstrated for trace cadmium determination in water samples. A non-charged complex of cadmium with ammonium diethyldithiophosphate (DDPA) was produced and extracted on-line into a 60 μL micro-drop of di-isobutyl ketone (DIBK). The extraction procedure was performed into a newly designed flow-through extraction cell coupled on a sequential injection manifold. As the complex Cd(II)-DDPA flowed continuously around the micro-droplet, the analyte was extracting into the solvent micro-drop. All the critical parameters were optimized and offered good performance characteristics and high preconcentration ratios. For 600 s micro-extraction time, the enhancement factor was 10 and the sampling frequency was 6 h-1. The detection limit was 0.01 μg L-1 and the precision (RSD at 0.1 μg L-1 of cadmium) was 3.9%. The proposed method was evaluated by analyzing certified reference material

  19. Electrothermal atomic absorption spectrometric determination of cadmium and lead in traces in aquatic systems following flotation by two chromium(III) collectors.

    Kormusoska, Natasa Bakreska; Cundeva, Katarina; Stafilov, Trajce

    2009-10-01

    A fast flotation method for determination of cadmium and lead in aquatic systems by two chromium(III) collectors is described. The first collector is a colloid precipitate of hydrated chromium(III) oxide, Cr2O3 x xH2O, while the second is a bulk chromium(III) pentamethylenedithiocarbamate, Cr(PMDTC)3. Cadmium and lead present in water are incorporated into the collector mass at pH 7.5 by addition of 20 mg of Cr(III) and 0.4 mmol of pentamethyleneammonium pentamethylenedithiocarbamate, PMA-PMDTC, to 0.5 L water sample. A solid precipitate was separated from the processed water system by air bubbles. After dissolving with strong acid, the solution is tested by electrothermal atomic absorption spectrometry (ETAAS). The limit of detection for Cd by flotation/ETAAS method is 0.002 microg L(-1), while for Pb is 0.04 microg L(-1). The precision of the method is expressed as relative standard deviations ranging of 5.0% for Cd (concentration range from 0.1 to 0.5 microg L(-1)) and 4.25% for Pb (concentration range from 0.5 to 5 microg L(-1)). The characteristic mass (mass that gives an integrated absorbance of 0.0044 s) of 1.06 pg for Cd and 16.7 pg for Pb were obtained. The method was validated by the standard additions and by its application to the reference materials (Surface water-SPS-SW-1, River Thames Water-LGC-6019). PMID:19847715

  20. On-line sequential injection dispersive liquid-liquid microextraction system for flame atomic absorption spectrometric determination of copper and lead in water samples.

    Anthemidis, Aristidis N; Ioannou, Kallirroy-Ioanna G

    2009-06-30

    A simple, sensitive and powerful on-line sequential injection (SI) dispersive liquid-liquid microextraction (DLLME) system was developed as an alternative approach for on-line metal preconcentration and separation, using extraction solvent at microlitre volume. The potentials of this novel schema, coupled to flame atomic absorption spectrometry (FAAS), were demonstrated for trace copper and lead determination in water samples. The stream of methanol (disperser solvent) containing 2.0% (v/v) xylene (extraction solvent) and 0.3% (m/v) ammonium diethyldithiophosphate (chelating agent) was merged on-line with the stream of sample (aqueous phase), resulting a cloudy mixture, which was consisted of fine droplets of the extraction solvent dispersed entirely into the aqueous phase. By this continuous process, metal chelating complexes were formed and extracted into the fine droplets of the extraction solvent. The hydrophobic droplets of organic phase were retained into a microcolumn packed with PTFE-turnings. A portion of 300 microL isobutylmethylketone was used for quantitative elution of the analytes, which transported directly to the nebulizer of FAAS. All the critical parameters of the system such as type of extraction solvent, flow-rate of disperser and sample, extraction time as well as the chemical parameters were studied. Under the optimum conditions the enhancement factor for copper and lead was 560 and 265, respectively. For copper, the detection limit and the precision (R.S.D.) were 0.04 microg L(-1) and 2.1% at 2.0 microg L(-1) Cu(II), respectively, while for lead were 0.54 microg L(-1) and 1.9% at 30.0 microg L(-1) Pb(II), respectively. The developed method was evaluated by analyzing certified reference material and applied successfully to the analysis of environmental water samples. PMID:19376348

  1. Selective solid phase extraction of platinum on an ion imprinted polymers for its electrothermal atomic absorption spectrometric determination in environmental samples

    An ion-imprinted polymer (IIP) was obtained by copolymerization of methacrylic acid (as a functional monomer) and ethylene glycol dimethacrylate (as a crosslinking agent) in the presence of various chelators for Pt(II) ion and using 2,2'-azo-bis-isobutyronitrile as the initiator. Specifically, acetaldehyde thiosemicarbazone (AcTSn) and benzaldehyde thiosemicarbazone (BnTSn) were used as chelators. The IIPs were applied as sorbents for solid-phase extraction of Pt(II) and Pt(IV) ions from aqueous solutions. The effects of acidity and flow rate of the sample, of elution conditions and of potentially interfering ions were investigated. The imprinting effect of analyte is clearly demonstrated by the fact that only the IIP is capable of quantitative retention of Pt(II) and Pt(IV) ions. The method works best in the pH range from 0.5 to 1 and from 3.5 to 9.5. The ions can be recovered with an acidic solution of thiourea. The Pt-AcTSn polymer displays better sorption properties for the separation of analytes. The selectivity coefficients of the Pt-AcTSn and control polymers for Pt(IV) in the presence Pd(II), Rh(III), Ru(III), Al(III) and Cu(II) were calculated, and the sorbent capacity for Pt(IV) was found to be 4.56 μg g-1. The method was successfully applied to the determination of Pt(IV) by electrothermal atomic absorption spectrometry in tap water, tunnel dust and anode slime samples. (author)

  2. Enrichment of trace amounts of copper(II) ions in water samples using octadecyl silica disks modified by a Schiff base ionophore prior to flame atomic absorption spectrometric determination

    Fathi, S.A.M. [Department of Chemistry, Faculty of Science, Zanjan University, PO Box 45195-313 Zanjan (Iran, Islamic Republic of); Yaftian, M.R. [Department of Chemistry, Faculty of Science, Zanjan University, PO Box 45195-313 Zanjan (Iran, Islamic Republic of)], E-mail: yaftian@znu.ac.ir

    2009-05-15

    Bis(5-bromo-2-hydroxybenzaldehyde)-1,2-propanediimine is synthesized by the reaction of 5-bromo-2-hydroxybenzaldehyde and 1,2-diaminopropane in ethanol. This ligand is used as a modifier of octadecyl silica disks for preconcentration of trace amounts of copper(II) ions, followed by nitric acid elution and flame atomic absorption spectrometric (FAAS) determination. The effect of parameters influencing the extraction efficiency, i.e. pH of the sample solutions, amount of the Schiff base, type and volume of stripping reagent, sample and eluent flow rates were evaluated. Under optimum experimental conditions, the capacity of the membrane disks modified by 4 mg of the ligand was found to be 247.7 ({+-}2.1) {mu}g of copper. The detection limit and the concentration factor of the presented method are 2.4 ng/l and greater than 400, respectively. The method was applied to the extraction, recovery and detection of copper in different synthetic and water samples.

  3. Separation and flame atomic absorption spectrometric determination of total chromium and chromium (III) in phosphate rock used for production of fertilizer.

    El-Sheikh, Amjad H; Al-Degs, Yahya S; Sweileh, Jamal A; Said, Adi J

    2013-11-15

    Due to the commercial value of phosphate rock (PR) as a fertilizer precursor, it is necessary to investigate its heavy metals content. Chromium (Cr) may present as Cr(III) or Cr(VI) in PR; but quantitative differentiation between them is not an easy task. This is due to possible interconversion of Cr species during the digestion/leaching process. In this work, ultrasound digestion (USD) of PR was optimized (300 mg PR, 4.0 mL of 4.0 mol L(-1) nitric acid, 15 min sonication) for the sake of leaching Cr species prior to their determination by flame atomic absorption spectroscopy. Using multi-walled carbon nanotube (MWCNT) as adsorbent, solid phase extraction (SPE) was used to separate Cr(III) from the digestate at pH 9, while total Cr was estimated after reducing Cr(VI) into Cr(III). The optimum USD/SPE method gave LOQ and LOD of Cr(III) of 0.96 mg kg(-1) and 0.288 mg kg(-1), respectively. The method sensitivity was 1.44×10(-3) AU kg mg(-1) within the studied Cr concentration range (5-400 mg kg(-1)). The USD/SPE method was validated by analyzing lake sediments LKSD-4 certified reference material, and by comparison with classical digestion method (CD). Application of USD/SPE on Jordanian PR samples gave total Cr rang 29.1-122.0 mg kg(-1) (±1.4-6.3), while Cr(III) ranged between 23.8 and 101.7 mg kg(-1) (±1.3-5.5). AFPC Rock Check Program samples gave total Cr range 238.9-394.7 mg kg(-1) (±11.5-24.1), while Cr(III) ranged between 202.4 and 335.8 mg kg(-1) (±11.4-18.3). These results were very close to the results obtained by the CD method. PMID:24148433

  4. Cloud point extraction and flame atomic absorption spectrometric determination of trace lead in freshwater fish%浊点萃取-火焰原子吸收光谱法测定淡水鱼中痕量铅

    王秀峰; 李龙; 张春丽; 林朋; 崔书亚

    2012-01-01

    采用以双硫腙为络合剂、Triton X- 100为表面活性剂的新型浊点萃取体系富集淡水鱼中的痕量铅,并用火焰原子吸收光谱法对其进行测定.探讨了溶液pH、表面活性剂浓度、络合剂用量、平衡温度、平衡时间等对浊点萃取及测定灵敏度的影响,优化了实验条件.在最佳条件下测得铅的检出限为0.090μg/L,校准曲线相关系数为0.9999.该方法已用于淡水鱼中痕量铅的测定.%A new cloud point extraction-flame atomic absorption spectrometric method has been developed to determine trace lead. Dithizone was selected as the complex reagent and Triton X - 100 as the surfactant. Effects of pH, concentrations of surfactant and complex reagent, equilibrium temperature and time on the efficiency and sensitivity of cloud point extraction were investigated. Under optimal conditions, the calibration curve was linear over the concentration range of 0. 1 - 60μg/L with correlation coefficient of 0. 9999 and detection limit of 0. 090 μg/L. The present method was applied to the determination of trace lead in freshwater fish samples with satisfactory results.

  5. Flame atomic absorption spectrometric determination of μg amounts of Fe (III) ions after solid phase extraction using modified octadecyl silica membrane disks

    A simple, rapid and reliable method has been developed to selectively separate and concentrate ultra trace amounts of Fe (III) ions from aqueous samples for the measurement by flame atomic absorption spectrometry (FAAS). By the passage of aqueous samples through an octadecyl silica membrane disk modified by a recently synthesized Schiff base (Bis-(4-nitro phenyl azo) salisilidine-1,3-diamino propane), Fe(III) ions adsorb quantitatively and most of matrix elements will pass through the disk to drain. The retained iron ions are then stripped from the disk by minimal amount of 0.1 mol l-1 sulfuric acid as eluent. Extraction efficiency and the influence of pH, flow rates, amount of ligand, type and least amount of stripping acid as eluent were evaluated. The recovery of the iron from aqueous solution on the membrane disk modified with 3 mg Schiff's base was quantitative over pH 2-4.5. The linear dynamic range of the proposed method for Fe (III) ions was found in a wide concentration range of 0.20 (± 0.05)-680 (± 2) μg l-1. The detection limit and preconcentration factor of this solid phase extraction method were found 20.0 (± 0.7) ng l-1 and 100 respectively. The reproducibility of the procedure is at the most 1.5%

  6. Bi(III)4-methylpiperidinedithiocarbamate coprecipitation procedure for separation-pre-concentration of trace metal ions in water samples by flame atomic absorption spectrometric determination

    A pre-concentration method was developed for determination of trace amounts of cadmium, copper and lead in water samples by FAAS after coprecipitation by using potassium 4-methylpiperidinedithiocarbamate (K4-MPDC) as a chelating agent and Bi(III) as a carrier element. This procedure is based on filtration of the solution containing precipitate on a cellulose nitrate membrane filter following Cd(II), Cu(II) and Pb(II) coprecipitation with Bi(III)4-MPDC and then the precipitates together with membrane filter were dissolved in concentrated nitric acid. The metal contents of the final solution were determined by FAAS. Several parameters including pH of sample solution, amount of carrier element and reagent, standing time, sample volume for precipitation and the effects of diverse ions were examined. The accuracy of the method was tested with standard reference material (MBH, C31XB20 and CRM BCR-32) and Cd, Cu and Pb added samples. Determination of Cd, Cu and Pb was carried out in sea water, river water and tap water samples. The recoveries were >95%. The relative standard deviations of determination were less than 10%

  7. Flame Atomic Absorption Spectrometric Determination of Gold After Solid-Phase Extraction of Its 2-Aminobenzothiazole Complex on Diaion SP-207.

    Unsal, Yunus Emre; Tuzen, Mustafa; Soylak, Mustafa

    2016-03-01

    An SPE of Au (III) on a 2-aminobenzothiazole-coated Diaion SP 207-column system has been developed. The parameters, including pH of solution, amount of 2-aminobenzothiazole, eluent type, sample volume, and flow rates, were examined. The effects of alkali, alkali earth, and some metals were also studied. The recovery values at optimal conditions and detection limits for Au (III) were found as >95% and 3.8 μg L(-1), respectively. The factor of preconcentration was 250. The RSD value was determination of gold was applied to water, mine, soil, and anodic slime samples. PMID:26964845

  8. A new preconcentration and separation method for flame atomic absorption spectrometric determinations of some trace metal ions on a diaion HP-20 column

    A preconcentration/separation method for determination of Cr(3), Cd(2), Bi(3) and Co(2) has been proposed. The analytes were adsorbed on a column filled Diaion HP-20 resin as metal-8-hydroxiquinoline complexes and desorbed from the column by using 10 ml of 1M HNO3 in acetone. The influences of some analytical parameters such as pH, amounts of oxine, type of eluent etc on the recoveries of chromium, cadmium, bismuth and cobalt were discussed. Effects of the various alkaline salts on the recoveries of the investigated ions were also examined. The method was applied for the determination of Cr(3), Cd(2), Bi(3), and Co(2) contents of table salt samples, some chemical grade alkaline salts produced in Turkey and a stream sediment standard reference material sample (GBW 07309) with satisfactory results (recoveries > 95%, relative standard deviations < 9%). The limit of detection for analyte ions (3s, N=20) was between 23-305 ng/g

  9. Determination of actinides by alpha spectrometric methods

    attributes of mass activities of radionuclides in oyster mushroom's sporocarps compared to their sub-base. We used two methods to separate the monitored radionuclides in a radiochemical analyse. The first of them was an extraction fluid - fluid with Aliquat-336 to separate Pu and TOPO to separate Am. The second method was a proceeding modified by us and utilizing principles of an extraction chromatography with TRU Resin and DGA Resin sorbents made by Eichrom Company. An effectivity and a suitability of both applied methods were monitored following the attributes of radiochemical extractions used in tracer's radionuclides 242Pu a 243Am in this particular type of environmental samples. The reliability of the modified methodology, in accordance to selected criteria for validation of analytical method, was proved by comparison of both above mentioned methods. material delivered from IAEA, which presented a soil sample with code identification Soil IAEA-375. The obtained values of mass activities of 239+240Pu, 239Pu and 241Am used in reference material, demonstrated a conformity with IAEA values, whereby we fulfilled one of the significant conditions of validate process. At the end of this thesis we applied the modified method of extraction chromatography with UTEVA Resin sorbent to define mass activities of uranium on soil and water samples where we monitored attributes of radiochemical extractions of 232U tracer's radionuclide as the criteria of utilizability. The reliability of our modified method was verified by participation in international interlaboratory comparative proficiency tests and our results were in accordance with results of the reference laboratory. It means also a fulfilment of notable standard of the validate process. The results of all realized experimentations of radionuclides separation whether by extraction fluid - fluid or by extraction chromatography were determined by alpha-spectrometric measurements. (author)

  10. Flame atomic absorption spectrometric (FAAS) determination of copper, iron and zinc in food samples after solid-phase extraction on Schiff base-modified duolite XAD 761

    The present study involves the development of solid-phase extraction (SPE) procedure for the preconcentration of trace amounts of copper (Cu2+), iron (Fe3+) and zinc (Zn2+) ions on duolite XAD 761 modified by bis(2-hydroxyacetophenone)-2,2-dimethyl-1,3-propanediimine(BHAPDMPDI). The complexation between the metal ions and the proposed ligand was investigated potentiometrically. The metal ions retained on the sorbent were quantitatively determined via complexation with BHAPDMPDI. The complexed metal ions were efficiently eluted using 6 mL of 4 mol L−1 nitric acid in acetone. The influences of the analytical parameters, including pH, amounts of the ligand and the solid phase, eluent conditions and sample volume, on the recoveries of the metal ions were optimized. Using the optimized parameters, the linear response of the SPE method for Cu2+, Zn2+ and Fe3+ ions were in the ranges of 0.01–0.34, 0.01–0.28 and 0.02–0.31 μg mL−1, respectively, and the detection limits for Cu2+, Zn2+ and Fe3+ ions were 1.8, 1.6 and 2.4 μg mL−1, respectively. The proposed method exhibits a preconcentration factor of 208 for all of the ions studied and an enhancement factor for Cu2+, Fe3+ and Zn2+ ions of 34, 28 and 38, respectively. The presented results demonstrate the successful application of the proposed method for the determination of these metal ions in some real samples with high recoveries (> 95%) and reasonable relative standard deviation (RDS < 5%). Highlights: ► Highly efficient adsorbent for dye removal was synthesized. ► The sorbent was fully characterized. ► The proposed method has a potential of a waste water treatment alternative. ► Excellent properties of the sorbent have been illustrated in detail

  11. Accuracy of X-ray fluorescence spectrometric determination of Rb and Sr concentrations in rock samples

    It is shown that application of the Compton scattering for matrix correction in the X-ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide concentrations at a relative accuracy level of 1%. The empirical method applies to rock samples showing differences in mass absorption up to a factor of two. The accuracy of the method has been tested by analysis of 57 samples analysed for Rb and Sr by mass spectrometric isotope dilution. In addition a few of the U.S. Geological Survey reference rock powders, showing significantly different mass absorption, were analysed for Rb and Sr. It is demonstrated that the mica effect, if significant, is smaller than 1% relative. There is no advantage in the use of the LiF(220) analysing crystal as a substitute for the LiF(200). The method appears to be insensitive to the pellet thickness. (author)

  12. Determination of trace metal ions via on-line separation and preconcentration by means of chelating Sepharose beads in a sequential injection lab-on-valve (SI-LOV) system coupled to electrothermal atomic absorption spectrometric detection

    Long, Xiangbao; Hansen, Elo Harald; Miró, Manuel

    2005-01-01

    The analytical performance of an on-line sequential injection lab-on-valve (SI-LOV) system using chelating Sepharose beads as sorbent material for the determination of ultra trace levels of Cd(II), Pb(II) and Ni(II) by electrothermal atomic absorption spectrometry (ETAAS) is described and discussed...

  13. Photometric and emission-spectrometric determination of boron in steels

    A method for the photometric determination of boron in unalloyed and alloyed steels is described, in which Curcumine is used as reagent. A separation of boron is not necessary. Limit of detection: 0.0003% B. The decomposition of boron nitride in the steel is achieved by heating the whole sample in fuming sulphuric acid/phosphoric acid. For the emission spectrometric investigation of solid steel samples and for the spectrochemical analysis of solutions with plasma excitation working parameters are given and possibilities of interferences are demonstrated. (orig.)

  14. Photometric and emission-spectrometric determination of boron in steels

    Thierig, D.

    1982-01-01

    A method for the photometric determination of boron in unalloyed and alloyed steels is described, in which Curcumine is used as reagent. A separation of boron is not necessary. Limit of detection: 0.0003% B. The decomposition of boron nitride in the steel is achieved by heating the whole sample in fuming sulphuric acid/phosphoric acid. For the emission spectrometric investigation of solid steel samples and for the spectrochemical analysis of solutions with plasma excitation working parameters are given and possibilities of interferences are demonstrated.

  15. 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

  16. Flame atomic absorption spectrometric determination of zinc, nickel, iron and lead in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their bis (2-hydroxyacetophenone)-1, 3-propanediimine chelates

    A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L-1 HNO3. The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

  17. Solid phase extraction of cadmium on 2-mercaptobenzothiazole loaded on sulfur powder in the medium of ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate and cold vapor generation-atomic absorption spectrometric determination

    A novel solid phase extractor for preconcentration of cadmium at ng L-1 levels has been developed. Cadmium ions were retained on a column packed with sulfur powder modified with 2-mercaptobenzothiazole (2-MBT) in the medium of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]+PF6-) ionic liquid. The presence of ionic liquid during modification of sulfur enhanced the retention of cadmium ions on the column. The retained cadmium ions were eluted with 2 mol L-1 solution of HCl and measured by cold vapor generation-atomic absorption spectrometry (CVG-AAS). By using reaction cell-gas liquid separator (RC-GLS), gaseous cadmium vapors were produced and reached the atomic absorption spectrometer, instantaneously. The influence of different variables on both processes of solid phase extraction and CVG-AAS determination of cadmium ions was investigated. The calibration curve was linear in the range of 10-200 ng L-1of cadmium in the initial solution with r = 0.9992 (n = 8) under optimum conditions. The limit of detection based on three times the standard deviation of the blank (3Sb, n = 10) was 4.6 ng L-1. The relative standard deviation (R.S.D.) of 25 and 150 ng L-1 of cadmium was 4.1 and 2.2% (n = 8), respectively. The procedure was validated by the analysis of a certified reference material (DORM-3), water and fish samples.

  18. Determination of iodine to compliment mass spectrometric measurements

    The dose of iodine-129 to facility personnel and the general public as a result of past, present, and future activities at DOE sites is of continuing interest, WINCO received about 160 samples annually in a variety of natural matrices, including snow, milk, thyroid tissue, and sagebrush, in which iodine-129 is determined in order to evaluate this dose, Currently, total iodine and the isotopic ratio of iodine-127 to iodine-129 are determined by mass spectrometry. These two measurements determine the concentration of iodine-129 in each sample, These measurements require at least 16 h of mass spectrometer operator time for each sample. A variety of methods are available which concentrate and determine small quantities of iodine. Although useful, these approaches would increase both time and cost. The objective of this effort was to determine total iodine by an alternative method in order to decrease the load on mass spectrometry by 25 to 50%. The preparation of each sample for mass spectrometric analysis involves a common step--collection of iodide on an ion exchange bed. This was the focal point of the effort since the results would be applicable to all samples

  19. Flame atomic absorption spectrometric determination of trace amounts of Pb(II) and Cr(III) in biological, food and environmental samples after preconcentration by modified nano-alumina

    A new solid-phase extraction sorbent was used for the preconcentration of Pb(II) and Cr(III) ions prior to their determination by flame atomic absorption spectrometry. It was prepared by immobilization of 2,4-dinitrophenylhydrazine on nano-alumina coated with sodium dodecyl sulfate. The sorbent was characterized by scanning electron microscopy, N2 adsorption and Fourier transform infrared spectrometry, and used for preconcentration and separation of Pb(II) and Cr(III) from aqueous solutions. The ions on the sorbent were eluted with a mixture of nitric acid and methanol. The effects of sample pH, flow rates of samples and eluent, type of eluent, breakthrough volume and potentially interfering ions were studied. Linearity is maintained between 1.2 and 350 μg L-1 of Pb(II), and between 2.4 and 520 μg L-1 of Cr(III) for an 800-mL sample. The detection limit (3 s, N=10) for Pb(II) and Cr(III) ions is 0.43 and 0.55 μg L-1, respectively, and the maximum preconcentration factor is 267. The method was successfully applied to the evaluation of these trace and toxic metals in various water, food, industrial effluent and urine samples. (author)

  20. Electrothermal atomic absorption spectrometric determination of vanadium in extracts of soil and sewage sludge certified reference materials after fractionation by means of the Communities Bureau of Reference modified sequential extraction procedure

    A modified three-step sequential extraction procedure proposed by the Commission of European Communities Bureau of Reference (BCR) was applied to certified reference materials of three different soil groups (rendzina, luvisol, cambisol) and sewage sludge of different composition originating from a municipal water treatment plant in order to assess potential mobility and the distribution of vanadium in the resulting fractions. Analysis of the extracts was carried out by electrothermal atomic absorption spectrometry with Zeeman background correction using transversely heated graphite atomizers. Extracts showed significant matrix interferences which were overcome by the standard addition technique. The original soil and sludge certified reference materials (CRMs) and the extraction residue from the sequential extraction were decomposed by a mixture of HNO3-HClO4-HF in an open system. The content of V determined after decomposition of the samples was in very good agreement with the certified total values. The accuracy of the sequential extraction procedure was checked by comparing the sum of the vanadium contents in the three fractions and in the extraction residue with the certified total content of V. The amounts of vanadium leached were in good correlation with the certified total contents of V in the CRMs of soils and sewage sludge. In the soils examined, vanadium was present almost entirely in the mineral lattice, while in the sewage sludge samples 9-14% was found in the oxidizable and almost 25% in the reducible fractions. The recovery ranged from 93-106% and the precision (RSD) was below 10%

  1. Method of double tracer addition for determining uranium in geological samples by mass spectrometric isotope dilution

    The present work shows the experimental details on the uranium determination in materials by mass spectrometric isotope dilution technique with double tracer (233U + 235U). The mass discrimination phenomenon effect is studied. The uranium concentration values obtained by mass spectrometric isotope dilution technique with double tracer are compared with other techniques. The influence of the sampling in the accurate determination of uranium in the rock sample is discussed. (author)

  2. Uranium determination using atomic spectrometric techniques: An overview

    This review focuses on the determination of uranium using spectroanalytical techniques that are aimed at total determination such as flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma optical emission spectrometry (ICP-OES); and inductively coupled plasma mass spectrometry (ICP-MS) that also enables the determination of uranium isotopes. The advantages and shortcomings related to interferences, precision, accuracy, sample type and equipment employed in the analysis are taken into account, as well as the complexity and costs (i.e., acquisition, operation and maintenance) associated with each of the techniques. Strategies to improve their performance that employ separation and/or preconcentration steps are considered, with an emphasis given to solid-phase extraction because of its advantages compared to other preconcentration procedures.

  3. Highly selective micro-sequential injection lab-on-valve (μSI-LOV) method for determination of ultra trace concentrations of nickel in saline matrices using detection by electrothermal atomic absorption spectrometr

    Long, Xiangbao; Miró, Manuel; Jensen, Rikard;

    2006-01-01

    electrothermal atomic absorption spectrometry (ETAAS). Based on the dimethylglyoxime (DMG) gravimetric procedure used for nickel analysis, the sample, as contained in pH 9.0 buffer, is, after on-line merging with the chelating reagent, transported to a reaction coil attached to one of the external ports of the...

  4. Radioisotope spectrometric method to determine diffusion coefficients in metals and alloys

    A brief description of the spectrometric installation to study diffusion in metals using #betta#-decay radio-isotopes is presented. Diffusion coefficients of nickel in 70% Co-5% Fe-15% Si-10% B amorphous alloy are determined according to #betta#-radiation absorption in diffusion zone. Plate samples of 10x10 mm size and about 300 μm in thickness are used. Diffusion annealing is conducted during 100 hrs. The calculation of the diffusion coefficients has been carried out by the formula I/I0= esup(μsup(2)Dtau)erfc μ √ Dtau, where I0, I is an initial and a final radiation intensity; μ- an absorption coefficient of 63Ni #betta#-ray in the given material (at calculation μ=1.3x106 m-1 was taken); tau- duration of diffusion annealing; D- diffusion coefficient at the designed temperature. The value of the diffusion coefficient of nickel in 70% Co-5% Fe-15% S-10% B amorphous alloy at the temperature of 200 deg C is turned out to be equal to 4x10-21 m2/s. It should be noted that the self-diffusion coefficient of cobalt in Co-Fe alloy, found by extrapolation from high-temperature region, is equal to 10-35 m2/s, i.e. in 14 orders lower than that of the same basis in amorphous alloy

  5. Spectrometric methods for the determination of chlorine in crude oil and petroleum derivatives — A review

    Chlorine determination in crude oil is made in order to guarantee that the oil does not contain levels of this element that might cause damages in the oil processing equipment. In petroleum products, the determination of chlorine is made, for instance, to evaluate if there are proper concentrations of organochloride compounds, which are used as additives. Such determinations are currently performed following official guidelines from the ASTM International and from the United States Environmental Protection Agency as well as protocols indicated by the Universal Oil Products. X-ray fluorescence spectroscopy plays an important role in many of these official methods. In contrast, other spectrometric methods based on optical and mass detection are plagued by limitations related to both the fundamental characteristics of non-metals and to the complex sample matrices, which reflects in the small number of articles devoted to these applications. In this review, the current status of the spectrometric methods, especially the role played by X-ray fluorescence spectrometry, is evaluated in terms of the determination of chlorine in crude oil and petroleum derivatives. Comparison of the performance of the methods, limitations and potential new approaches to ensure proper spectrometric determinations of chlorine is indicated. - Highlights: • Critical evaluation of spectrometric methods for chlorine in petroleum products. • Reviews on element determination in petroleum have not address the case of chlorine. • Peculiarities of the spectrometric determination of Cl in petroleum are discussed. • The spectrometric approaches are detailed and compared to the official methods. • New trends in chlorine determination in petroleum products are indicated

  6. Spectrometric methods for the determination of chlorine in crude oil and petroleum derivatives — A review

    Doyle, Adriana [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marquês de São Vicente 225, Gávea, Rio de Janeiro, RJ 22451-900 (Brazil); Saavedra, Alvaro; Tristão, Maria Luiza B.; Mendes, Luiz A.N. [Leopoldo Américo Miguez de Mello Research Center — Petrobras (CENPES), Cidade Universitária, Quadra 7, Ilha do Fundão, Rio de Janeiro 21949-900 (Brazil); Aucélio, Ricardo Q., E-mail: aucelior@puc-rio.br [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marquês de São Vicente 225, Gávea, Rio de Janeiro, RJ 22451-900 (Brazil)

    2013-08-01

    Chlorine determination in crude oil is made in order to guarantee that the oil does not contain levels of this element that might cause damages in the oil processing equipment. In petroleum products, the determination of chlorine is made, for instance, to evaluate if there are proper concentrations of organochloride compounds, which are used as additives. Such determinations are currently performed following official guidelines from the ASTM International and from the United States Environmental Protection Agency as well as protocols indicated by the Universal Oil Products. X-ray fluorescence spectroscopy plays an important role in many of these official methods. In contrast, other spectrometric methods based on optical and mass detection are plagued by limitations related to both the fundamental characteristics of non-metals and to the complex sample matrices, which reflects in the small number of articles devoted to these applications. In this review, the current status of the spectrometric methods, especially the role played by X-ray fluorescence spectrometry, is evaluated in terms of the determination of chlorine in crude oil and petroleum derivatives. Comparison of the performance of the methods, limitations and potential new approaches to ensure proper spectrometric determinations of chlorine is indicated. - Highlights: • Critical evaluation of spectrometric methods for chlorine in petroleum products. • Reviews on element determination in petroleum have not address the case of chlorine. • Peculiarities of the spectrometric determination of Cl in petroleum are discussed. • The spectrometric approaches are detailed and compared to the official methods. • New trends in chlorine determination in petroleum products are indicated.

  7. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    Highlights: ► The use of CNTs as sorbent for metal species in solid phase extraction has been described. ► Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. ► Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes – due to their high adsorption and desorption capacities – have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  8. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    Herrero Latorre, C., E-mail: carlos.herrero@usc.es [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain); Alvarez Mendez, J.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.M. [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The use of CNTs as sorbent for metal species in solid phase extraction has been described. Black-Right-Pointing-Pointer Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. Black-Right-Pointing-Pointer Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes - due to their high adsorption and desorption capacities - have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  9. Mass spectrometric determination of early and advanced glycation in biology.

    Rabbani, Naila; Ashour, Amal; Thornalley, Paul J

    2016-08-01

    Protein glycation in biological systems occurs predominantly on lysine, arginine and N-terminal residues of proteins. Major quantitative glycation adducts are found at mean extents of modification of 1-5 mol percent of proteins. These are glucose-derived fructosamine on lysine and N-terminal residues of proteins, methylglyoxal-derived hydroimidazolone on arginine residues and N(ε)-carboxymethyl-lysine residues mainly formed by the oxidative degradation of fructosamine. Total glycation adducts of different types are quantified by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring mode. Metabolism of glycated proteins is followed by LC-MS/MS of glycation free adducts as minor components of the amino acid metabolome. Glycated proteins and sites of modification within them - amino acid residues modified by the glycating agent moiety - are identified and quantified by label-free and stable isotope labelling with amino acids in cell culture (SILAC) high resolution mass spectrometry. Sites of glycation by glucose and methylglyoxal in selected proteins are listed. Key issues in applying proteomics techniques to analysis of glycated proteins are: (i) avoiding compromise of analysis by formation, loss and relocation of glycation adducts in pre-analytic processing; (ii) specificity of immunoaffinity enrichment procedures, (iii) maximizing protein sequence coverage in mass spectrometric analysis for detection of glycation sites, and (iv) development of bioinformatics tools for prediction of protein glycation sites. Protein glycation studies have important applications in biology, ageing and translational medicine - particularly on studies of obesity, diabetes, cardiovascular disease, renal failure, neurological disorders and cancer. Mass spectrometric analysis of glycated proteins has yet to find widespread use clinically. Future use in health screening, disease diagnosis and therapeutic monitoring, and

  10. 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

  11. X-ray spectrometric determination of thorium in bone and other biological materials

    An x-ray spectrometric method has been developed for the determination of thorium in bone and other biological materials. The limit of detection at the 95% confidence level is 20 ng. This corresponds to a concentration of 2 ppb in a 10-g sample of bone ash

  12. Atomic Absorption Spectrometric Method for Estimation of Diclofenac sodium and Mefenamic acid in Pharmaceutical Formulations

    Sunil Jawla

    2010-01-01

    Full Text Available Diclofenac sodium and Mefenamic acid have been quantified in tablet dosage form by atomic absorption spectrometry (AAS. These methods are based on formation of the metal complexes of Diclofenac sodium and Mefenamic acid with cupric chloride and cobaltous chloride. The first method is based on reaction of both the drugs with cupric chloride to give light blue colored metal complexes, which are then extracted with dichloromethane and digested with 0.1 M nitric acid. Both the drugs are indirectly estimated via determination of copper content in the formed complexes by AAS. The second method is based on the formation of pink colored complexes of both the drugs with cobaltous chloride. These metal complexes are extracted with dichloromethane and estimated via determination of cobalt content in the formed complexes after digestion with 0.1 M nitric acid by AAS.

  13. The accuracy of X-ray fluorescence spectrometric determination of Rb and Sr contents in rock sample

    It is shown that application of the Compton scattering method in the X-ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide element contents at an accuracy level +- 1 %

  14. Continuous flow hydride generation-atomic fluorescence spectrometric determination and speciation of arsenic in wine

    Methods for the atomic fluorescence spectrometric (AFS) determination of total arsenic and arsenic species in wines based on continuous flow hydride generation (HG) with atomization in miniature diffusion flame (MDF) are described. For hydride-forming arsenic, L-cysteine is used as reagent for pre-reduction and complexation of arsenite, arsenate, monomethylarsonate and dimethylarsinate. Concentrations of hydrochloric acid and tetrahydroborate are optimized in order to minimize interference by ethanol. Procedure permits determination of the sum of these four species in 5-10-fold diluted samples with limit of detection (LOD) 0.3 and 0.6 μg l-1 As in white and red wines, respectively, with precision between 2% and 8% RSD at As levels within 0.5-10 μg l-1. Selective arsine generation from different reaction media is used for non-chromatographic determination of arsenic species in wines: citrate buffer at pH 5.1 for As(III); 0.2 mol l-1 acetic acid for arsenite + dimethylarsinate (DMA); 8 mol l-1 HCl for total inorganic arsenic [As(III) + As(V)]; and monomethylarsonate (MMA) calculated by difference. Calibration with aqueous and ethanol-matched standard solutions of As(III) is used for 10- and 5-fold diluted samples, respectively. The LODs are 0.4 μg l-1 for As(III) and 0.3 μg l-1 for the other three As species and precision is within 4-8% RSDs. Arsenic species in wine were also determined by coupling of ion chromatographic separation on an anion exchange column and HG-flame AFS detection. Methods were validated by means of recovery studies and comparative analyses by HG-AFS and electrothermal atomic absorption spectrometry after microwave digestion. The LODs were 0.12, 0.27, 0.15 and 0.13 μg l-1 (as As) and RSDs were 2-6%, 5-9%, 3-7% and 2-5% for As(III), As(V), MMA and DMA arsenic species, respectively. Bottled red and white wines from Bulgaria, Republic of Macedonia and Italy were analyzed by non-chromatographic and chromatographic procedures and the As

  15. Mass spectrometric methods for studying nutrient mineral and trace element absorption and metabolism in humans using stable isotopes: a review

    Mass spectrometric methods for determining stable isotopes of nutrient minerals and trace elements in human metabolic studies are described and discussed. The advantages and disadvantages of the techniques of electron ionization, fast atom bombardment, thermal ionization, and inductively coupled plasma and gas chromatography mass spectrometry are evaluated with reference to their accuracy, precision, sensitivity, and convenience, and the demands of human nutrition research. Examples of specific applications are described and the significance of current developments in mass spectrometry are discussed with reference to present and probable future research needs. (Author)

  16. Extraction-mass spectrometric determination of platinum metals in materials of complex composition

    A method is developed for the extraction mass-spectrometric determination of platinum metals, including ruthenium. The loWer limit of detectable contents is 1.6x10-6 mass.% (a coefficient of concentration is 50). The relative standard deviation is 0.19-0.38. Relative sensitivity coefficients determined experimentally with the aid of reference samples for platinum metals enable the systematic errors of analysis results to be taken into account. The method is most advisably used for the simultaneous determination of platinum metals in complex objects (minerals, rocks, etc.)

  17. Determination of Mass Spectrometric Sensitivity of Different Metalloporphyrin Esters Relative to Porphyrin Ester

    Larsen, Elfinn; Egsgaard, Helge; Møller, J.; With, T. K.

    1977-01-01

    Quantitative determination of metalloporphyrin contamination in preparations of biologically important porphyrins was achieved mass spectrometrically by application of the integrated ion current technique. For this purpose, the relative molecular ion sensitivities of the contaminating metal compl...... complexes were determined from the ratios of the integrated molecular ion currents of a series of calibration samples containing a porphyrin ester and one of its metal complexes in known molar ratio. Complexes formed with divalent ions of Cu, Zn, Fe, Co and Ni of copro- as well as uro...

  18. 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.

  19. 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.

  20. Determination of trace quantities of uranium in rocks mass spectrometric isotope dilution technique

    A detailed experimental investigation on the thermionic emission of uranium deposited on a single flat type rhenium filament has been carried out. The study was aimed at determining the influence of various forms of deposition on the emission sensitivity and thermal stability of U+ , UO+ and UO2+ ions. Based on these investigations, a technique, involving an addition of a small quantity of colloidal suspension of graphite on top of the uranyl nitrate sample deposited, was chosen because of its higher, emission sensitivity for uranium metal ions. The experimental parameters of the technique were optimised and the technique was employed in the determination of trace quantities of uranium in rock samples using mass spectrometric isotope dilution method. For the mass spectrometric isotope dilution analysis National Bureau of Standards uranium isotopic standard NBS-U 970 was employed as a tracer, where as the mass discrimination effect in the uranium isotope analysis was corrected using the uranium isotopic standard NBS-U500. Uranium was determined in each of the seven granite samples from Wyoming, USA and two USGS standard rocks. The precision of the analysis was found to be ±1% . The uranium values obtained on the rock samples were compared with the analyses of other investigators. Influence of the sample splitting on the uranium analysis was discussed in the light of the analytical results obtained.(author)

  1. Mass-spectrometric determination of trace elements in aqueous media without preconcentration

    Foss, G. O.

    1981-10-01

    Feasibility of using a low pressure glow discharge as an ion source for the mass spectrometric determination of trace elements in aqueous media was investigated. A cryogenically cooled hollow cathode ion source was developed to analyze aqueous samples without external preconcentration. Aqueous solutions containing seventy elements were analyzed and the detection limits, sensitivity factors, and linear regression correlation coefficients were determined. A standard test solution of trace elements in water was analyzed and the concentrations of trace elements were calculated using the sensitivity factors determined previously. The results compared favorably within the error limits predicted by the semiquantitative survey methods used. Tap water and natural lake water samples were examined and minimal interference effects due to organic compounds and biological compounds were noted. A research ion optical system (RIOS) was developed as a flexible mass analyzer for the development of new ion sources. The RIOS is a double focussing mass analyzer designed utilizing the Mattauch-Herzog geometry with externally adjustable slit assemblies.

  2. A simple method for determination of formaldehyde in seafood sample using spectrometric detection

    Complete text of publication follows. A simple method for determination of formaldehyde using spectrometric detection was developed. The reaction was based on the oxidation of methylene blue with hydrogen peroxide in acidic media. The decreased in absorbance of the reaction mixture was measured at 664 nm. The optimum reaction conditions were 1 x 10-6 M methylene blue, 0.01 M sulfuric acid and 0.02 M hydrogen peroxide. The linearity was 0-20 mg/l with the limit of determination 1.60 μg/g of sample. Extraction of formaldehyde in seafood samples were investigated by ultrasonic method. The percentage recovery in spiking sample was 98% with 30 min ultrasonic extraction. This proposed method was applied to determination of formaldehyde in seafood samples. The researcher gratefully acknowledge the support from Center of Excellence for Innovation in Chemistry (PERCH-CIC), Commission on Higher Education, Ministry of Education.

  3. Particle size independent spectrometric determination of wear metals in aircraft lubricating oils

    A method for the particle size independent determination of Ni, Fe, Mg, Cu, Al, Sn, Mo, and Ti in synthetic ester lubricating oils by spectrometric analysis is presented. Partial dissolution of Cr, Si, Pb, and Ag also occurs. Used ester lubricating oils as well as samples prepared with -325 mesh (44 μm) or -200 mesh (74 μm) metal powders were reacted with a small amount of hydrofluoric acid and aqua regia at 650C for 45 min with ultrasonic agitation. The reacted mixture was then diluted with a methyl isobutyl ketone and isopropyl alcohol mixture and analyzed spectrometrically. The recoveries for metal powder suspensions of Ni, Fe, Mg, Cu, Al, Sn, Mo, and Ti ranged from 97 to 103% and the relative standard deviation ranged from 4 to 10%. In addition to the metal powder suspensions, over 200 aircraft oil samples were analyzed. The method is much faster and more convenient than previously reported particle size independent methods using ashing techniques

  4. Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples

    Hou, Xiaolin; Roos, Per

    2008-01-01

    The radiometric methods, alpha (alpha)-, beta (beta)-, gamma (gamma)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. These methods are critically compared for the determination of long-lived radionuclides important for rad...

  5. Determination of Mass Spectrometric Sensitivity of Different Metalloporphyrin Esters Relative to Porphyrin Ester

    Larsen, Elfinn; Egsgaard, Helge; Møller, J.;

    1977-01-01

    Quantitative determination of metalloporphyrin contamination in preparations of biologically important porphyrins was achieved mass spectrometrically by application of the integrated ion current technique. For this purpose, the relative molecular ion sensitivities of the contaminating metal...... complexes were determined from the ratios of the integrated molecular ion currents of a series of calibration samples containing a porphyrin ester and one of its metal complexes in known molar ratio. Complexes formed with divalent ions of Cu, Zn, Fe, Co and Ni of copro- as well as uro......-prophyrin permethylester were all found to have the same molecular ion sensitivities as their metal-free porphyrin ester. The relative metalloporphyrin ester content in a sample of porphyrin ester was thus obtained directly as the integrated ion current ratios of the normalized molecular ions. The preparation of...

  6. Quantitative analysis of sodium di-uranate for Al, Ca, Fe, Mg, Mn, Na by flame-atomic absorption spectrometric method

    Nuclear Fuel Complex (NFC) receives Sodium Di-Uranate (SDU) from Uranium Corporation of India Limited (UCIL) for producing sinterable UO2 pellets for manufacturing fuel sub assemblies. Several impurities present in ore find their way into SDU during its conversion. Stringent specification have been laid down by the reactor designs for achieving the optimum performance of the fuel and several impurity element like Al, Ca, Fe, Mg, Mn, Na among others affects severely performance of UO2 fuel. Most of the impurity including the above mentioned elements are generally analysed by ICP-OES method. However, determination of Al, Ca, Fe, Mg, Mn and Na by ICP-OES requires lot of dilution as they are present at high levels in SDU. Apart from introducing dilution error, dilution process is very tedious and time consuming work and not a preferred choice in an industrial lab like control lab where large analytical load exists and time bound analysis is a requirement. To avoid these difficulties a simple and reliable Flame Atomic absorption spectrometric technique has been developed for regular analysis. Present method involves dissolution of SDU sample in Conc. HNO3 and after the complete dissolution the sample solution has been evaporated to near dryness on a hot plate. Subsequently sample solution has been brought into 4N HNO3 medium

  7. Atomic-spectrometric determination of lithium, sodium, potassium and strontium in high-pure scandium

    Determination of lithium, sodium and potassium in strontium by flame photometry with atomic-absorption spectrophotometer is described. Scandium effect on value of Li, K. Na analytical signal in flame is studied. It is shown, that the base understates analytical signals. Determination of strontium by flame photometry is impossible. Determination of strontium (1x10-13 kg/ml) by atomic-absorption method with electrothermal atomization is possible

  8. Optical Path Length Calibration: A Standard Approach for Use in Absorption Cell-Based IR-Spectrometric Gas Analysis

    Javis Anyangwe Nwaboh; Oliver Witzel; Andrea Pogány; Olav Werhahn; Volker Ebert

    2014-01-01

    We employed a comparison method to determine the optical path length of gas cells which can be used in spectroscopic setup based on laser absorption spectroscopy or FTIR. The method is based on absorption spectroscopy itself. A reference gas cell, whose length is a priori known and desirably traceable to the international system of units (SI), and a gas mixture are used to calibrate the path length of a cell under test. By comparing spectra derived from pressure-dependent measurements on the ...

  9. Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

    Suh, M. Y.; Han, S. H.; Kim, J. G.; Park, Y. J.; Kim, W. H

    2005-12-15

    This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here.

  10. Separation Techniques for Uranium and Plutonium at Trace Levels for the Thermal Ionization Mass Spectrometric Determination

    This report describes the state of the art and the progress of the chemical separation and purification techniques required for the thermal ionization mass spectrometric determination of uranium and plutonium in environmental samples at trace or ultratrace levels. Various techniques, such as precipitation, solvent extraction, extraction chromatography, and ion exchange chromatography, for separation of uranium and plutonium were evaluated. Sample preparation methods and dissolution techniques for environmental samples were also discussed. Especially, both extraction chromatographic and anion exchange chromatographic procedures for uranium and plutonium in environmental samples, such as soil, sediment, plant, seawater, urine, and bone ash were reviewed in detail in order to propose some suitable methods for the separation and purification of uranium and plutonium from the safeguards environmental or swipe samples. A survey of the IAEA strengthened safeguards system, the clean room facility of IAEA's NWAL(Network of Analytical Laboratories), and the analytical techniques for safeguards environmental samples was also discussed here

  11. Liquid chromatography-mass spectrometric determination of rufinamide in low volume plasma samples.

    Gáll, Zsolt; Vancea, Szende; Dogaru, Maria T; Szilágyi, Tibor

    2013-12-01

    Quantification of rufinamide in plasma was achieved using a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method. The chromatographic separation was achieved on a reversed phase column (Zorbax SB-C18 100mm×3mm, 3.5μm) under isocratic conditions. The mobile phase consisted of a mixture of water containing 0.1% formic acid and methanol (50:50, v/v). The mass spectrometric detection of the analyte was in multiple reaction monitoring mode (MRM) using an electrospray positive ionization (ESI positive). The monitored ions were 127m/z derived from 239m/z rufinamide and 108m/z derived from 251m/z the internal standard (lacosamide). Protein precipitation with methanol was applied for sample preparation using only 50μl aliquots. The concentration range was 40-2000ng/ml for rufinamide in plasma. The limit of detection was 1.25ng/ml and the lower limit of quantification was established at 5ng/ml rufinamide concentration. Selectivity and matrix effect was verified using individual human, rat and rabbit plasma samples. Short-term, post-preparative and freeze-thaw stability was also investigated. The proposed method provides accuracy, precision and high-throughput (short runtime 4.5min) for quantitative determination of rufinamide in plasma. This is the first reported liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for analysis of rufinamide from low volume plasma samples. The LC-MS/MS method was validated according to the current official guidelines and can be applied to accurately measure rufinamide level of large number of plasma samples from clinical studies or therapeutic drug monitoring. PMID:24140655

  12. Determination of Lead Content in Phosphate Rock and Concentrate Rock——Flame Atomic Absorption Spectrometric Method%火焰原子吸收光谱法测定磷矿石和精磷矿中的铅含量

    沈治荣; 梁聪; 甘丽; 何红莲

    2011-01-01

    This article describes determination of trace harmful heavy metal-lead element in phosphate rock and concentrate rock with flame atomic absorption spectrometry method.The relative standard deviation of this method is 3.1~14.2%,recovery rate is 90%~104%,the sample detection limit is 0.0008%.The method is accurate,fast,easy,make up for method of determination lead in phosphate rock.It provides effective control method for production of feed additives and fertilizers and so on.%研究了用火焰原子吸收光谱法测定磷矿石或磷精矿中微量的铅的检测方法。此方法的相对标准偏差为3.1%-14.2%,回收率为90%-104%,样品检测下限为0.0008%。

  13. Method Validation for the Gamma-ray Spectrometric Determination of Natural Radioactive Nuclides in NORM Samples - Method Validation for the Gamma-ray Spectrometric Determination of Natural Radionuclides in raw materials and by-products

    It has established the 'Act on safety control of radioactive rays around living environment' in Korea, since 2011, to protect the public from natural occurring radioactive materials (NORM) and their by-products. The increasing concerns regarding the radioactivity of those materials therefore dictate many demands for the radioactive analysis for them. There are several methods to determine the concentration of natural radionuclides, such as 235U, 238U, 226Ra, 232Th, and so on, through a radiochemical analysis using an alpha spectrometer, mass spectrometer and liquid scintillation counter. However, gamma-ray spectroscopy still has an effect on the assessment of radioactive concentration for these nuclides and their progenies. To adapt a gamma spectrometer to the determination of natural radionuclides, the feasibility of their analysis methods should be first verified and validated with respect to accuracy and time and cost constraints. In general, one of the well-known processes in analyzing uranium with a gamma spectrometer is an indirect measurement using the secular equilibrium state with their progenies in a sample. This method, however, demands the time elapsed about 3 weeks to reach the equilibrium state between 226Ra and 222Rn and the sufficient integrity of a sample bottle to prevent the leakage of radon isotopes which is a form of noble gas. The simple and quick method is to directly measure a full energy absorption peak of 186.2 keV from 226Ra without the secular equilibrium state between 226Ra and 222Rn in the common sample bottle. However, this direct measurement also has difficulties about the interference with a full energy absorption peak of 185.7 keV from 235U. In this study, direct measurement with the interference correction technique, which uses several reference peaks for gamma-rays from 235U and 234Th, and indirect measurement, which means the identification of 226Ra indicators such as 214Pb and 214Bi after the secular equilibrium in the NORM

  14. Determination of U and Th content in the zirconium purification process using alpha spectrometric method

    It has been performed determination of U and Th and decay daughter in the zirconium purification process using alpha spectrometric method. U and Th analysis applications as well as decay daughter of zirconium purification process done, from Na2ZrO3 dissolved stage, Na2ZrO3 dissolved with 4 M HCl, dissolving Chloride Zircon Oxide (ZOC) with 6M H2SO4 at 105°C the heating. The purpose of this study is to determine the concentration of U and Th and decay daughter of Na2ZrO3 dissolved process, Na2ZrO3 dissolved with 4 M HCl, dissolving Chlorid Zircon oxide (ZOC) with 6M H2SO4 at 105° C the heating. From the experiments it can be concluded that the Na2ZrO3 solution and ZrOCI2, there is no U and Th nuclides, where as in solution Zr5O8(SO4)2 there are U and Th content. (author)

  15. Determination of ash content of coal using nuclear borehole logging spectrometric gamma-gamma technique

    During the past decade, increasing effort has been given to monitoring coal quality in the search, production and preparation sequence. Considerable research and development has been carried out on nuclear methods for determination of ash in coal. A number of nuclear techniques are now well established for coal analysis. In particular, the spectrometric gamma-gamma technique is based on the existence of a simple correlation between the ash content and the equivalent atomic number of coal. This technique records and uses the count rates of the backscatter spectrum. These count rates describe the changes in spectral shape which are due to ash content variations. This method is presented along with a short review of the physical background. The report includes the simulation of in situ borehole probe readings using a MONTE CARLO tracking program. Simulating the transport through matter of gamma-rays by MONTE CARLO techniques essentially attempts to reproduce the actual statistical nature of the interaction processes. Random numbers are used throughout, along with known nuclear data, to select the parameters which influence a particle's history. Such an approach can deal with complex geometries through which the particles move. Biaising or weightening techniques are applied for variance reduction, so as to minimise the statistical errors. The basic features of biaising as well as the description of the program are given. A semi-theoretical approach is discussed for the determination of ash content of coal seam using the simulated spectrum

  16. Determination of fission cross-section and absolute fission yields using track-cum gamma-ray spectrometric technique

    The fission cross-section of 233Pa(2nth, f) using fission track technique has been determined for the first time using thermal neutron flux of the reactor APSARA. This is important from the point of view of advance heavy water reactor (AHWR), which is to be described. On the other hand, the yields of fission products in the fast neutron induced fission of minor actinides are important from the point accelerator driven sub critical system (ADSS). In view of that, absolute yields of fission products in the fast neutron induced fission of 238U, 237Np, 238,240Pu, 243Am and 244Cm have been determined using the fission track-cum gamma-ray spectrometric technique. The total number of fission occurring in the target was estimated by track technique, whereas the activities of the fission products have been determined using gamma-ray spectrometric technique. Detailed procedure and its importance are to be discussed. (author)

  17. Nasal absorption studies of granisetron in rats using a validated high-performance liquid chromatographic method with mass spectrometric detection.

    Woo, Jong Soo

    2007-06-01

    Granisetron is a selective 5-HT3 receptor antagonist that is used therapeutically for the prevention of vomiting and nausea associated with emetogenic cancer chemotherapy. Although forms of the drug are commercially available for intravenous and oral dosage, there is a need for intranasal delivery formulations in specific patient populations in which the use of these dosage forms may be unfeasible and/or inconvenient. A rapid and specific high-performance liq uid chromatography method with mass spectrometric detection (LC-MS) was developed and validated for the analysis of granisetron in plasma after nasal administration in rats. Granisetron was separated in a reverse-phase C-18 column without interference from other components of plasma. This method involves a rapid assay for the determination of granisetron in a small volume of plasma with a run time of 12 min using ondansetron as an internal standard. Data were acquired in the electrospray ionization (ESI) mode with positive ion detection and application of single ion recording (SIR). Granisetron and ondansetron were detected at m/z values of 313.2 and 294.2, respectively. The method described was found to be suitable for the analysis of all samples collected during preclinical pharmacokinetic investigations of granisetron in rats after nasal administration. To date, the first pharmacokinetic study after intranasal administration of granisetron was performed and some pharmacokinetic parameters were presented in this paper. Granisetron was found to be well absorbed through nasal route and the bioavailability of this drug following nasal administration was comparable with that of intravenous administration. PMID:17679558

  18. 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...

  19. Column solid phase extraction and flame atomic absorption spectrometric determination of manganese(II) and iron(III) ions in water, food and biological samples using 3-(1-methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid on synthesized graphene oxide.

    Pourjavid, Mohammad Reza; Sehat, Ali Akbari; Arabieh, Masoud; Yousefi, Seyed Reza; Hosseini, Majid Haji; Rezaee, Mohammad

    2014-02-01

    A modified, selective, highly sensitive and accurate procedure for the determination of trace amounts of manganese and iron ions is established in the presented work. 3-(1-Methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid (MPPC) and graphene oxide (GO) were used in a glass column as chelating reagent and as adsorbent respectively prior to their determination by flame atomic absorption spectrometry. The adsorption mechanism of titled metals complexes on GO was investigated by using computational chemistry approach based on PM6 semi-empirical potential energy surface (PES). The effect of some parameters including pH, flow rate and volume of sample and type, volume and concentration of eluent, as well as the adsorption capacity of matrix ions on the recovery of Mn(II) and Fe(III) was investigated. The limit of detection was 145 and 162 ng L(-1) for Mn(II) and Fe(III), respectively. Calibration was linear over the range of 0.31-355 μg L(-1) for Mn(II) and 0.34-380 μg L(-1) for Fe(III) ions. The method was successfully applied for the determination of understudied ions in water, food and biological samples. PMID:24411390

  20. 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 ...

  1. Determination of ractopamine in pig hair using liquid chromatography with tandem mass spectrometric detection.

    Wu, Junlin; Liu, Xiaoyun; Peng, Yunping

    2014-01-01

    A quantitative analytical procedure for the determination of ractopamine in pig hair has been developed and validated. The hair samples were washed and incubated at 75°C with isoxuprine and hair extraction buffer. The drug present was quantified using mixed solid-phase extraction and liquid chromatography with tandem mass spectrometric detection. The limit of quantization (LOQ) was 10pg/mg and the intra-day precision at 25pg/mg and 750pg/mg was 0.49% and 2.8% respectively. Inter-day precision was 0.88% and 3.52% at the same concentrations. The hair extraction percentage recovery at 25pg/mg and 50ng/mL was 99.47% and 103.83% respectively. The extraction percentage recovery at 25pg/mg and 50ng/mg was 93.52% and 100.26% respectively. Our results showed that ractopamine residues persist in hair in 24days of withdrawal and also showed the possibility to test ractopamine from pig hair samples. PMID:24548851

  2. Column solid phase extraction and flame atomic absorption spectrometric determination of manganese(II) and iron(III) ions in water, food and biological samples using 3-(1-methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid on synthesized graphene oxide

    Pourjavid, Mohammad Reza, E-mail: pourjavid@gmail.com [NFCRS, Nuclear Science and Technology Research Institute, P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of); Sehat, Ali Akbari [Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Arabieh, Masoud; Yousefi, Seyed Reza; Hosseini, Majid Haji; Rezaee, Mohammad [NFCRS, Nuclear Science and Technology Research Institute, P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of)

    2014-02-01

    A modified, selective, highly sensitive and accurate procedure for the determination of trace amounts of manganese and iron ions is established in the presented work. 3-(1-Methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid (MPPC) and graphene oxide (GO) were used in a glass column as chelating reagent and as adsorbent respectively prior to their determination by flame atomic absorption spectrometry. The adsorption mechanism of titled metals complexes on GO was investigated by using computational chemistry approach based on PM6 semi-empirical potential energy surface (PES). The effect of some parameters including pH, flow rate and volume of sample and type, volume and concentration of eluent, as well as the adsorption capacity of matrix ions on the recovery of Mn(II) and Fe(III) was investigated. The limit of detection was 145 and 162 ng L{sup −1} for Mn(II) and Fe(III), respectively. Calibration was linear over the range of 0.31–355 μg L{sup −1} for Mn(II) and 0.34–380 μg L{sup −1} for Fe(III) ions. The method was successfully applied for the determination of understudied ions in water, food and biological samples. - Highlights: • We use synthesized graphene oxide as adsorbent for SPE of Mn(II) and Fe(III) ions. • Adsorption mechanism was investigated by PM6 semi-empirical potential energy surface. • Detection limits were 145 and 162 ng L{sup −1} for Mn and Fe, respectively. • The preconcentration factor was 325 and sample flow rate is 8 mL min{sup −1}. • It was successfully applied to the determination of Mn and Fe ions in real samples.

  3. Analytical Method Validation of Gamma Spectrometric Procedure for the Determination of γ-Emitters in Environmental Samples

    It is internationally recognized that validation is necessary in analytical laboratories. The use of validated methods is important for an analytical laboratory to show its qualification and competency. This work describes the methods for validation of gamma spectrometric analytical procedure in the determination of some gamma emitters in environmental samples. The method was tested and validated in terms of repeatability, trueness, reproducibility in accordance with ISO guidelines using IAEA reference materials with different matrixes and compositions

  4. 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

  5. Microwave Digestion and Continuum Source Atomic Absorption Spectrometric Determination of Six Metal Elements in Medlar(Mespilus germanica L.) Fruit%微波消解-连续光源原子吸收法快速顺序测定枸杞果中的6种金属元素

    高向阳; 王银娟; 卢彬

    2011-01-01

    A new rapid method was established to determine metal elements in medlar fruit by microwave digestion and continuum source atomic absorption spectrometry.Samples were subjected to microwave digestion before simultaneous determination of six metal elements,including iron,zinc,copper,manganese,cadmium and lead.The established method presented a limit of detection ranging from 0.006070 to 0.04975 μg/L.The precision RSDs were between 1.5% and 5.0%(n = 12).The mean spike recoveries for the six metal elements ranged from 86.68% to 111.7%(n = 6).This method has been used to simultaneously determine iron,zinc,copper,manganese,cadmium and lead in medlar fruit with the benefits of rapidity,simplicity and low cost and satisfying results.%建立一种微波消解-连续光源原子吸收法快速测定枸杞果中金属元素的新方法。通过微波消解快速处理样品,用连续光源原子吸收法同时顺序测定枸杞果中的铁、锌、铜、锰、镉、铅6种金属元素,并对仪器使用条件、金属元素含量、精密度、检出限、回收率等进行研究。结果表明:方法检出限为0.006 07 0~0.04975μg/L,RSD为1.5%~5.0%,回收率为86.68%~111.7%。该法用于枸杞中6种金属元素的同时顺序测定,具有快速、简便、成本低廉等特点,分析结果令人满意。

  6. Atomic absorbtion spectrometric determination of platinum, palladium and rhodium in catalysts for automotive exhaust

    Analytical parameters of the electrothermal atomic absorption spectrometry method have been optimized for determination of platinum, palladium and rhodium in ceramic-supported catalysts for automobile exhaust gas treatment. Two chemical sample preparation methods have been proposed. In order to simplify the sample preparation procedure and to prevent the possible losses of platinum group metals the treatment of the previously ground sample with a mixture of mineral acids is recommended. (authors)

  7. Solid Phase Extraction of Lead Using Eggshell Membrane in Water Samples Prior to Graphite Furnace Atomic Absorption Spectrometric Determination%鸡蛋膜固相萃取-石墨炉原子吸收光谱法测定水样中的微量铅

    刘金; 彭元; 陈红梅; 程先忠

    2012-01-01

    鸡蛋膜是由蛋白质组成的一种纤维状的生物膜.本研究利用扫描电镜和红外光谱对鸡蛋膜的结构进行分析表征,证实其具有网状结构,表面存在着—OH、—COOH、—NH2等官能团,能与一些金属离子产生吸附和交换作用.在pH =6的条件下,用蛋膜作吸附剂分离富集水样中的微量铅,5 mL 3%的硝酸进行洗脱,然后采用石墨炉原子吸收光谱法进行测定.实验中对吸附分离介质、溶液流速、蛋膜用量、洗脱剂浓度及共存离子的影响等条件进行了优化和讨论.在最佳的实验条件下,蛋膜对铅的富集倍数为30,方法检出限(3σ)为0.017 ng/mL,相对标准偏差(RSD,n=11)为3.45%,加标回收率为96.0% ~ 104.2%.与现行的分离富集方法相比,建立的方法具有简单、无毒、成本低的优点,用于实际水样中铅的分析能够获得满意的结果.%A chicken eggshell membrane (ESM) is composed of many protein fibers, and available in large quantities as a by-product of the food industry. According to a study by Scanning Electron Microscope ( SEM ) and Fourier Transform Infrared ( FTIR) Spectrometry, the ESM with an intricate lattice network of stable and water-insoluble fibers, and special functional groups such as hydroxyl ( —OH) , carboxyl ( —COOH) , aminol ( —NH2 ) , showed an excellent potential for adsorption and exchange of metal ions. In this paper, the ESM was applied to separate and enrich Pb (II) from a water sample under a pH of 6. The trace lead eluted by 5 mL 3% HN03 was determined by using Graphite Furnace Atomic Absorption Spectrometry ( GFAAS ) . Important parameters, such as the sample pH, sample flow rate, concentration and volume of eluent, and interference of coexisting ions were comprehensively studied and optimized. Under the optimized conditions, an enrichment factor of 30 was obtained. The method detection limit for lead was 0.017 ng/mL (3

  8. Atomic emission and atomic absorption spectrometric analysis of high-purity powders for the production of ceramics

    Direct analysis methods and multistage combined analytical procedures for the determination of impurities at the μg/g level and the upper ng/g level in high-purity powders of Al2O3, AlN, Si3N4 and SiC are described. Results obtained with a novel direct slurry-atomization technique using a Babington nebulizer and inductively coupled plasma optical emission spectrometry (ICP-OES) are presented. A comparison of analysis results of combined analytical procedures including wet chemical decomposition and determinations with graphite furnace atomic absorption spectrometry (ETAAS) or ICP-OES with those of slurry-atomization ICP-OES show the capabilities of this technique for routine analysis in production control. Detection limits for Al, B, Ca, Co, Cu, Fe, Mg, Mn, Si, Ti, W, V, and Zn in the matrices mentioned are between 0.03 and 2.5 μg/g. For elemental concentrations ≥10 μg/g relative standard deviations of the measurements are generally below 10%. The technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of a series of the ceramic powders mentioned and comparative results of other direct techniques such as total reflection X-ray fluorescence spectrometry and instrumental neutron activation analysis. (orig.)

  9. Chromatographic separation and inductively coupled plasma atomic emission spectrometric determination of the rare earth metals contained in terbium

    The chromatographic separation of rare earth elements (REEs), prior to inductively coupled plasma atomic emission spectrometric (ICP-AES) measurements, using a column packed with 2-ethylexyl hydrogen 2-ethyl-hexylphosphonate (PC-88A)-loaded polymer resin in order to exclude spectral interferences was examined. A favourable separation of trace amounts of metals (La, Nd and Sm) from a large amount of terbium was achieved simply by elution with dilute hydrochloric acid. Trace lanthanum and neodymium in metallic terbium were determined by separation of the analyte ions from the matrix element followed by ICP-AES analysis. (author). 16 refs.; 5 figs.; 2 tabs

  10. 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

  11. Development of a mass spectrometrical isotope dilution analysis for determination of trace iodine levels and its application for food samples

    A mass spectrometrical isotope dilution procedure for the determination of trace amounts of iodine in various materials was developed using 129I as indicator isotope, based on the determination of the 129I/127I isotope relationship. Negative thermionization was used as ionization method. The analysis procedure, which worked with a standard deviation of between 0,1 and 10% (depending on material tested), was used to determine the iodine level of table salt - both iodized and normal salt (3-6 ppm and less than 0,006 ppm respectively), and food samples with an organic matrix. For comparison the iodine levels were also measured with an iodine-selective electrode. Special preparation and separation procedures were done to suit the sample material. A comparison of the levels of iodine concentration in various powdered milks which were measured by international collaborators using varying methods shows the superior reproducibility of the MS-IDA. (RB)

  12. Critical comparison of radiometric and mass spectrometric methods for the determination of radionuclides in environmental, biological and nuclear waste samples.

    Hou, Xiaolin; Roos, Per

    2008-02-11

    The radiometric methods, alpha (alpha)-, beta (beta)-, gamma (gamma)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry, resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. These methods are critically compared for the determination of long-lived radionuclides important for radiation protection, decommissioning of nuclear facilities, repository of nuclear waste, tracer application in the environmental and biological researches, these radionuclides include (3)H, (14)C, (36)Cl, (41)Ca, (59,63)Ni, (89,90)Sr, (99)Tc, (129)I, (135,137)Cs, (210)Pb, (226,228)Ra, (237)Np, (241)Am, and isotopes of thorium, uranium and plutonium. The application of on-line methods (flow injection/sequential injection) for separation of radionuclides and automated determination of radionuclides is also discussed. PMID:18215644

  13. Application of wall-stabilized plasma arc for the spectrometric determination of impurity elements in uranium yellow cake

    The application of a seeded wall-stabilized argon plasma arc as an excitation source for the emission spectrometric determination of some impurity elements in a sample of uranium yellow cake has been investigated. The sample was dissolved in nitric acid. Uranium was extracted from the sample solution using tributyl phosphate (TBP), and the aqueous solution was injected into the arc. The elements determined were Al, Ca, Fe, Mg, Mn, Mo, Sr and Zr. Limits of detection and precision of the technique are presented. The study of the influence of residual uranium in the nebulized solution on the intensity of spectral lines revealed that uranium concentrations up to 100 μg mL-1 have no significant interfering effect

  14. Determination of Cd(II, Zn(II and Ag(Iin different matrixes after solid phase extraction on sodium dodecyl sulfate(SDS-coated alumina as their 2,3 Di Hydro 2,3 paratolylQinazoline (1 H- 4 one (DPTQO by Flame atomic absorption spectrometric

    Farveh Raoufi

    2016-03-01

    Full Text Available A sensitive and selective solid phase extraction procedure for the determination of traces of Cd(II, Zn(II and Ag(I ions has been developed. An alumina-sodium dodecyl sulfate (SDS coated on with 2,3 Di Hydro 2,3 paratolylQinazoline (1 H- 4 one (DPTQO. The influences of the analytical parameters including pH and sample volume were investigated.Common coexisting ions did not interfere on the separation and determination of analytes under study. The adsorbed analytes were desorbed by using 6mL of 4 mol L−1 nitric acid. The responses are linear 0.02–0.85 µg mL-1 for Cd2+ ion0.01–0.90 µg mL-1 for Zn2+and0.02–0.92µg mL-1for Ag+ detection limit for Cd(II, Zn(II and Ag(I ions were found to be 1.4, 1.3 and1.12(ng mL-1, respectively.It was found that the recovery for Cd2+, Zn2+and Ag+ ions were 97.7, 98.2 and 98.0 with RSD of 1.9, 1.8 and 1.7. It was also observed that recovery for repeated recovery on the same solid phase not varies more than 3%. The presented procedurewas successfully applied for determination of analytes in radiology wastewater, amalgam, natural water and blood samples.

  15. Application and evaluation of the mass spectrometric isotope dilution technique in the determination of rare earths in geological materials

    Establishment of the experimental procedures employed in the rare earth element determination of geological samples by mass spectrometric isotope dilution analysis is discussed in the present work. The procedures involve preparation and calibration of the isotope tracers isotope dilution, dissolution in a teflon pressure vessel, chemical separation and isotope analysis using a fully automated Micromass VG ISOTOPES model 354 thermal ionization mass spectrometer. For the initial chemical separation of total rare earths the cationic resin was employed and HC1 and HNO3 acids as eluents. In the second step rare earths elements were separated into individual (La, Ce and Nd) and subgroups (Sm-Eu-Gd, Yb-Er-Dy) fractions using the same cationic resin and α-HIBA as eluent. Nine elements La, Ce, Nd, Sm, Eu, Gd, Dy, Er and Yb are determined by this method in the ''United States Geological Survey'' (USGS) standard samples GSP-1, AGV-1 and G-2, with an overall precision of +- 1 to 2% and an accuracy of 5%. The concentration of rare earth element determined in the standard sample PCC-1 showed that the total analytical blanks are in submicrogram levels. The concentration of rare earth elements in the same USGS standard samples were also determined by Instrumental neutron activation analysis, neutron activation analysis with chemical separation before irradiation and inductively coupled argon plasma spectroscopy. The chemical procedures employed for these methods are the same as that used for mass spectrometric isotope dilution. Based on the results obtained, each method was evaluated pointing out their merits and defects. The study clearly showed that the chemical procedure employed for all these techniques was satisfactory. (author)

  16. Determining Absorption, Emissivity Reduction, and Local Suppression Coefficients inside Sunspots

    Ilonidis, Stathis; Zhao, Junwei

    2010-01-01

    The power of solar acoustic waves is reduced inside sunspots mainly due to absorption, emissivity reduction, and local suppression. The coefficients of these power-reduction mechanisms can be determined by comparing time-distance cross-covariances obtained from sunspots and from the quiet Sun. By analyzing 47 active regions observed by SOHO/MDI without using signal filters, we have determined the coefficients of surface absorption, deep absorption, emissivity reduction, and local suppression....

  17. 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)

  18. Geração eletroquímica do hidreto de selênio em sistema de injeção em fluxo com detecção por espectrometria de absorção atômica com chama Ar-Glp Electrochemical hydride generation for selenium determination in a flow injection system with Air-GLP flame atomic absorption spectrometric detection

    Luís Fernando Rebel Machado; Antonio Octavio Jacintho; Maria Fernanda Giné

    2000-01-01

    This paper presents a system for electrochemical hydride generation using flow-injection and atomic absorption spectrometry to determine selenium in biological materials. The electrolytic cell was constructed by assembling two reservoirs, one for the sample and the other for the electrolytic solution separated by a Nafion membrane. Each compartment had a Pt electrode. The sample and electrolyte flow-rates, acidic media, and applied current were adjusted to attain the best analytical performan...

  19. Determination of lithium and potassium in uranium oxide powders and pellets by Flame Atomic Emission Spectrometric method

    The present paper describes a method developed at Control Laboratory, NFC which includes prior separation of lithium and potassium from uranium matrix before their measurements. Solvent extraction, using Tri-n-Butyl Phosphate (TBP) in CCI4 followed by Tri-n-Octyl Phosphine Oxide (TOPO) in CCI4, is employed for prior separation of Li and K. The resultant aqueous solution was analyzed by Flame-Atomic Emission Spectrometric (AES) method. Solvent extraction conditions are optimized for measurement of Li and K in the same aliquot. Experimental conditions such as instrument calibration, flame condition, fuel flow, sample flow rate through nebulizer, burner height etc. are also optimized. Under the optimal condition the detection limits achieved for lithium is 0.02 ppm and 0.2 ppm for potassium. A RSD of ± 3 % for Li at 0.05 ppm and ± 4% for K at 1 ppm level has been achieved in this method. The results of lithium in the sample are compared with the values obtained by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Similarly, values of potassium are compared with Flame-Atomic Absorption Spectrometry (Flame-AAS) technique. The comparisons are in good agreement. The above method is simple, sensitive, reproducible and can be used for measurement of lithium and potassium in UO2 powder and pellets on regular basis

  20. Atomic absorption spectroscopic, conductometric and colorimetric methods for determination of some fluoroquinolone antibacterials using ammonium reineckate

    Al-Ghannam, Sheikha M.

    2008-04-01

    Three accurate, rapid and simple atomic absorption spectrometric (AAS), conductometric and colorimetric methods were developed for the determination of gatifloxacin (GTF), moxifloxacin (MXF) and sparfloxacin (SPF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in acetone. The pink coloured complexes were determined either by AAS or colorimetrically at λmax 525 nm directly using the dissolved complex. Using conductometric titration, the studied drugs could be evaluated in 50% (v/v) acetone. The optimizations of various experimental conditions were described. Optimum concentration ranges for the determination of GTF, MXF and SPF were 5.0-150, 40-440 μg mL -1 and 0.10-1.5 mg mL -1 using atomic absorption (AAS), conductometric and colorimetric methods, respectively. Detection and quantification limits are ranges from 1.5 to 2.3 μg mL -1 using AAS method or 30-45 μg mL -1 using colorimetric method. The proposed procedures have been applied successfully to the analysis of these drugs in pharmaceutical formulations and the results are favourably comparable to the reference methods.

  1. Automated sequential injection-microcolumn approach with on-line flame atomic absorption spectrometric detection for implementing metal fractionation schemes of homogeneous and non-homogeneous solid samples of environmental interest

    Chomchoei, Roongrat; Miró, Manuel; Hansen, Elo Harald;

    2005-01-01

    spectrometric detection and used for the determination of Cu as a model analyte, the potentials of this novel hyphenated approach are demonstrated by the ability of handling up to 300 mg sample of a nonhomogeneous sewage amended soil (viz., CRM 483). The three steps of the endorsed Standards, Measurements, and...

  2. The Flame Spectrometric Determination of Calcium in Fruit Juice by Standard Addition.

    Strohl, Arthur N.

    1985-01-01

    Provides procedures to measure the calcium concentration in fruit juice by atomic absorption. Fruit juice is used because: (1) it is an important consumer product; (2) large samples are available; and (3) calcium exists in fruit juice at concentrations that do not require excessive dilution or preconcentration prior to measurement. (JN)

  3. Internal standard method in α spectrometric determination of uranium and thorium radioisotopes using instrumental neutron activation analysis

    A new approach to α spectrometric determination of the radioisotopes of uranium and thorium was developed for environmental samples based on 238U and 232Th as internal standards. 238U and 232Th were accurately determined in the sample by simultaneous instrumental neutron activation analysis. Other aliquots of the sample were totally dissolved, uranium and thorium separated by anion exchange, and thin sources electroplated for α spectrometry. From the known mass concentrations of 238U and 232Th, their activity concentrations were obtained, and thus from the relative ratios of uranium (234U, 235U, 238U) and thorium (228Th, 230Th, 232Th) radioisotopes in the α spectra, the absolute isotopic activity concentrations were derived. The advantages of the procedure are that neither the chemical recovery of the radiochemical separation nor the counting efficiency of the α spectrometer is required; the use of internal standards eliminates the need for addition of expensive, calibrated, external radioisotopic tracers such as 232U and 229Th. The new approach was tested on some certified environmental reference materials and compared with the classical method using external radioisotopic tracers. It may advantageously be combined with the standard approach to obtain an independent set of data for quality control. 25 refs

  4. 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

  5. Partial vapor-phase hydrolysis of peptide bonds: A method for mass spectrometric determination of O-glycosylated sites in glycopeptides

    Mirgorodskaya, E; Hassan, H; Wandall, H H;

    1999-01-01

    resulting mass spectra allowed unambiguous determination of the glycosylation sites. Examples are shown with mannosyl- and mucin-type glycopeptides. Performing the hydrolysis in vapor eliminates the risk for contamination of the sample with impurities from the reagents, thus allowing analysis of the......In this study we present a method for determination of O-glycosylation sites in glycopeptides, based on partial vapor-phase acid hydrolysis in combination with mass spectrometric analysis. Pentafluoropropionic acid and hydrochloric acid were used for the hydrolysis of glycosylated peptides. The...... reaction conditions were optimized for efficient polypeptide backbone cleavages with minimal cleavage of glycosidic bonds. The glycosylated residues were identified by mass spectrometric analysis of the hydrolytic cleavage products. Although glycosidic bonds are partially cleaved under acid hydrolysis, the...

  6. Determination of the total absorption peak in an electromagnetic calorimeter

    Cheng, Jia-Hua; Wang, Zhe; Lebanowski, Logan; Lin, Guey-Lin; Chen, Shaomin

    2016-08-01

    A physically motivated function was developed to accurately determine the total absorption peak in an electromagnetic calorimeter and to overcome biases present in many commonly used methods. The function is the convolution of a detector resolution function with the sum of a delta function, which represents the complete absorption of energy, and a tail function, which describes the partial absorption of energy and depends on the detector materials and structures. Its performance was tested with the simulation of three typical cases. The accuracy of the extracted peak value, resolution, and peak area was improved by an order of magnitude on average, relative to the Crystal Ball function.

  7. Determination of the total absorption peak in an electromagnetic calorimeter

    Cheng, Jia-Hua; Lebanowski, Logan; Lin, Guey-Lin; Chen, Shaomin

    2016-01-01

    A physically-motivated function was developed to accurately determine the total absorption peak in an electromagnetic calorimeter and to overcome biases present in many commonly used methods. The function is the convolution of a detector resolution function with the sum of a delta function, which represents the complete absorption of energy, and a tail function, which describes the partial absorption of energy and depends on the detector materials and structures. Its performance was tested with the simulation of three typical cases. The accuracy of the extracted peak value, resolution, and peak area was improved by an order of magnitude on average, relative to the Crystal Ball function.

  8. Direct atomic absorption determination of cadmium in solid foodstuffs

    A procedure is proposed for the direct rapid determination of cadmium in solid foodstuff samples by atomic absorption analysis using a modified Lvov furnace equipped with a graphite partition filter. The use of this furnace eliminates the step of transferring a solid sample to solution, allows calibration solutions to be employed properly in the direct analysis of solid samples, suppresses unselective absorption, and substantially shortens the time of analysis. 12 refs., 3 figs., 2 tabs

  9. Determination of trace amounts of scandium by atomic absorption spectroscopy.

    Chau, Y K

    1968-05-01

    Optimum instrumental conditions were investigated for the determination of trace quantities of scandium by atomic-absorption spectroscopy. Enhancement effects by organic solvents and by complex extractions were also studied. (46)Sc was used to establish the optimum extraction conditions. A sensitivity of 0.06 ppm of Sc was observed when using extraction into oxine-butanol and atomic absorption was measured with an acetylene-nitrous oxide flame. PMID:18960315

  10. Spectrometric Methods Used to Determine Heavy Metals and Total Cyanides in Accidental Polluted Soils

    A. Mihaly-Cozmuta; L. M. Cozmuta; V. Viman; Gh. Vatca; Varga, C.

    2005-01-01

    The study presents the level of soil pollution in the area adjacent to three sedimentation ponds as a result of an environmental accident. Soil samples from various sites have been collected and analyzed to determine the concentration of heavy metals (Cu, Pb, Zn) and total cyanides. The analysis methods used were ICP-AES for heavy metals and the colorimetric for total cyanides. The accuracy of both methods is determined subject to the reproducibility of the results. The values of determined c...

  11. 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)

  12. Determination of trace elements in cosmetic by X-ray spectrometric techniques (1994-95)

    Trace elements in cosmetic such as talcum powder, baby powder, Myanma Thanakh were determined by EDXRF analysis. The measurement system consists of a Cd-109 annual excitation source, a Si(Li) detector, H.V. power supply, a spectroscopy amplifier, a multichannel analyser and a personnel computer. The samples were prepared as pressed pellets and measured by emission transmission technique. The accuracy was determined by analysing standard reference material, SOIL-7 from IAEA. (author)

  13. Comparison of accelerator mass spectrometric measurement with liquid scintillation counting measurement for the determination of {sup 14}C in environmental samples

    Yasuike, Kaeko, E-mail: k-yasuike@hokuriku-u.ac.j [Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3, Kanagawa-machi, Kanazawa, Ishikawa 920-1181 (Japan); Yamada, Yoshimune [Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3, Kanagawa-machi, Kanazawa, Ishikawa 920-1181 (Japan); Amano, Hikaru [AMS Management Section, Japan Atomic Energy Agency, 4-24, Minato-machi, Mutsu, Aomori 035-0064 (Japan)

    2010-04-15

    The concentrations of organically-bound {sup 14}C in tree-ring cellulose of a Japanese Black Pine grown in Shika-machi (37.0 deg. N, 136.8 deg. E) and those of a Japanese Cedar grown in Kanazawa (36.5 deg. N, 136.7 deg. E), Japan, were analyzed for the ring-years from 1989 to 1998 by the accelerator mass spectrometric measurement. The results were compared with those of the same samples analyzed by the liquid scintillation counting measurement to determine the reliability of liquid scintillation counting measurement. An important result of this study is that the sensitivity and reproducibility of accelerator mass spectrometric measurement was almost equal to that of liquid scintillation counting measurement.

  14. 'Age' determination of irradiated materials utilizing inductively coupled plasma mass spectrometric (ICP-MS) detection

    A gas pressurized extraction chromatography (GPEC) system has been developed to perform elemental separations on radioactive samples to determine total and isotopic compositions of Cs and Ba from an irradiated salt sample, fuel sample and two sealed radiation sources. The GPEC system employs compressed nitrogen to move liquid through the system, compared to gravity or pumped liquids that are typically used for separations. A commercially available Sr-ResinTM was used to perform the separation for the above mentioned analytes. A 1% acetic acid solution was determined to be the best extractant for Ba. A flow rate of 0.1 mL/min was determined to be optimal for the separation of Ba. Complete recovery of the Cs and Ba was achieved, within the systematic uncertainties of the experiments. (author)

  15. Advanced miniaturized plasmas as atomic spectrometric detectors for elemental determinations and speciation in environmental sciences

    Miniaturized plasmas can be well used for determinations of the elements in a wide variety of environmentally relevant samples. All analytes, which can be brought in the gaseous phase can be easily determined with a wide diversity of microplasmas, whereas in liquids glow discharges where the sample solution serves as one of the electrodes is useful. For monitoring metals in gases also possibilities are available. The range of applications of the devices certainly still can be widened considerably when using mass spectrometry detection. By on-line combinations with chromatography the devices certainly also are very useful for metal speciation work.

  16. Simultaneous Laser Thermal Lens Spectrometric Determination of Trace Platinum and Palladium in an Aqueous Solution

    ZHANG,Xiao-Ling(张小玲); YAN,Hong-Tao(阎宏涛)

    2002-01-01

    A selective and sensitive method for determination of platinum and palladium(Ⅱ) in an aqueous solntion simultaneously by laser thermal lens spectrometry, based on the complex reaction of 2- (3,5-dichloropyridylazo)-5- dimethylaminoamiline (3,5-diCl-PADMA) with platinum and palladium, has been developed. It is shown that the palladium complex can be formed at room temperature, while the platinum complex can be only formed after being heated in a boiling water bath. By using this difference of reaction temperature and the characteristic of the complexes mentioned above, the method for simultaneous determination of platinum and palladium was established in an aqueous solution without a pre-separation. The results show that the dynamic linear ranges of determination for platinum and pallladium are 0.005-0.04 μg/mL and 0.005-0.25 μg/mL respectively, and that the detection limits are both 0.002 μg/mL. The method has been applied to the determination of platinum and palladium simultaneously in alloy and catalyst samples with satisfactory results.

  17. Simultaneous Laser Thermal Lens Spectrometric Determination of Trace Platinum and Palladium in an Aquesous Solution

    张小玲; 阎宏涛

    2002-01-01

    A selective and sensitive method for determination of platinum and palladium(Ⅱ)in an aqueous solution simultaneously by laser thermal lens spectrometry,based on the complex reaction of 2-(3,5-dichloropyridylazo)-5-dimethylaminoamiline(3,5-diCl-PADMA) with platinum and palladium,has been developed.It is shown that the palladium complex can be fromed at room temperature, while the platinum complex can be only formed after being heated in a boiling water bath.By using this difference of reaction temperature and the characteristic of the complexes mentioned above,the method for simultaneous determination of platinum and palladium was established in an aqueous solution without a pre-separation.The results show that the dynamic linear ranges of determination for platinum and palladium are 0.005-0.04μg/mL and 0.005-0.25μg/mL respectively,and that the detection limits are both 0.002/μg/mL.The method has been applied to the determination of platinum and palladium simultaneously in alloy and catalyst samples with satisfactory results.

  18. Determination of rhenium in molybdenite by X-ray fluorescence. A combined chemical-spectrometric technique

    Solt, M.W.; Wahlberg, J.S.; Myers, A.T.

    1969-01-01

    Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 ??g of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods. ?? 1969.

  19. A photon spectrometric dose-rate constant determination for the Advantage Pd-103 brachytherapy source

    Purpose: Although several dosimetric characterizations using Monte Carlo simulation and thermoluminescent dosimetry (TLD) have been reported for the new Advantage Pd-103 source (IsoAid, LLC, Port Richey, FL), no AAPM consensus value has been established for the dosimetric parameters of the source. The aim of this work was to perform an additional dose-rate constant (Λ) determination using a recently established photon spectrometry technique (PST) that is independent of the published TLD and Monte Carlo techniques. Methods: Three Model IAPD-103A Advantage Pd-103 sources were used in this study. The relative photon energy spectrum emitted by each source along the transverse axis was measured using a high-resolution germanium spectrometer designed for low-energy photons. For each source, the dose-rate constant was determined from its emitted energy spectrum. The PST-determined dose-rate constant (PSTΛ) was then compared to those determined by TLD (TLDΛ) and Monte Carlo (MCΛ) techniques. A likely consensus Λ value was estimated as the arithmetic mean of the average Λ values determined by each of three different techniques. Results: The average PSTΛ value for the three Advantage sources was found to be (0.676±0.026) cGyh-1 U-1. Intersource variation in PSTΛ was less than 0.01%. The PSTΛ was within 2% of the reported MCΛ values determined by PTRAN, EGSnrc, and MCNP5 codes. It was 3.4% lower than the reported TLDΛ. A likely consensus Λ value was estimated to be (0.688±0.026) cGyh-1 U-1, similar to the AAPM consensus values recommended currently for the Theragenics (Buford, GA) Model 200 (0.686±0.033) cGyh-1 U-1, the NASI (Chatsworth, CA) Model MED3633 (0.688±0.033) cGyh-1 U-1, and the Best Medical (Springfield, VA) Model 2335 (0.685±0.033) cGyh-1 U-1103Pd sources. Conclusions: An independent Λ determination has been performed for the Advantage Pd-103 source. The PSTΛ obtained in this work provides additional information needed for establishing a more

  20. Determination of fixed water in rocks by infrared absorption

    Breger, I.A.; Chandler, J.C.

    1969-01-01

    An infrared absorption technique has been developed for the quantitative determination of "fixed water" (H2O+) in rocks. Potassium bromide disks containing 2-mg samples are scanned in the 3-??m spectral region and absorption at 2.96 ??m is determined. Although the exact nature of this peak is not known, other than that it is caused by an interaction between the potassium bromide and hydroxyl groups and water, it can be used for quantitative analysis. Rock samples, other than those containing significant percentages of clay minerals, can be analyzed with a standard deviation of 0.26%.

  1. Determination of γ-spectrometric parameters for some chloride salt solutions

    The mass attenuation coefficients, atomic cross-sections and effective atomic numbers are determined for LiCl, NaCl and KCl solutions with contents up to 0.2 g cm-3.The energies used are 0.511, 0.662 and 1.274 keV. The combined results were employed to determine the mass attenuation coefficients and atomic cross-sections of the salts and water in the solutions. The results are compared with the calculated values from elemental data. It was found that the mass attenuation coefficients and corresponding total cross-sections are, in general, less from measurement than from tabulated data, either for water or for the chloride salts

  2. Mass-spectrometric determination of serum cortisol: comparison of data from two independent laboratories

    Isotope dilution and mass spectrometry were used in two independent laboratories to determine cortisol in 15 plasma and serum pools used in the British and German national schemes for the external quality assessment of routine assays. For the concentration range 240-700 nmol/L, differences between the data obtained by the two laboratories were generally less than 4% but were approximately 7% in two instances. The discrepancies are nevertheless small in comparison with the bias observed for many routine assays

  3. Determination of rhenium in molybdenite by X-ray fluorescence: A combined chemical-spectrometric technique.

    Solt, M W; Wahlberg, J S; Myers, A T

    1969-01-01

    Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 microg of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods. PMID:18960464

  4. Microwave plasma atomic emission spectrometric determination of Ca, K and Mg in various cheese varieties.

    Ozbek, Nil; Akman, Suleyman

    2016-02-01

    Microwave plasma-atomic emission spectrometry (MP-AES) was used to determine calcium, magnesium and potassium in various Turkish cheese samples. Cheese samples were dried at 100 °C for 2 days and then digested in a mixture of nitric acid/hydrogen peroxide (3:1). Good linearities (R(2) > 0.999) were obtained up to 10 μg mL(-1) of Ca, Mg and K at 445.478 nm, 285.213 nm and 766.491 nm, respectively. The analytes in a certified reference milk powder sample were determined within the uncertainty limits. Moreover, the analytes added to the cheese samples were recovered quantitatively (>90%). All determinations were performed using aqueous standards for calibration. The LOD values for Ca, Mg and K were 0.036 μg mL(-1), 0.012 μg mL(-1) and 0.190 μg mL(-1), respectively. Concentrations of Ca, K and Mg in various types of cheese samples produced in different regions of Turkey were found between 1.03-3.70, 0.242-0.784 and 0.081-0.303 g kg(-1), respectively. PMID:26304350

  5. A mass spectrometric method to determine activities of enzymes involved in polyamine catabolism

    Moriya, Shunsuke; Iwasaki, Kaori [Department of Molecular Medicine, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kami-kitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Samejima, Keijiro, E-mail: samejima-kj@igakuken.or.jp [Department of Molecular Medicine, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kami-kitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Takao, Koichi [Faculty of Pharmaceutical Sciences, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295 (Japan); Kohda, Kohfuku [Research Institute of Pharmaceutical Sciences, Musashino University, 1-1-20 Shinmachi, Nishitokyo, Tokyo 202-8585 (Japan); Hiramatsu, Kyoko; Kawakita, Masao [Department of Molecular Medicine, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kami-kitazawa, Setagaya-ku, Tokyo 156-8506 (Japan)

    2012-10-20

    Highlights: Black-Right-Pointing-Pointer Compounds in polyamine catabolic pathway were determined by a column-free ESI-TOF MS. Black-Right-Pointing-Pointer N{sup 1}- and N{sup 8}-acetylspermidine were determined by a column-free ESI-MS/MS. Black-Right-Pointing-Pointer The method was applied to determine activities of APAO, SMO, and SSAT in the pathway. Black-Right-Pointing-Pointer The assay method contained stable isotope-labeled natural substrates. Black-Right-Pointing-Pointer It is applicable to biological samples containing natural substrate and product. - Abstract: An analytical method for the determination of three polyamines (putrescine, spermidine, and spermine) and five acetylpolyamines [N{sup 1}-acetylspermidine (N{sup 1}AcSpd), N{sup 8}-acetylspermidine (N{sup 8}AcSpd), N{sup 1}-acetylspermine, N{sup 1},N{sup 8}-diacetylspermidine, and N{sup 1},N{sup 12}-diacetylspermine] involved in the polyamine catabolic pathway has been developed using a hybrid tandem mass spectrometer. Heptafluorobutyryl (HFB) derivatives of these compounds and respective internal standards labeled with stable isotopes were analyzed simultaneously by TOF MS, based on peak areas appearing at appropriate m/z values. The isomers, N{sup 1}AcSpd and N{sup 8}AcSpd were determined from their fragment ions, the acetylamidopropyl and acetylamidobutyl groups, respectively, using MS/MS with {sup 13}C{sub 2}-N{sup 1}AcSpd and {sup 13}C{sub 2}-N{sup 8}AcSpd which have the {sup 13}C{sub 2}-acetyl group as an internal standard. The TOF MS method was successfully applied to measure the activity of enzymes involved in polyamine catabolic pathways, namely N{sup 1}-acetylpolyamine oxidase (APAO), spermine oxidase (SMO), and spermidine/spermine N{sup 1}-acetyltransferase (SSAT). The following natural substrates and products labeled with stable isotopes considering the application to biological samples were identified; for APAO, [4,9,12-{sup 15}N{sub 3}]-N{sup 1}-acetylspermine and [1,4,8-{sup 15}N{sub 3

  6. Determination of suvorexant in human plasma using 96-well liquid-liquid extraction and HPLC with tandem mass spectrometric detection.

    Breidinger, S A; Simpson, R C; Mangin, E; Woolf, E J

    2015-10-01

    A method, using liquid chromatography with tandem mass spectrometric detection (LC-MS/MS), was developed for the determination of suvorexant (MK-4305, Belsomra(®)), a selective dual orexin receptor antagonist for the treatment insomnia, in human plasma over the concentration range of 1-1000ng/mL. Stable isotope labeled (13)C(2)H3-suvorexant was used as an internal standard. The sample preparation procedure utilized liquid-liquid extraction, in the 96-well format, of a 100μL plasma sample with methyl t-butyl ether. The compounds were chromatographed under isocratic conditions on a Waters dC18 (50×2.1mm, 3μm) column with a mobile phase consisting of 30/70 (v/v %) 10mM ammonium formate, pH3/acetonitrile at a flow rate of 0.3mL/min. Multiple reaction monitoring of the precursor-to-product ion pairs for suvorexant (m/z 451→186) and (13)C(2)H3-suvorexant (m/z 455→190) on an Applied Biosystems API 4000 tandem mass spectrometer was used for quantitation. Intraday assay precision, assessed in six different lots of control plasma, was within 10% CV at all concentrations, while assay accuracy ranged from 95.6 to 105.0% of nominal. Quality control (QC) samples in plasma were stored at -20°C. Initial within day analysis of QCs after one freeze-thaw cycle showed accuracy within 9.5% of nominal with precision (CV) of 6.7% or less. The plasma QC samples were demonstrated to be stable for up to 25 months at -20°C. The method described has been used to support clinical studies during Phase I through III of clinical development. PMID:26343269

  7. Gas chromatographic-mass spectrometric determination of ethyl carbamate in alcoholic beverages.

    Lau, B P; Weber, D; Page, B D

    1987-07-31

    A sensitive and specific method based on gas chromatography-mass spectrometry for the quantitative determination of ethyl carbamate in table wines, fortified wines (such as ports and sherries), distilled spirits, brandies and liqueurs has been developed. Three characteristic ions from ethyl carbamate [m/z 89 (molecular ion), 74 and 62] were monitored in the selected-ion monitoring (SIM) mode. The lowest detection limit (based on the response on the m/z 62 ion) was estimated to be 0.5 ng/g (ppb). Additional confirmation techniques, including high-resolution SIM, and methane or isobutane chemical ionization are described. PMID:3654867

  8. A computer program for nuclear fuel burnup determination using gamma spectrometric methods

    In the end of its service life in the reactor, the fuel needs to be characterized for reasons relating both to safety and economy. The main investigations carried out are oriented towards verifying the fuel cladding integrity and determining the fissile content and the fuel burnup. A computer program for fast burnup evaluation was developed at the Post-Irradiation Examination Laboratory (PIEL) from INR Pitesti, the only laboratory of this kind in Romania. The input data consists, on one hand, of axial and radial gamma-scanning profiles (for the experimental evaluation of the number of nuclei of a given fission product - selected as burnup monitor - in the end of irradiation) and, on the other hand, of the history of irradiation (the time length and relative value of the neutron flux for each step of irradiation). Using the equation for the build-up and decay of the burnup monitor during irradiation the flux value is iteratively adjusted until the calculated number of nucleus is equal to the experimental one. Then the flux value is used in the equations of evolution of the fissile and fertile nuclei to determine the number of fissions and consequently the fuel burnup. The program was successfully used in the analysis of more then one hundred of TRIGA and CANDU-type fuel rods. An experimental result is reported in some details. (authors)

  9. Segregation during crystal growth from melt and absorption cross section determination by optical absorption method

    ZHANG QingLi; YIN ShaoTang; SUN DunLu; WAN SongMing

    2008-01-01

    Segregation during crystal growth from melt under two conditions is studied by using crystal mass, which can be measured easily, as an independent variable, and a method to determine the effective segregation coefficient and absorption cross section of optical dopant is given. When the segregated solute disperses into the whole or just a part of melt homogenously, the concentration Cs in solid interface will change by different formulas. If the crystal growth interface is conical and segregated solute disperses into melt in total or part, the solute concentration at r=2/3R, where r is the distance from the growth cross section center and R the crystal radius, is independent on the shape of the crystal growth interface, and its variation at r=2/3R can be regarded as the result from crystal growth in flat interface. With Cs variation formula in solid and absorption cross section σ for optical dopant, the absorption coefficients along the crystal growth direction can be calculated, and the corresponding experimental value can be obtained through the crystal optical absorption spectra. By minimizing the half sum, whose independent variables are k, △W or σ, of the difference square between the calculated and experimental absorp-tion coefficients from one or more absorption peaks along the crystal growth di-rection, k and σ, or k and △W, can be determined at the same time through the Levenberg-Marquardt iteration method. Finally, the effective segregation coefficient k, △W and absorption cross sections of Nd:GGG were determined, the results fitted by two formula gave more closed effective segregation coefficient, and the value △W also indicates that the segregated dopant had nearly dispersed into the whole melt. Experimental results show that the method to determine effective segregation coefficient k, △W and absorption cross sections σ is convenient and reliable, and the two segregation formulas can describe the segregation during the crystal growth from

  10. Determination of rare earth elements by liquid chromatographic separation using inductively coupled plasma mass spectrometric detection

    High-performance liquid chromatography (HPLC) is used to separate the rare earth elements (REEs) prior to detection by inductively coupled plasma mass spectrometry (ICP-MS). The use of HPLC-ICP-MS in series combines the separation power and speed of HPLC with the sensitivity, isotopic selectivity and speed of ICP-MS. The detection limits for the REEs are in the sub-ng ml-1 range and the response is linear over four orders of magnitude. A preliminary comparison of isotope dilution and external standard results for the determination of REEs in National Institute of Standards and Technology (NIST) Standard Reference Material (SRM 1633a) Fly Ash is presented. (author)

  11. Simultaneous kinetic spectrometric determination of three flavonoid antioxidants in fruit with the aid of chemometrics

    Sun, Ruiling; Wang, Yong; Ni, Yongnian; Kokot, Serge

    2014-03-01

    A simple, inexpensive and sensitive kinetic spectrophotometric method was developed for the simultaneous determination of three anti-carcinogenic flavonoids: catechin, quercetin and naringenin, in fruit samples. A yellow chelate product was produced in the presence neocuproine and Cu(I) - a reduction product of the reaction between the flavonoids with Cu(II), and this enabled the quantitative measurements with UV-vis spectrophotometry. The overlapping spectra obtained, were resolved with chemometrics calibration models, and the best performing method was the fast independent component analysis (fast-ICA/PCR (Principal component regression)); the limits of detection were 0.075, 0.057 and 0.063 mg L-1 for catechin, quercetin and naringenin, respectively. The novel method was found to outperform significantly the common HPLC procedure.

  12. Gamma-ray spectrometric enrichment determination of a low enriched UF6 sample

    Non-destructive gamma-ray spectroscopic measurements have been done on a solid 80-gram UF6 sample in the framework of an interlaboratory measurement evaluation programme for isotopic abundance measurements on low enriched UF6. In the ECN measurements the photopeak areas of the 185.72 keV gamma-rays of 23'5U have been determined with different peak evaluation methods. In spite of the rather large spread in un-certainty values between the different methods, no statistically significant differences in the 235U atomic abundance values have been obtained. The average measured 235U atomic abundance in uranium is 3.480% with a relative uncertainty of 0.2% (2 σ confidence level). The certified value is 3.5001% with a relative uncertainty of 0.03% (2 σ). An explanation for this discrepancy has not been found. (author). 8 refs.; 7 figs.; 20 tabs

  13. The determination of zirconium by atomic absorption spectrophotometry

    The interference of iron in the determination of zirconium by atomic absorption spectrophotometry was studied. Attempts were made to emininate this interference by complexing the iron with EDTA, ascorbic acid and hydrazine; also by the addition of ammonium fluoride to the solution. Some experiments were carried out in order to explain the results obtained

  14. Determination of long-lived radionuclides at ultratrace level using advanced mass spectrometric techniques

    Determination of long-lived radionuclides at sub-fg concentration level is a challenging task in analytical chemistry. Inductively coupled plasma mass spectrometry (ICP-MS) with its ability to provide the sensitive and fast multielemental analysis is one of the most suitable method for the measurements of long lived radionuclides in the trace and ultra trace concentration range. In present the Ph.D. study a variety of procedures have been developed permitting the sub fg ml-1 determination of long-lived radionuclides (e.g. U, Th, Pu) as well as 226Ra (T1/2 = 1600 y) and 90Sr (T1/2= 28.1 y) in different samples. In order to avoid isobaric interferences, to increase the sensitivity, precision and accuracy of the methods the application of different techniques: pre-concentration of the sample, off-line separation on the crown resin, measurements under cold plasma conditions, using microconcentric nebulizers (e.g DIHEN, DS-5) or the application of LA-ICP-MS for sample introduction have been studied. The limits of detection for different radionuclides was significantly improved in comparison to the ones reported in the literature, and, depending on the method applied, was varied from 10-15 to 10-18 g ml-1 concentration range. In addition to the analysis of long lived radionuclides, some other elements, that can present potential interest to the analyzed sample, were measured within the framework of the present study. Laser ablation inductively coupled plasma mass spectrometry (LAICP- MS) was used to produce images of element distribution in 20μm m thin sections of human brain tissue. The sample surface was scanned (raster area ∝80 mm2) with a focused laser beam (wavelength 213 nm, diameter of laser crater 50μm, and laser power density 3x109 W cm-2) in a cooled laser ablation chamber developed for these measurements. Cross sections of human brain samples - hippocampus as well as brain tissues infected and non-infected with Glioblastoma Multiforme (tumor cells) were

  15. Honeybee Venom Proteome Profile of Queens and Winter Bees as Determined by a Mass Spectrometric Approach

    Ellen L. Danneels

    2015-10-01

    Full Text Available Venoms of invertebrates contain an enormous diversity of proteins, peptides, and other classes of substances. Insect venoms are characterized by a large interspecific variation resulting in extended lists of venom compounds. The venom composition of several hymenopterans also shows different intraspecific variation. For instance, venom from different honeybee castes, more specifically queens and workers, shows quantitative and qualitative variation, while the environment, like seasonal changes, also proves to be an important factor. The present study aimed at an in-depth analysis of the intraspecific variation in the honeybee venom proteome. In summer workers, the recent list of venom proteins resulted from merging combinatorial peptide ligand library sample pretreatment and targeted tandem mass spectrometry realized with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS/MS. Now, the same technique was used to determine the venom proteome of queens and winter bees, enabling us to compare it with that of summer bees. In total, 34 putative venom toxins were found, of which two were never described in honeybee venoms before. Venom from winter workers did not contain toxins that were not present in queens or summer workers, while winter worker venom lacked the allergen Api m 12, also known as vitellogenin. Venom from queen bees, on the other hand, was lacking six of the 34 venom toxins compared to worker bees, while it contained two new venom toxins, in particularly serine proteinase stubble and antithrombin-III. Although people are hardly stung by honeybees during winter or by queen bees, these newly identified toxins should be taken into account in the characterization of a putative allergic response against Apis mellifera stings.

  16. Honeybee venom proteome profile of queens and winter bees as determined by a mass spectrometric approach.

    Danneels, Ellen L; Van Vaerenbergh, Matthias; Debyser, Griet; Devreese, Bart; de Graaf, Dirk C

    2015-11-01

    Venoms of invertebrates contain an enormous diversity of proteins, peptides, and other classes of substances. Insect venoms are characterized by a large interspecific variation resulting in extended lists of venom compounds. The venom composition of several hymenopterans also shows different intraspecific variation. For instance, venom from different honeybee castes, more specifically queens and workers, shows quantitative and qualitative variation, while the environment, like seasonal changes, also proves to be an important factor. The present study aimed at an in-depth analysis of the intraspecific variation in the honeybee venom proteome. In summer workers, the recent list of venom proteins resulted from merging combinatorial peptide ligand library sample pretreatment and targeted tandem mass spectrometry realized with a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS/MS). Now, the same technique was used to determine the venom proteome of queens and winter bees, enabling us to compare it with that of summer bees. In total, 34 putative venom toxins were found, of which two were never described in honeybee venoms before. Venom from winter workers did not contain toxins that were not present in queens or summer workers, while winter worker venom lacked the allergen Api m 12, also known as vitellogenin. Venom from queen bees, on the other hand, was lacking six of the 34 venom toxins compared to worker bees, while it contained two new venom toxins, in particularly serine proteinase stubble and antithrombin-III. Although people are hardly stung by honeybees during winter or by queen bees, these newly identified toxins should be taken into account in the characterization of a putative allergic response against Apis mellifera stings. PMID:26529016

  17. Liquid Chromatography-Tandem Mass Spectrometric Assay for Determination of Stavudine in Human Plasma

    Fengdan Jin

    2014-01-01

    Full Text Available A LC-MS/MS method for determination of stavudine in human plasma was established and validated, and it was applied to the pharmaceutical formulations bioequivalence study. 0.5 mL plasma sample was extracted by liquid-liquid extraction. Stavudine was detected by a LC-MS/MS system. The pharmacokinetic parameters of stavudine in different formulations were calculated by noncompartment model statistics. The method was linear over the concentration ranges 5.00–1000 ng/mL in plasma. The intra- and interassay relative standard deviation (RSD was <10%. The average accuracies for the assay at three concentrations (5.00, 80.0, and 900 ng/mL were from 100.2% to 102.5%. Pharmacokinetic parameters of stavudine reference formulation were obtained as follows: Tmax was 0.6±0.2 h, Cmax was 480.7±150.9 g/L, t1/2 was 1.7±0.4 h, and AUC0-t was 872.8±227.8 g·h/L, and pharmacokinetic parameters of stavudine test formulation were obtained as follows: Tmax was 0.5±0.2 h, Cmax was 537.5±178.5 g/L, t1/2 was 1.7±0.3 h, and AUC0-t was (914.1±284.5 g·h/L. Calculated with AUC0-t, the bioavailability of two formulations was 105.0%.

  18. 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

  19. 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.

  20. Extraction-atomic-absorption determination of vanadium in salt liquors

    An extraction-atomic-absorption method to determine 0.1-0.8 mg/l vanadium in salt liquors containing 300 g/l NaCl is developed. To separate the basis extraction concentrating with hydroxyquinoline solution in chloroform with subsequent reextraction of vanadium at pH 9.4 is used. Results of vanadium determination in the salt liquer are as follows: vanadium determined x=0.22 mg/l, n=10, ssub(x)=0.045 mg/l, confidence range (at α=0.95)-(0.22+-0.03) mg/l, relative standard deviation is 0.20

  1. Instrumental modification intended to save time, and volumes of sample and reagent solutions, in the atomic fluorescence spectrometric determination of mercury.

    Pérez-Sirvent, Carmen; Martínez-Sánchez, María J; García-Lorenzo, Mariluz; López-García, Ignacio; Hernández-Córdoba, Manuel

    2007-05-01

    Use of small membrane pumps, instead of peristaltic pumps, to introduce sample and reagent solutions into the spectrometer has several advantages in atomic fluorescence spectrometric determination of mercury. This simple modification results in a substantial saving in the time required for the measurements and so 90% of reagent solution volumes and 95% of sample solution volumes are saved, with a consequent decrease in the volume of waste generated. The sampling frequency is almost tripled, with no deterioration in sensitivity, which is similar to that obtained by use of peristaltic pumps. The relative standard deviation for ten consecutive measurements of a 1 microg L-1 mercury solution was approximately 2%. PMID:17351707

  2. Determination of burnup balance for nuclear reactor fuel on the basis of γ-spectrometric determination of fission products

    Results are given of experimental investigations in one of the versions of the method for determination of the balance of nuclear fuel burnup process by means of the γ-spectrometry of fission products. In the version being considered a balance of the burnup process was determined on the base of 106Ru, 134Cs.Activity was measured by means of a γ-spectrometer with Ge counter. Investigations were done on the natural uranium metal fuel from the heavy-water moderated reactor of the first Czechoslovakian nuclear power plant A1 in Yaslovske Bohunice. Possibility was checked of determination of the fuel burnup depth as well as of the isotope ratio and content of plutonium. Results were compared with the control data which had been obtained on the base of the mass-spectrometry of U, Pu and Nd. The reasors for deviations were estimated in the cases when they were greater tan error in the control data

  3. 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)

  4. Atomic absorption determination of yttrium in matallurgic materials

    Atomic absorption spectroscopy techniques have been developed for Y determination in Mg-, Cr-, Ni-, Ti base alloys. The lower limit of Y determination is 0.01%. The Sr amount equals 0.07 and 0.035 for the 0.01-0.1 and 0.1-1.0 mas.% ranges of Y concentration, respectively. The presence in solution of 0.5-5 M HCl, H2SO4 and HNO3 as well as of up to 1 mg/ml Fe, Co, Zr, Ce, Sn, Zn, Cu, Mo doesn't affect the analysis results

  5. High-Performance Liquid Chromatographic-Tandem Mass Spectrometric Determination of Itraconazole in Human Plasma for Bioavailability and Bioequivalence Studies

    Choi, Young Wook; Nam, Dae Young; Kang, Kyoung Hoon; Ha, Kyung Wook; Han, In Hee; Chang, Byung Kon; Yoon, Mi Kyeong; Lee, Jae Hwi [Chung-Ang University, Seoul (Korea, Republic of)

    2006-02-15

    A highly sensitive high-performance liquid chromatographic-tandem mass spectrometric method (HPLC-MSMS) has been developed to quantify itraconazole in human plasma for the purpose of pharmacokinetic studies. Sample preparation was carried out by liquid-liquid extraction using loratadine as an internal standard. Chromatographic separation used a YMC C{sub 18} column, giving an extremely fast total run time of 3 min. The method was validated and used for the bioequivalence study of itraconazole tablets in healthy male volunteers (n = 31). The lower limit of detection proved to be 0.2 ng /mL for itraconazole.

  6. High-Performance Liquid Chromatographic-Tandem Mass Spectrometric Determination of Itraconazole in Human Plasma for Bioavailability and Bioequivalence Studies

    A highly sensitive high-performance liquid chromatographic-tandem mass spectrometric method (HPLC-MSMS) has been developed to quantify itraconazole in human plasma for the purpose of pharmacokinetic studies. Sample preparation was carried out by liquid-liquid extraction using loratadine as an internal standard. Chromatographic separation used a YMC C18 column, giving an extremely fast total run time of 3 min. The method was validated and used for the bioequivalence study of itraconazole tablets in healthy male volunteers (n = 31). The lower limit of detection proved to be 0.2 ng /mL for itraconazole

  7. 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)

  8. Validation of a method to the addition the multiple standard in the analysis of Pb in reservoir waters for atomic absorption spectrometric

    The evaluation of a method is presented for the analysis of Pb in reservoir waters for atomic spectrometric with direct aspiration. For the validation of the analytic method a level of concentration of 0.05 mg/L was evaluated. The precision of the method was of 9.97% and the bias was 0.6% 8 samples of surface waters they were collected and of bottom of the tributaries of the reservoir Scorpions and the stocking of the concentrations in the tributaries was from 0,052 +- 0.026 inferior mg/L to the established one in the Cuban norm of evaluation of the hydirc objects of fishing use

  9. Determination of the Mean HI Absorption of the Intergalactic Medium

    A. Aghaee; P. Petitjean; R. Srianand; C. S. Stalin; R. Guimarães

    2010-06-01

    In recent years, the Lyman- forest in quasar spectra has been used, together with -body simulations, to determine the underlying matter distribution in the intergalactic medium (IGM). One of the key parameters to be known in order to compare observations and numerical simulations is the mean HI absorption in the IGM. To derive the latter, one has first to fit the quasar continuum.We have observed 20 high redshift and highly luminous QSOs (V ≤ 17.5 and 2.40 ≤ em ≤ 3.91) at intermediate spectral resolution, with either EMMI (ESO Multi-Mode Instrument) on the ESO-NTT telescope or CARELEC at the OHP (Observatoire de Haute-Provence), and applied different methods of determining the QSO continuum to this QSO sample. We have measured the amount of absorption, known as the flux decrement, , in the Lyman- forest for these different methods and compared the results. In addition, we have compared values measured along the same lines of sight observed at high and intermediate spectral resolutions.We discuss the systematics resulting from the use of automatic continuum fitting methods.

  10. Ultrasound-assisted ionic liquid dispersive liquid-liquid microextraction combined with graphite furnace atomic absorption spectrometric for selenium speciation in foods and beverages.

    Tuzen, Mustafa; Pekiner, Ozlem Zeynep

    2015-12-01

    A rapid and environmentally friendly ultrasound assisted ionic liquid dispersive liquid liquid microextraction (USA-IL-DLLME) was developed for the speciation of inorganic selenium in beverages and total selenium in food samples by using graphite furnace atomic absorption spectrometry. Some analytical parameters including pH, amount of complexing agent, extraction time, volume of ionic liquid, sample volume, etc. were optimized. Matrix effects were also investigated. Enhancement factor (EF) and limit of detection (LOD) for Se(IV) were found to be 150 and 12 ng L(-1), respectively. The relative standard deviation (RSD) was found 4.2%. The accuracy of the method was confirmed with analysis of LGC 6010 Hard drinking water and NIST SRM 1573a Tomato leaves standard reference materials. Optimized method was applied to ice tea, soda and mineral water for the speciation of Se(IV) and Se(VI) and some food samples including beer, cow's milk, red wine, mixed fruit juice, date, apple, orange, grapefruit, egg and honey for the determination of total selenium. PMID:26041239

  11. Generation of volatile copper species after in situ ionic liquid formation dispersive liquid-liquid microextraction prior to atomic absorption spectrometric detection.

    Stanisz, Ewa; Zgoła-Grześkowiak, Agnieszka; Matusiewicz, Henryk

    2014-11-01

    The new procedure using in situ synthesis of ionic liquid extractant for dispersive liquid-liquid microextraction (in situ IL DLLME) combined with generation of volatile species prior to electrothermal atomic absorption spectrometry (ET AAS) for the determination of copper in soil samples was developed. Analytical signals were obtained without the back-extraction of copper from the IL phase prior to its determination. Under optimal conditions, the extraction in 10 mL of sample solution employing 8 μL of 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (HmimNTf2) (as the extraction solvent) was conducted. The ionic liquid served as two-task reagent: the efficient extractant and enhancement substance for generation step. The chemical generation of volatile species was performed by reduction of acidified copper solution (HCl 0.8 mol L(-1)) with NaBH4 (1.5%). Some essential parameters of the chemical generation such as NaBH4 and HCl concentrations, the kind and concentration of ionic liquid, carrier gas (Ar) flow rate, reaction and trapping time as well as pyrolysis and atomization temperatures were studied. For photogeneration the effect of the parameters such as the kind and concentration of low molecular weight organic acids and ionic liquid, carrier gas (Ar) flow rate, UV irradiation and ultrasonication time on the analytical signals were studied. The detection limit was found as 1.8 ng mL(-1) and the relative standard deviation (RSD) for seven replicate measurements of 100 µg mL(-1) in sample solution was 7%. The accuracy of the proposed method was evaluated by analysis of the certified reference materials. The measured copper contents in the reference materials were in satisfactory agreement with the certified values. The method was successfully applied to analysis of the soil and sediment samples. PMID:25127592

  12. Determining photon energy absorption parameters for different soil samples.

    Kucuk, Nil; Tumsavas, Zeynal; Cakir, Merve

    2013-05-01

    The mass attenuation coefficients (μs) for five different soil samples were measured at 661.6, 1173.2 and 1332.5 keV photon energies. The soil samples were separately irradiated with (137)Cs and (60)Co (370 kBq) radioactive point gamma sources. The measurements were made by performing transmission experiments with a 2″ × 2″ NaI(Tl) scintillation detector, which had an energy resolution of 7% at 0.662 MeV for the gamma-rays from the decay of (137)Cs. The effective atomic numbers (Zeff) and the effective electron densities (Neff) were determined experimentally and theoretically using the obtained μs values for the soil samples. Furthermore, the Zeff and Neff values of the soil samples were computed for the total photon interaction cross-sections using theoretical data over a wide energy region ranging from 1 keV to 15 MeV. The experimental values of the soils were found to be in good agreement with the theoretical values. Sandy loam and sandy clay loam soils demonstrated poor photon energy absorption characteristics. However, clay loam and clay soils had good photon energy absorption characteristics. PMID:23179375

  13. Determination of molybdenum in flotation concentrates by atomic absorption spectrophotometry

    Molybdenum was determined by atomic absorption spectrophotometry in 0.05 N ammoniacal solution after the decomposition of the concentrate with aqua regia. Negros ore from Philippines was used as a flotation feed, which contained chalcopyrites and calcium-magnesium minerals. Among the metals tested copper, iron and the alkaline earths interfered. Less than 50 ppm of copper yielded lower results for molybdenum. Higher results came out with more than 50 ppm of copper. In the presence of iron and citric acid (0.4 g/100 ml) which is a suppressor for hydroxide formation, a lower estimation resulted for molybdenum. Calcium interfered, lower results by 2 and >10% being obtained with respective 2.5 and 20 ppm of calcium. More than 20 ppm of magnesium behaved similarly. Sodium sulfate (0.5 g/100 ml) served as the suppressor for copper, iron and citric acid; 100 ppm each of copper and iron did not interfere in this way. Interferences due to calcium and magnesium (less than 60 ppm) was able to be masked by the addition of sodium silicate (200 ppm as silica). The analysis of flotation products and synthetic samples consisting of molybdenite, chalcopyrite, calcium chloride and magnesium sulfate revealed that the atomic absorption method can be applied to the analysis of the concentrates for molybdenum with an error of about 2%. (auth.)

  14. Precise determination of magnesium and lutetium in input accountability tank solutions of nuclear reprocessing plants by the mass spectrometric stable isotope dilution technique

    This paper describes the procedures for the determination of Mg and Lu concentrations in input solutions of nuclear fuel dissolved in reprocessing plants. The main aim of this work is to supply an independent method for measuring the volume of input accountability tanks. The methods used include suitable radiochemical separations and isotope dilution mass spectrometric measurements. Chemical separations from highly radioactive solutions have been tested in order to obtain pure and ''cold'' samples of Mg and Lu to be measured by Mass Spectrometry. Different ionisation techniques have been used in obtaining precise isotopic ratios. Results are presented and compared with historical data. A critical evaluation of methods, results and apparatus is given. 17 refs

  15. The fuel burn-up determination by combined passive neutron and gamma - spectrometric ND - measurements. Final report for the period 1 July 1980 - 30 April 1988

    The non-destructive gamma-spectrometric method (HRGS) and the passive neutron technique (PNT) were applied to the determination of WWER 440 reactor spent fuel assemblies burn-up for safeguard purposes. Rapid codes FISPR-2 and BUNECO were compiled on HP-85 and OLIVETTI M24 computers for the IAEA inspectors. An improved equipment was constructed and tested for the fixation of the ''fork detector''. Measurements were carried-out at 1st unit of NPP Bohunice. The correlation between burn-up and fission product ratio 134Cs/137Cs or neutron count rate were analysed. Correlations between concentrations 235U, Pu and burn-up were analysed as well. A simplified procedure for assemblies burn-up check by PNT was proposed for the inspectors. Refs, figs and tabs

  16. Determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using radiochemical separation combined with radiometric and mass spectrometric measurements

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin;

    2014-01-01

    This paper reports an analytical method for the determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using anion exchange chromatography in combination with extraction chromatography for chemical separation of Pu. Both radiometric methods (liquid scintillation...... counting and alpha spectrometry) and inductively coupled plasma mass spectrometry (ICP-MS) were applied for the measurement of plutonium isotopes. The decontamination factors for uranium were significantly improved up to 7.5×105 for 20 g soil compared to the level reported in the literature......, this is critical for the measurement of plutonium isotopes using mass spectrometric technique. Although the chemical yield of Pu in the entire procedure is about 55%, the analytical results of IAEA soil 6 and IAEA-367 in this work are in a good agreement with the values reported in the literature or reference...

  17. Mass spectrometric immunoassay

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2007-12-04

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

  18. 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

  19. 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

  20. Atomic absorption spectroscopic, conductometric and colorimetric methods for determination of fluoroquinolone antibiotics using ammonium reineckate ion-pair complex formation

    Ragab, Gamal H.; Amin, Alaa S.

    2004-03-01

    Three accurate, rapid and simple atomic absorption spectrometric, conductometric and colorimetric methods were developed for the determination of norfloxacin (NRF), ciprofloxacin (CIP), ofloxacin (OFL) and enrofloxacin (ENF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in acetone. The pink coloured complexes were determined either by AAS or colorimetrically at λmax 525 nm directly using the dissolved complex. Using conductometric titration, the studied drugs could be evaluated in 50% (v/v) acetone in the range 5.0-65, 4.0-48, 5.0-56 and 6.0-72 μg ml -1 of NRF, CPF, OFL and ENF, respectively. The optimizations of various experimental conditions were described. The results obtained showed good recoveries of 99.15±1.15, 99.30±1.40, 99.60±1.50, and 99.00±1.25% with relative standard deviations of 0.81, 1.06, 0.97, and 0.69% for NRF, CPF, OFL, and ENF, respectively. Applications of the proposed methods to representative pharmaceutical formulations are successfully presented.

  1. Simultaneous Preconcentration of Copper, Nickel, Cobalt and Lead Ions Prior to Their Flame Atomic Absorption Spectrometric Determination

    A sensitive and simple method for the simultaneous preconcentration of nutritionally important minerals in real samples has been reported. The method is based on the adsorption of Cu2+, Ni2+, Co2+ and Pb2+ on 4-propyl-2-thiouracil (PUT) loaded on activated carbon. The metals on the complexes are eluted using 5 mL 3 M HNO3 in acetone. The influences of the analytical parameters including pH and sample volume were investigated. The effects of matrix ions on the retentions of the analytes were also examined. The recoveries of analytes were generally higher than 95 %. The detection limits for Cu2+, Ni2+, Co2+ and Pb2+ were 1.6, 1.3, 1.2, 2.3 ng ml-1, respectively. The method has been successfully applied for these metals content evaluation in some real samples including natural water samples

  2. Uranium determination in zirconium

    The method used for the spectrometric uranium determination with 2-(2-thiolase)-5-diethylaminophenol was modified for its application in the zirconium samples analysis with an uranium content of the 0.1% order. The samples, previously dissolved in nitric acid, were submitted to a separative stage of liquid-liquid extraction, with a trioctylphosphine (TOPO) oxide diluted in cyclohexane. A sodium fluoride aqueous solution was necessary to be aggregated in the spectrometric determination so as to complex the zirconium vestiges, which could be present, originated by the Zr/U high relation of the initial sample. Under the established working conditions, different spectrometric assays, dyes absorption spectra and its uranium complex, complex stability, PH influence determination of the dyes-uranium relation, calculation of the complex's apparent formation constant and its molar absorption, were performed. (Author)

  3. Spectrometric techniques 4

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume IV discusses three widely diversified areas of spectrometric techniques. The book focuses on three spectrometric methods. Chapter 1 discusses the phenomenology and applications of Coherent Anti-Stokes Raman Spectroscopy (CARS), the most commonly used optical technique that exploit the Raman effect. The second chapter is concerned with diffraction gratings and mountings for the Vacuum Ultraviolet Spectral Region. Chapter 3 accounts the uses of mass spectrometry, detectors, types of spectrometers, and ion sources. Physicists and chemists will find the book a go

  4. Luminescence and optical absorption determination in porous silicon

    Nogal, U.; Calderon, A.; Marin, E.; Rojas T, J. B.; Juarez, A. G., E-mail: u_nogal@hotmail.com [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Calz. Legaria No. 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico)

    2012-10-15

    We applied the photoacoustic spectroscopy technique in order to obtain the optical absorption spectrum in porous silicon samples prepared by electrochemical anodic etching on n-type, phosphorous doped, (100)-oriented crystal-line silicon wafer with thickness of 300 {mu}m and 1-5 {omega}cm resistivity. The porous layers were prepared with etching times of 13, 20, 30, 40 and 60 minutes. Also, we realized a comparison among the optical absorption spectrum with the photoluminescence and photo reflectance ones, both obtained at room temperature. Our results show that the absorption spectrum of the samples of porous silicon depends notably of the etching time an it consist of two distinguishable absorption bands, one in the Vis region and the other one in the UV region. (Author)

  5. Optimization of spectrometric gamma-gamma probe configuration using very low radioactivity sources for lead and zinc grade determination in borehole logging

    The suitability of spectrometric backscattered gamma - gamma well logging measurements to predict lead and zinc metal equivalent content is demonstrated. A centralised tool employing a gamma - ray source of very low radioactivity (1.8 MBq) is used. The logging tools is tested using 133 Ba and 137 Cs sources with a 37 mm (diameter) x 750 mm NaI (TI) scintillation detector. Five source - to - detector configurations were analysed for 18 geophysical models, 13 of which had a borehole diameter of 130 mm and the other 5 had a borehole diameter of 160 mm. Regression analysis on the laboratory logging data for each configuration in order to establish the calibration equation for a lead (Pb) and zinc metal equivalent (ZME) prediction is carried out. The optimum configuration for the logging probe using a 133 Ba source was determined to be 52 mm source - to - detector spacing. This configuration gives the best results for both Pb and ZME grade. The r.m.s deviations for Pb and ZME were 0.33 and 2.3%, respectively. The optimum configuration for the logging probe using a 137 Cs source was determined to be 64 mm source - to - detector spacing. This configuration gives the best results for both Pb and ZME grade. The r.m.s deviations for Pb and ZME were 0.36 and 2.2%, respectively. (author)

  6. Optimisation of spectrometric gamma-gamma probe configuration using very low radioactivity sources for lead and zinc grade determination in borehole logging

    The suitability of spectrometric backscattered gamma-gamma well logging measurements to predict lead and zinc metal equivalent content is demonstrated. A centralised tool employing a gamma-ray source of very low radioactivity (1.8 MBq) is used. The logging tool is tested using 133Ba and 137Cs sources with a 37 mm (diameter)x75 mm NaI (TI) scintillation detector. Five source-to-detector configurations were analysed for 18 geophysical models, 13 of which had a borehole diameter of 130 mm and the other 5 had a borehole diameter of 160 mm. Regression analysis on the laboratory logging data for each configuration in order to establish the calibration equation for a lead (Pb) and zinc metal equivalent (ZME) prediction is carried out. The optimum configuration for the logging probe using a 133Ba source was determined to be 52 mm source-to-detector spacing. This configuration gives the best results for both Pb and ZME grade. The rms deviations for Pb and ZME were 0.33 and 2.3%, respectively. The optimum configuration for the logging probe using a 137Cs source was determined to be 64 mm source-to-detector spacing. This configuration gives the best results for both Pb and ZME grade. The rms deviations for Pb and ZME were 0. 3 6 and 2.2 %, respectively

  7. Evaluation of mass spectrometric data using principal component analysis for determination of the effects of organic lakes on protein binder identification.

    Hrdlickova Kuckova, Stepanka; Rambouskova, Gabriela; Hynek, Radovan; Cejnar, Pavel; Oltrogge, Doris; Fuchs, Robert

    2015-11-01

    Matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry is commonly used for the identification of proteinaceous binders and their mixtures in artworks. The determination of protein binders is based on a comparison between the m/z values of tryptic peptides in the unknown sample and a reference one (egg, casein, animal glues etc.), but this method has greater potential to study changes due to ageing and the influence of organic/inorganic components on protein identification. However, it is necessary to then carry out statistical evaluation on the obtained data. Before now, it has been complicated to routinely convert the mass spectrometric data into a statistical programme, to extract and match the appropriate peaks. Only several 'homemade' computer programmes without user-friendly interfaces are available for these purposes. In this paper, we would like to present our completely new, publically available, non-commercial software, ms-alone and multiMS-toolbox, for principal component analyses of MALDI-TOF MS data for R software, and their application to the study of the influence of heterogeneous matrices (organic lakes) for protein identification. Using this new software, we determined the main factors that influence the protein analyses of artificially aged model mixtures of organic lakes and fish glue, prepared according to historical recipes that were used for book illumination, using MALDI-TOF peptide mass mapping. PMID:26505772

  8. Recent developments in automated determinations of trace level concentrations of elements and on-line fractionations schemes exploiting the micro-sequential injection - lab-on-valve approach

    Hansen, Elo Harald; Miró, Manuel; Long, Xiangbao;

    2006-01-01

    The determination of trace level concentrations of elements, such as metal species, in complex matrices by atomic absorption or emission spectrometric methods often require appropriate pretreatments comprising separation of the analyte from interfering constituents and analyte preconcentration...

  9. A liquid chromatography-atmospheric pressure photoionization tandem mass spectrometric method for the determination of organosulfur compounds in petroleum asphalt cements.

    da Silveira, Géssica Domingos; Faccin, Henrique; Claussen, Luis; Goularte, Rayane Bueno; Do Nascimento, Paulo C; Bohrer, Denise; Cravo, Margareth; Leite, Leni F M; de Carvalho, Leandro Machado

    2016-07-29

    We present a sensitive liquid chromatography-atmospheric pressure photoionization tandem mass spectrometric (UHPLC-APPI-MS/MS) method for the determination of selected organosulfur compounds in Brazilian asphalt cements. It was possible to detect 14 organosulfur compounds of different classes where sulfoxides and sulfones presented higher sensibility in ionization than thiophenes and aromatic sulfides. A dopant-assisted APPI method was also tested, however, when chromatographic flow rate was optimized a decrease in signal was observed for all compounds. PAHs were tested and ruled out as possible interfering compounds and the matrix effect of asphalt cements was within an acceptable range for the quantification of organosulfur compounds. The proposed method was found to have satisfactory linearity and accuracy with recoveries between 83.85 and 110.28% for thianaphthene and 3-methylbenzothiophene, respectively. Therefore, the method allowed the characterization of organosulfur compounds in Brazilian asphalt cements and demonstrated changes in the amount quantified in asphaltenic and maltenic fractions after the RTFOT+SUNTEST aging process. PMID:27342135

  10. Qualification and application of a liquid chromatography-quadrupole time-of-flight mass spectrometric method for the determination of trastuzumab in rat plasma.

    Park, Min-Ho; Lee, Min-Woo; Shin, Young G

    2016-04-01

    An liquid chromatography-quadrupole time-of-flight (QqTOF) mass spectrometric method was developed for the determination of humanized or human monoclonal antibodies in rat plasma at the early drug discovery stage. Trastuzumab was used as a model monoclonal antibody. The method consisted of immunoprecipitation followed by tryptic digestion for sample preparation and LC-TOF-MS/MS analysis of specific signature peptides in the positive ion mode using electrospray ionization for analysis. A stable isotope-labeled signature peptide was also used as internal standard. A quadratic regression (weighted 1/concentration(2) ), with an equation y = ax(2)  + bx + c, was used to fit calibration curves over the concentration range of 0.500-100 µg/mL for trastuzumab. Samples from a pharmacokinetic study in rat were analyzed by this qualified LC-TOF-MS/MS method and concentrations were compared with those generated by enzyme linked immunosorbent assays method. The LC-TOF-MS/MS method was accurate and precise, with quantitative results comparable with those of ELISA. The qualification run met the acceptance criteria of ±25% accuracy and precision values for quality control samples. Within-run accuracy ranged from 1.53 to 9.20% with precision values ≤10.29%. This LC-TOF-MS/MS method approach could be used as a complementary method for humanized or human monoclonal antibodies at the early drug discovery stage. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26317190

  11. Liquid chromatography-tandem mass spectrometric methods for the determination of spinosad, thiacloprid and pyridalyl in spring onions and estimation of their pre-harvest interval values.

    Dasenaki, Marilena E; Bletsou, Anna A; Hanafi, Ahmad H; Thomaidis, Nikolaos S

    2016-12-15

    Two liquid chromatography-tandem mass spectrometric methods were developed and validated to determine spinosyn A and D, thiacloprid and pyridalyl in spring onions cultivated under Egyptian field conditions. The degradation rates, the pre-harvest interval (PHI) values and the half-life values of the three pesticides were estimated. QuEChERS was used for sample preparation and the separation was performed on an X-Bridge C18 column with ACN-formic acid 0.1% as the mobile phase. Linear range, method detection limits (MDLs), precision, recovery and matrix effects were estimated. The multi-residue MDLs ranged from 0.02μg/kg (spinosyn A & D) to 0.05μg/kg for pyridalyl. All the investigated pesticides showed high degradation rates. For spinosad the half-life value was 1.2days, for thiacloprid it reached 2.2days and for pyridalyl 4.4days. Furthermore, the calculated PHI values, according to the maximum residue levels set by the EU, were 0days for spinosad, 9.8days for thiacloprid and 39.4days for pyridalyl. PMID:27451196

  12. Optimisation of spectrometric gamma-gamma probe configuration using very low radioactivity sources for lead and zinc grade determination in borehole logging

    Asfahani, J

    1999-01-01

    The suitability of spectrometric backscattered gamma-gamma well logging measurements to predict lead and zinc metal equivalent content is demonstrated. A centralised tool employing a gamma-ray source of very low radioactivity (1.8 MBq) is used. The logging tool is tested using sup 1 sup 3 sup 3 Ba and sup 1 sup 3 sup 7 Cs sources with a 37 mm (diameter)x75 mm NaI (TI) scintillation detector. Five source-to-detector configurations were analysed for 18 geophysical models, 13 of which had a borehole diameter of 130 mm and the other 5 had a borehole diameter of 160 mm. Regression analysis on the laboratory logging data for each configuration in order to establish the calibration equation for a lead (Pb) and zinc metal equivalent (ZME) prediction is carried out. The optimum configuration for the logging probe using a sup 1 sup 3 sup 3 Ba source was determined to be 52 mm source-to-detector spacing. This configuration gives the best results for both Pb and ZME grade. The rms deviations for Pb and ZME were 0.33 and ...

  13. [Determination of nine estrogenic steroids in milk using matrix solid phase dispersion-ultra performance liquid chromatography with mass spectrometric detector].

    Liu, Hongcheng; Li, Ning; Lin, Tao; Shao, Jinliang; Li, Qiwan

    2015-11-01

    An analytical method for the multiresidue determination of nine estrogenic steroids in milk was developed by modified matrix solid phase dispersion (MSPD) purification and ultra performance liquid chromatography (UPLC) with mass spectrometric detector (MSD). The sensitivity and accuracy of MSD were better than that of ultraviolet detector. In comparison with traditional mass spectrometry, the merits of MSD were simpler in operation and shorter in starting time (5 min). The results showed that the limits of detection of the compounds with nucleophilic substitution were high in positive ion mode of MSD and were easily affected by environmental conditions. The matrix effects of milk samples reduced from 84%-160% to 80%-121% after MSPD purification. The intraday precision and interday precision of the nine estrogenic steroids were 0.87%-1.78% and 1.82%-3.79%, respectively. The average recoveries were 68.7%-94.7%, and the relative standard deviations (RSDs) were less than 10%. The limits of detection (LODs) were 0.5-10 μg/kg. The limits of quantification (LOQ) were 2-20 μg/kg. PMID:26939362

  14. Influence of particle size of wear metal on the spectrometric oil analysis programme (SOAP), demonstrated by the determination of iron by AAS

    The possibility that there might be a relation between particle size of wear metal and spectrometric determination, (e.g. of the iron content in used lubricating oils) has been examined. In this connection it had to be clarified from which particle size of the iron wear the Fe content determined by direct AAS (solution of the oil sample) is in agreement with the true value in the used oil. The determination of the absolute iron content was performed by a colorimetric method preceded by an incineration of the used oil. Contrary to other publications, in which work is based on spherical iron particles as a simulated wear, the test described here relates to true wear particles. To obtain the total iron wear from a gear oil it was filtered off from the used oil and afterwards separated into defined particle size ranges by a procedure specially developed for this purpose. The different groups of scaly particles, which were collected in this way, were then mixed homogeneously into fresh luboil samples according to their sizes. The determination of the iron content from these newly mixed luboil samples was carried out 1. by direct AAS, 2. by AAS after incineration of the oil samples and 3. by a colorimetric method (to obtain the absolute value of the iron content). The results showed a recovery of the iron of only 50% if the wear particles were bigger than about 2 μm. That means that the true value of the iron content in a used lubricating oil is found by direct AAS only if the particle size is <=1 μm. (orig.)

  15. Determining the Fraction of Intrinsic CIV Absorption in Quasi-Stellar Object Absorption Line Systems

    Richards, G T; Yanny, B; Kollgaard, R I; Laurent-Mühleisen, S A; Vanden Berk, Daniel E; Richards, Gordon T.; York, Donald G.; Yanny, Brian; Kollgaard, Ronald I.; Berk, Daniel E. Vanden

    1999-01-01

    We present the results of a study of QSO Absorption Line Systems (QSOALSs) with respect to intrinsic QSO properties using an updated catalog of data in the literature. We have searched the literature for 6 and 20 cm radio flux densities and have studied 20 cm maps from the FIRST VLA Survey in order to compare the absorption properties with radio luminosity, radio spectral index and radio morphology. This work focuses particularly on the nature of CIV QSOALSs and their distribution in velocity space in light of intrinsic QSO properties. We find that the distribution of narrow, CIV absorption systems with relative velocities exceeding 5000 km/s is dependent not only on the optical luminosity of the QSOs, but also on the radio luminosity, the radio spectral index and the radio morphology of the QSOs. These observations are apparently inconsistent with the hypothesis that these systems are entirely due to intervening galaxies and it would seem that the contamination of the intervening systems (from 5000 to 75000 ...

  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. A high-performance liquid chromatographic-atmospheric pressure chemical ionization-tandem mass spectrometric method for determination of risperidone and 9-hydroxyrisperidone in human plasma.

    Moody, David E; Laycock, John D; Huang, Wei; Foltz, Rodger L

    2004-09-01

    Risperidone, a benzisoxazole derivative, is an antipsychotic agent used for the treatment of schizophrenia. We developed a liquid chromatographic-atmospheric pressure chemical ionization-tandem mass spectrometric (LC-APCI-MS-MS) method with improved sensitivity, selectivity, and dynamic range for determination of risperidone and 9-hydroxyrisperidone in human plasma. A structural analogue of risperidone, RO68808 (5 ng/mL), is added as the internal standard to 1 mL of human plasma. Plasma is made basic, extracted with pentane/methylene chloride (3:1), the organic phase evaporated to dryness, and the residue is reconstituted in water with 0.1% formic acid/acetonitrile (20:1). For LC-MS-MS analysis, a Metachem Inertsel HPLC column (2.1 x 150 mm, 5-microm particle size) is connected to a Finnigan TSQ7000 tandem MS via the Finnigan API interface. Both electrospray (ESI) and APCI produced predominantly MH(+) ions for the two analytes and the internal standard. Ions detected by selected reaction monitoring correspond to the following transitions: m/z 411 to 191 for risperidone, m/z 427 to 207 for 9-hydroxyrisperidone, and m/z 421 to 201 for the internal standard. APCI provided a larger dynamic range (0.1 to 25 ng/mL) and better precision and accuracy than ESI. Intrarun accuracy and precision determined at 0.1, 0.25, 2.5, and 15 ng/mL were within 12% of target with %CVs not exceeding 10.9%. Interrun accuracy and precision determined at the same concentrations were within 9.6% of target with %CVs not exceeding 6.7%. Analytes were stable in plasma after 24 h at room temperature, 2 freeze-thaw cycles, and 490 days at -20 degrees C. PMID:15516302

  18. Mechanistic Determinants of Biotherapeutics Absorption Following SC Administration

    Richter, Wolfgang F; Bhansali, Suraj G.; Morris, Marilyn E.

    2012-01-01

    The subcutaneous (SC) route is of growing interest for the administration of biotherapeutics. Key products on the biotherapeutic market such as insulins, but also several immunoglobulins or Fc-fusion proteins, are administered SC. Despite the importance of the SC route, the available knowledge about the processes involved in the SC absorption of biotherapeutics is limited. This review summarizes available information on the physiology of the SC tissue and on the pharmacokinetic processes afte...

  19. Pathlength Determination for Gas in Scattering Media Absorption Spectroscopy

    Liang Mei

    2014-02-01

    Full Text Available Gas in scattering media absorption spectroscopy (GASMAS has been extensively studied and applied during recent years in, e.g., food packaging, human sinus monitoring, gas diffusion studies, and pharmaceutical tablet characterization. The focus has been on the evaluation of the gas absorption pathlength in porous media, which a priori is unknown due to heavy light scattering. In this paper, three different approaches are summarized. One possibility is to simultaneously monitor another gas with known concentration (e.g., water vapor, the pathlength of which can then be obtained and used for the target gas (e.g., oxygen to retrieve its concentration. The second approach is to measure the mean optical pathlength or physical pathlength with other methods, including time-of-flight spectroscopy, frequency-modulated light scattering interferometry and the frequency domain photon migration method. By utilizing these methods, an average concentration can be obtained and the porosities of the material are studied. The last method retrieves the gas concentration without knowing its pathlength by analyzing the gas absorption line shape, which depends upon the concentration of buffer gases due to intermolecular collisions. The pathlength enhancement effect due to multiple scattering enables also the use of porous media as multipass gas cells for trace gas monitoring. All these efforts open up a multitude of different applications for the GASMAS technique.

  20. New approaches for the mass spectrometric determination of trace concentrations and congener group patterns of chlorinated paraffins in biota

    Reth, Margot

    2006-01-01

    The determination of chlorinated paraffins (CPs) in the environment is important, since CPs are persistent, bioaccumulative and toxic. However, the analysis of these complex mixtures containing thousands of isomers is also a demanding task. CP analysis and especially the quantification of CPs are far from being well established. In this work, new methodologies were developed for the determination of CPs in biota by low-resolution mass spectrometry (LRMS). The use of expensiv...

  1. 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)

  2. FTIR-spectrometer-determined absorption coefficients of seven hydrazine fuel gases - Implications for laser remote sensing

    Molina, L. T.; Grant, W. B.

    1984-01-01

    The absorption spectra of three hydrazines and four of their air-oxidation products were measured in the 9-12-micron spectral region with a Fourier transform infrared (FTIR) spectrometer with a 0.05-kayser resolution to determine absorption coefficients at CO2 and tunable diode laser wavelengths. The measurements agreed well with published CO2 laser determinations for many of the absorption coefficients, except where the published values are thought to be in error. The coefficients were then used to estimate the sensitivity for remote detection of these gases using CO2 and tunable diode lasers in long-path differential absorption measurements.

  3. Preconcentration of submicrogram amounts of metals from natural water for X-ray energy spectrometric determination using pyrrolidinecarbodithioic acid

    A method was developed for the routine determination of several trace metals in natural waters by X-ray energy spectrometry following precipitation with pyrrolidinecarbodithioate. Preoxidation with persulfate eliminates interferences by organic matter. By optimizing carrier ion selection and measurement conditions, one may determine dithioate-reactive elements with Z less than or equal to 50 by means of their K X-rays, and some with Z greater than or equal to 80 by means of their L X-rays. Determinations are feasible for several elements at concentrations down to 250 ng L-1, or below. Recoveries are generally greater than 90%, although some exceptions are noted. Reproducibility with real samples averaged about 25% relative standard deviation for five representative elements at concentrations above 250 ng L-1. 24 references, 5 figures, 4 tables

  4. Determining neutrino absorption spectra at Ultra-High Energies

    Scholten, Olaf; Van Vliet, Arjen

    2008-01-01

    A very efficient method to measure the flux of Ultra-high energy (UHE) neutrinos is through the detection of radio waves which are emitted by the particle shower in the lunar regolith. The highest acceptance is reached for radio waves in the frequency band of 100-200 MHz which can be measured with modern radio telescopes. In this work we investigate the sensitivity of this detection method to structures in the UHE neutrino spectrum caused by their absorption on the low-energy relic anti-neutr...

  5. Optimization of the preconcentration system of cadmium with 1(2-thiazolylazo)-p-cresol using a knotted reactor and flame atomic absorption spectrometric detection

    The present paper proposes an on-line preconcentration procedure for cadmium determination in drinking water samples. It is based on the precipitation of cadmium(II) ions on a knotted reactor (KR) using 1(2-thiazolylazo)-p-cresol (TAC) as complexing reagent. The optimization step was performed using a full factorial design involving the variables: pH, eluent concentration (nitric acid) and TAC concentration. The results of this experiment demonstrated that these variables at chosen levels are not statistically significant. Under optimized experimental established conditions, analytical parameters for the preconcentration method were: a detection limit of 40.0 ng/l, precision as relative standard deviation (RSD) of 1.2 and 1.0%, for cadmium concentration of 2.5 and 20.0 μg/l, respectively. The preconcentration factor considering the slopes of the analytical curves with and without preconcentration is 23 for a sample volume of 10 ml. This system shows a sampling frequency of 25 h-1. In order to check the accuracy, the standard reference material, NIST SRM 1643d trace elements in water was analyzed. A comparison, using t-test demonstrates that there is not significant difference among the achieved results with proposed method and the certified values. The addition/recovery experiments in the samples analyzed demonstrated the accuracy and applicability of the system developed for cadmium determination in water samples

  6. Spectrometric techniques 3

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume III presents the applications of spectrometric techniques to atmospheric and space studies. This book reviews the spectral data processing and analysis techniques that are of broad applicability.Organized into five chapters, this volume begins with an overview of the instrumentation used for obtaining field data. This text then reviews the contribution that space-borne spectroscopy in the thermal IR has made to the understanding of the planets. Other chapters consider the instruments that have recorded the planetary emission spectra. This book discusses as well

  7. 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.

  8. A novel approach for speciation of airborne chromium by convective-interaction media fast-monolithic chromatography with electrothermal atomic-absorption spectrometric detection.

    Scancar, Janez; Milacic, Radmila

    2002-05-01

    A new analytical procedure using an anion-exchange separation support based on convective-interaction media (CIM) was developed for the speciation of chromium. The separation of Cr(VI) was performed on a weak anion-exchange CIM diethylamine (DEAE) fast-monolithic chromatographic disc. Buffer A (0.005 mol dm(-3) TRIS-HCl, pH 8.0) and buffer B (buffer A plus 3 mol dm(-3) NH4NO3) were employed in the separation procedure. The separated chromium species were determined 'off-line' by ETAAS in 0.5 cm3 fractions. The applicability of the CIM DEAE-ETAAS procedure was investigated for the determination of airborne Cr(VI) at a plasma cutting workplace. Aerosols were collected on polycarbonate membrane filters of 8 and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction of filters in a heated ultrasonic bath was applied to leach chromium. Good repeatability of measurement (+/-3.0%) of the alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.30 microg m(-3) Cr(VI), when 0.25 m3 of air was collected on the filter. The validation of the procedure was performed by spiking filters with Cr(VI) and by the analysis of the standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. Good recoveries for spiked samples (101-102%) and good agreement between Cr(VI) found and the reported certified value for CRM 545 were obtained. The extracts were also analysed by the FPLC-ETAAS technique. Good agreement between two techniques (r2 = 0.9978) confirmed the reliability of the CIM DEAE-ETAAS procedure developed. The main advantage of the procedure lies in the speed of the chromatographic separation (chromatographic run completed in 15 min). PMID:12081040

  9. Determination of nine high-intensity sweeteners in various foods by high-performance liquid chromatography with mass spectrometric detection

    Zygler, Agata; Wasik, Andrzej; Kot-Wasik, Agata; Namieśnik, Jacek

    2011-01-01

    An analytical procedure involving solid-phase extraction (SPE) and high-performance liquid chromatography-mass spectrometry has been developed for the determination of nine high-intensity sweeteners authorised in the EU; acesulfame-K (ACS-K), aspartame (ASP), alitame (ALI), cyclamate (CYC), dulcin (DUL), neohesperidin dihydrochalcone (NHDC), neotame (NEO), saccharin (SAC) and sucralose (SCL) in a variety of food samples (i.e. beverages, dairy and fish products). After extraction with a buffer...

  10. Single-walled carbon nanotubes coated fibers for solid-phase microextraction and gas chromatography-mass spectrometric determination of pesticides in Tea samples.

    Wu, Fang; Lu, Wanping; Chen, Jinghua; Liu, Wei; Zhang, Lan

    2010-08-15

    Using a single-walled carbon nanotubes (SWCNTs) as stationary phase of solid-phase microextraction (SPME) fibers, a simple, low cost and environmentally friendly method for extraction of 13 pesticides in Tea samples has been developed following gas chromatography-mass spectrometric determination. Potential factors affecting the extraction efficiency were investigated and optimized, including extraction and desorption time, extraction temperature, stirring rate, solution pH and ionic strength. Under optimized conditions, the linearity of the developed method was in the range of 0.125-25 ng/mL with correlation coefficients greater than 0.9928 and the limits of detections (LODs) were 0.027-0.23 ng/mL (S/N=3). Meanwhile, the relative standard deviations (RSDs) for five successive measurements with single fiber, fiber-to-fiber, day-to-day were 2.3-13.0, 8.2-14.6 and 4.1-12.5%, respectively, indicating good reproducibility of the proposed method. The fiber had high extraction efficiency for studied pesticides in comparison with commercial poly(dimethylsiloxane) (PDMS) and polyacrylate (PA) fibers and could be used for more than 70 times without decrease of efficiency. The developed method was successfully applied for the analysis of real samples including green Tea, oolong Tea, white Tea, and flower Tea, and the recoveries of the pesticides spiked in these samples ranged from 75.1 to 118.4%. Chlorfenapyr and lambda-cyhalothrin were found in the Tea samples bought randomly from local market. The results demonstrated that the developed SWCNTs-SPME method was a simple, efficient pretreatment and enrichment procedure for pesticides in complex matrices. PMID:20678665

  11. A liquid chromatography-tandem mass spectrometric method for quantitative determination of native 5-methyltetrahydrofolate and its polyglutamyl derivatives in raw vegetables.

    Wang, Chao; Riedl, Ken M; Schwartz, Steven J

    2010-11-01

    Folate deficiency is a prevalent phenomenon worldwide especially in underprivileged countries. Polyglutamyl 5-methyltetrahydrofolate (5MTHF) species are the naturally occurring principle folate in store-bought vegetables. Here we report a simple and complete extraction method for the determination of native polyglutamyl 5-methyltetrahydrofolate in vegetables using high performance liquid chromatography with tandem mass spectrometric detection (HPLC-MS/MS). Coarsely chopped samples (18 different vegetables) were steamed to inactivate glutamylase enzymes and liberate folate from binding proteins and extracted in a reducing buffer with (13)C(5) 5MTHF stable isotope added as internal standard. The polyglutamyl 5-methyltetrahydrofolate species were separated in 9 min on a C(18) column using a reversed phase system. HPLC eluate was interfaced with a triple quadrupole mass spectrometer operated in electrospray positive mode. The respective pseudomolecular cation of each polyglutamyl 5-methyltetrahydrofolate species was selected for fragmentation to a common daughter ion for detection. We quantitated polyglutamyl 5-methyltetrahydrofolate in store-bought vegetables from families Brassicaceae, Asteraceae and Amaranthaceae (including mustard greens, romaine lettuce and Swiss chard) of which most have not been quantitated previously. Most vegetables from Asteraceae and those from Amaranthaceae contained similar amounts of monoglutamyl 5MTHF and polyglutamyl 5MTHF while Brassicaceae were dominated by polyglutamyls and endive species (Asteraceae) contained mainly monoglutamyl 5MTHF. The precision of the method for the various polyglutamyl 5-methyltetrahydrofolate forms was 1-9% RSD, recovery 84-91%, limit of detection 64-658 fmol and limit of quantitation 193-1994 fmol. Herein we describe a rapid, sensitive and selective HPLC-MS/MS technique to quantitate polyglutamyl 5-methyltetrahydrofolate species. This method may be suitable for analyzing the polyglutamyl 5

  12. Development of a high-speed MALDI-triple quadrupole mass spectrometric method for the determination of 3,4-methylenedioxymethamphetamine (MDMA) in oral fluid.

    Poetzsch, Michael; Steuer, Andrea E; Hysek, Cedric M; Liechti, Matthias E; Kraemer, Thomas

    2016-02-01

    3,4-Methylenedioxymethamphetamine (MDMA, ecstasy) is still a widely used illicit designer drug and its detection in different matrices is of major importance for forensic purposes (e.g. driving under the influence) as well as for workplace drug testing or abstinence control. Established analytical methods for the determination of MDMA are mainly employing high performance liquid chromatography (HPLC) or gas chromatography (GC) coupled to mass spectrometric detection. Matrix assisted laser desorption/ionization-triple quadrupole-tandem mass spectrometry (MALDI-QqQ-MS/MS) is so far rarely used in forensics and offers an ultrafast high-throughput platform. The Quantisal™ Oral Fluid Collection Device was used for sample collection. After addition of the deuterated internal standard and a carbonate buffer (0.75 M Na2 CO3 ), oral fluid samples were liquid-liquid extracted (ButOAc/EtOAc, 1:1). As little as 1 microlitre of a mixture of this extract and the MALDI matrix (alpha-cyano-4-hydroxycinnamic acid) was spotted onto the MALDI plate and could directly be analyzed. With MALDI omitting chromatographic separation, very short analysis times of about 10 s per sample were possible. The method was developed and validated according to international guidelines including specificity, recovery, matrix effects, accuracy and precision, stabilities and limit of quantification. All validation criteria were fulfilled except for ion suppression/enhancement. Comparison with a routine liquid chromatography-tandem mass spectrometry (LC-MS/MS) method showed good agreement of the results. Applicability of the method was shown by analyzing about 250 oral fluid samples collected after controlled administration of 125 mg MDMA in a pharmacokinetic study. The whole lot of samples could be analyzed in less than 1 h, proving the ultra-high-speed of the method. PMID:25990956

  13. Determination of trace elements in various kinds of bean by X-ray spectrometric techniques (1995-96)

    Various kinds of bean such as Peanut, Gram Whole, Black Eye Bean, Small Red Bean, Lab Lab Bean, Green Mung Bean, Filed Pea, Seasame Seed, Sultani, Maize, Butter Bean, Dolichos Lab Lab, Toor Whole, Small Yellow Bean, Cow Pea have been collected and analysed by EDXRF analysis for trace elements. The measurement system consists of a Cd-109 annual excitation source, a Si (Li) detector, H V power supply, a spectrometry amplifier, a multichannel analyser and a personal computer. The samples were prepared as pressed pellets and measured by Emission Transmission Technique. The accuracy was determined by analysing standard reference material, SOIL-7 form IAEA. (author)

  14. Spectrometric mixture analysis: An unexpected wrinkle

    Robert De Levie

    2009-09-01

    The spectrometric analysis of a mixture of two chemically and spectroscopically similar compounds is illustrated for the simultaneous spectrometric determination of caffeine and theobromine, the primary stimulants in coffee and tea, based on their ultraviolet absorbances. Their analysis indicates that such measurements may need an unexpectedly high precision to yield accurate answers, because of an artifact of inverse cancellation, in which a small noise or drift signal is misinterpreted in terms of a concentration difference. The computed sum of the concentrations is not affected.

  15. 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.

  16. A novel, donor-active solvent-assisted liquid-phase microextraction procedure for spectrometric determination of zinc

    Kocurova, Livia; Fatlova, Martina; Bazel, Yaroslav; Serbin, Rastislav; Andruch, Vasil, E-mail: liviamonika.kocurova@gmail.com [Department of Analytical Chemistry, University of P. J. Safarik, Kosice (Slovakia); Balogh, Ioseph S. [Department of Chemistry, College of Nyiregyhaza (Hungary); Simon, Andras [Department of General and Analytical Chemistry, Budapest University of Technology and Economics, Budapest (Hungary); Badida, Miroslav; Rusnak, Radoslav [Department of Environmentalistics, Faculty of Mechanical Engineering, Technical University of Kosice (Slovakia)

    2014-02-15

    Based on the reaction of Zn(II), thiocyanate and 2-[2-(5-dimethylamino-thiophen-2-yl)-vinyl]- 1,3,3-trimethyl-3H-indolium bromide (DTVTI), a donor-active solvent-assisted liquid-phase microextraction procedure followed by spectrophotometric determination of zinc at 570 nm was developed. The optimum experimental conditions were investigated and found to be as follows: concentration of NH{sub 4}SCN 0.02 mol L{sup -1} concentration of DTVTI 4 x 10{sup -5} mol L{sup -1}. Various extraction solvents were studied alone as well as in mixtures with different improvers, and a mixture of toluene as the extraction solvent and tributylphosphate as the donor-active solvent in a 4:1 v/v ratio was selected. The calibration plot was linear up to 2.62 mg L{sup 1} of zinc with limit of detection 0.09 mg L{sup -1}. The developed procedure was applied for zinc determination in dietary supplements. (author)

  17. Energy dispersive x-ray fluorescence spectrometric determination of vanadium, nickel, and iron in petroleum and petroleum residua

    Trace metals such as vanadium, nickel, and iron in fluid catalytic cracking feedstocks deposit on the catalyst and adversely affect catalyst activity and product yields. Vanadium compounds can also cause damage to furnace linings and corrosion of boiler tubes or gas turbine blades. A rapid and sensitive analytical method is need to detect these metals in feedstocks, products, and residual. In this paper such a method using energy dispersive X-ray fluorescence (EDXRF) spectrometry for determination of vanadium, nickel, and iron in petroleum and petroleum residua is described. In order to eliminate matrix effects, samples containing an internal standard (cobalt) were decomposed by heating with concentrated sulfuric acid and the resulting carbonaceous residua were ashed. X-ray fluorescent spectral intensities of V, Ni, Fe, and Co were measured using established instrumental parameters. Since the Fe Kβ and Co Kα lines overlapped, the slope and the intercept of the ratio of Fe Kα to Fe Kβ intensities from the analysis of ash of several iron standards were used for correction of Co spectral intensities. Sample metal concentrations were determined by comparison of spectral ratios to those of ashed calibration standards

  18. A novel, donor-active solvent-assisted liquid-phase microextraction procedure for spectrometric determination of zinc

    Based on the reaction of Zn(II), thiocyanate and 2-[2-(5-dimethylamino-thiophen-2-yl)-vinyl]- 1,3,3-trimethyl-3H-indolium bromide (DTVTI), a donor-active solvent-assisted liquid-phase microextraction procedure followed by spectrophotometric determination of zinc at 570 nm was developed. The optimum experimental conditions were investigated and found to be as follows: concentration of NH4SCN 0.02 mol L-1 concentration of DTVTI 4 x 10-5 mol L-1. Various extraction solvents were studied alone as well as in mixtures with different improvers, and a mixture of toluene as the extraction solvent and tributylphosphate as the donor-active solvent in a 4:1 v/v ratio was selected. The calibration plot was linear up to 2.62 mg L1 of zinc with limit of detection 0.09 mg L-1. The developed procedure was applied for zinc determination in dietary supplements. (author)

  19. A laboratory manual for the determination of metals in water and wastewater by atomic absorption spectrophotometry

    This guide presents, in addition to a brief discussion of the basic principles and practical aspects of atomic absorption spectrophotometry, a scheme of analysis for the determination of 19 metals in water and wastewater, 16 by flame atomic absorption and 3 by vapour generation techniques. Simplicity, speed and accuracy were the main criteria considered in the selection of the various methods

  20. 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…

  1. Fractionation of trace elements in agricultural soils using ultrasound assisted sequential extraction prior to inductively coupled plasma mass spectrometric determination.

    Matong, Joseph M; Nyaba, Luthando; Nomngongo, Philiswa N

    2016-07-01

    The main objectives of this study were to determine the concentration of fourteen trace elements and to investigate their distribution as well as a contamination levels in selected agricultural soils. An ultrasonic assisted sequential extraction procedure derived from three-step BCR method was used for fractionation of trace elements. The total concentration of trace elements in soil samples was obtained by total digestion method in soil samples with aqua regia. The results of the extractable fractions revealed that most of the target trace elements can be transferred to the human being through the food chain, thus leading to serious human health. Enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), risk assessment code (RAC) and individual contamination factors (ICF) were used to assess the environmental impacts of trace metals in soil samples. The EF revealed that Cd was enriched by 3.1-7.2 (except in Soil 1). The Igeo results showed that the soils in the study area was moderately contaminated with Fe, and heavily to extremely polluted with Cd. The soil samples from the unplanted field was found to have highest contamination factor for Cd and lowest for Pb. Soil 3 showed a high risk for Tl and Cd with RAC values of greater than or equal to 50%. In addition, Fe, Ni, Cu, V, As, Mo (except Soil 2), Sb and Pb posed low environmental risk. The modified BCR sequential extraction method provided more information about mobility and environmental implication of studied trace elements in the study area. PMID:27058917

  2. Gamma spectrometric assessment of nuclear fuel

    Krištof, Edvard; Pregl, Gvido

    1990-12-01

    A description is given of a gamma spectrometric technique which has been developed with the aim of determining the amount of a certain radioactive fission product taking into consideration local variations of the linear attenuation coefficient of gamma rays. Also, an experiment using a fuel element of the TRIGA Mark II reactor in Ljubljana is presented.

  3. Determination of nine high-intensity sweeteners in various foods by high-performance liquid chromatography with mass spectrometric detection.

    Zygler, Agata; Wasik, Andrzej; Kot-Wasik, Agata; Namieśnik, Jacek

    2011-06-01

    An analytical procedure involving solid-phase extraction (SPE) and high-performance liquid chromatography-mass spectrometry has been developed for the determination of nine high-intensity sweeteners authorised in the EU; acesulfame-K (ACS-K), aspartame (ASP), alitame (ALI), cyclamate (CYC), dulcin (DUL), neohesperidin dihydrochalcone (NHDC), neotame (NEO), saccharin (SAC) and sucralose (SCL) in a variety of food samples (i.e. beverages, dairy and fish products). After extraction with a buffer composed of formic acid and N,N-diisopropylethylamine at pH 4.5 in ultrasonic bath, extracts were cleaned up using Strata-X 33 μm Polymeric SPE column. The analytes were separated in gradient elution mode on C(18) column and detected by mass spectrometer working with an electrospray source in negative ion mode. To confirm that analytical method is suitable for its intended use, several validation parameters, such as linearity, limits of detection and quantification, trueness and repeatibilty were evaluated. Calibration curves were linear within a studied range of concentrations (r(2) ≥ 0.999) for six investigated sweeteners (CYC, ASP, ALI, DUL, NHDC, NEO). Three compounds (ACS-K, SAC, SCL) gave non-linear response in the investigated concentration range. The method detection limits (corresponding to signal-to-noise (S/N) ratio of 3) were below 0.25 μg mL(-1) (μg g(-1)), whereas the method quantitation limits (corresponding to S/N ratio of 10) were below 2.5 μg mL(-1) (μg g(-1)). The recoveries at the tested concentrations (50%, 100% and 125% of maximum usable dose) for all sweeteners were in the range of 84.2 ÷ 106.7%, with relative standard deviations sweeteners in drinks, yoghurts and fish products. The procedure described here is simple, accurate and precise and is suitable for routine quality control analysis of foodstuffs. PMID:21465096

  4. Complete determination of the reflection coefficient in neutron specular reflection by absorptive nonmagnetic media

    An experimental method is proposed which allows a complete determination of the complex reflection coefficient for absorptive media for positive and negative values of the momenta. It makes use of magnetic reference layers, and is a modification of a recently proposed technique for phase determination based on polarization measurements. The complex reflection coefficient resulting from a simulated application of the method is used for a reconstruction of the scattering density profiles of absorptive nonmagnetic media by inversion

  5. Determination of optical absorption edge in amorphous thin films of selenium and selenium dopped with sulphur

    The transmittance and the reflectance of three thin films of S-Se alloys have been determined for different wavelengths in the range 5000-11000 A. Accurate methods had been used to calculate the optical constants n and k as well as the absorption coefficient K. The determined absorption edges for S-Se alloys shifts to higher photon energies by increasing the concentration of sulphur content. (author)

  6. Determinants of drug absorption in different ECMO circuits

    E.D. Wildschut (Enno); M.J. Ahsman (Maurice); K. Allegaert (Karel); R.A.A. Mathot (Ron); D. Tibboel (Dick)

    2010-01-01

    textabstractPurpose: The aim of this in vitro study was to evaluate potential determinants of drug loss in different ECMO circuits. Methods: Midazolam, morphine, fentanyl, paracetamol, cefazolin, meropenem and vancomycin were injected into three neonatal roller pump, two paediatric roller pump and t

  7. Characterization of the oral absorption of several aminopenicillins: determination of intrinsic membrane absorption parameters in the rat intestine in situ

    Sinko, P. J.; Amidon, G. L.

    1992-01-01

    The absorption mechanism of several penicillins was characterized using in situ single-pass intestinal perfusion in the rat. The intrinsic membrane parameters were determined using a modified boundary layer model (fitted value +/- S.E.): Jmax* = 11.78 +/- 1.88 mM, Km = 15.80 +/- 2.92 mM, Pm* = 0, Pc* = 0.75 +/- 0.04 for ampicillin; Jmax* = 0.044 +/- 0.018 mM, Km = 0.058 +/- 0.026 mM, Pm* = 0.558 +/- 0.051, Pc* = 0.757 +/- 0.088 for amoxicillin; and Jmax* = 16.30 +/- 3.40 mM, Km = 14.00 +/- 3.30 mM, Pm* = 0, Pc* = 1.14 +/- 0.05 for cyclacillin. All of the aminopenicillins studied demonstrated saturable absorption kinetics as indicated by their concentration-dependent wall permeabilities. Inhibition studies were performed to confirm the existence of a nonpassive absorption mechanism. The intrinsic wall permeability (Pw*) of 0.01 mM ampicillin was significantly lowered by 1 mM amoxicillin and the Pw* of 0.01 mM amoxicillin was reduced by 2 mM cephradine consistent with competitive inhibition.

  8. Determinants of drug absorption in different ECMO circuits

    Wildschut, Enno; Ahsman, Maurice; Allegaert, Karel; Mathot, Ron; Tibboel, Dick

    2010-01-01

    textabstractPurpose: The aim of this in vitro study was to evaluate potential determinants of drug loss in different ECMO circuits. Methods: Midazolam, morphine, fentanyl, paracetamol, cefazolin, meropenem and vancomycin were injected into three neonatal roller pump, two paediatric roller pump and two clinically used neonatal roller pump circuits, all with a silicone membrane, and two neonatal centrifugal pump circuits with polypropylene hollow-fibre membranes. Serial blood samples were taken...

  9. Determination of iron absorption and excretion by whole-body counting

    Using a whole-body counter, the authors have studied 59Fe absorption and loss in 8 normal subjects and in 30 iron deficient patients. Results showed that whole-body counting provided an excellent and simple method for iron retention measurements, obviating many inaccuracies of previous technic. Normal absorption of radio iron with this procedure has ranged from 9 per cent to 20 per cent of the administered tracer in normal subjects, with a mean of 15 per cent. A significant increase in 59Fe absorption was noted in 21 iron-deficient patients in whom the retention ranged from 40 to 100 per cent. However, 3 iron-deficient patients were found to have low absorption, and their severe iron deficiency could be correlated with this defect in absorption. This method permits also the determination of the rate of iron excretion during the following months and therefore the study of the mechanism of some pathological loss. (authors)

  10. 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

  11. Application of Fiber Bragg Grating for Determining Positions of Gas Absorption Lines

    韩文念; 汪曣; 马凤; 刘琨; 贾大功; 刘铁根; 张红霞

    2010-01-01

    Fiber Bragg grating(FBG) is used as a wavelength reference device to calibrate the position of gas absorption peak in the intracavity absorption gas sensor(ICAGS) based on erbium-doped fiberring laser.This system can detect both the reflectance spectrum of FBGs and absorption spectrum of measured gas during a single wavelength sweeping process by linearly varying the driving voltage of optic filter.The voltages corresponding to center wavelength positions of four FBGs in the spectrum are determined through ...

  12. Calcium Absorption in Infants and Small Children: Methods of Determination and Recent Findings

    Steven A. Abrams

    2010-04-01

    Full Text Available Determining calcium bioavailability is important in establishing dietary calcium requirements. In infants and small children, previously conducted mass balance studies have largely been replaced by stable isotope-based studies. The ability to assess calcium absorption using a relatively short 24-hour urine collection without the need for multiple blood samples or fecal collections is a major advantage to this technique. The results of these studies have demonstrated relatively small differences in calcium absorption efficiency between human milk and currently available cow milk-based infant formulas. In older children with a calcium intake typical of Western diets, calcium absorption is adequate to meet bone mineral accretion requirements.

  13. Determination of absorption cross-section of Si nanocrystals by two independent methods based on either absorption or luminescence

    Absorption cross-section (ACS) of silicon nanocrystals (SiNCs) is determined via two completely independent approaches: (i) Excitation-intensity-dependent photoluminescence (PL) kinetics under modulated (long square pulses) pumping and (ii) absorbance measured by the photothermal deflection spectroscopy combined with morphology information obtained by the high-resolution transmission electron microscopy. This unique comparison reveals consistent ACS values around 10−15 cm2 for violet excitation of SiNCs of about 3–5 nm in diameter and this value is comparable to most of direct band-gap semiconductor nanocrystals; however, it decreases steeply towards longer wavelengths. Moreover, we analyze the PL-modulation technique in detail and propose an improved experimental procedure which enables simpler implementation of this method to determine ACS of various (nano)materials in both solid and liquid states

  14. Determination of absorption cross-section of Si nanocrystals by two independent methods based on either absorption or luminescence

    Valenta, J., E-mail: jan.valenta@mff.cuni.cz; Greben, M. [Department of Chemical Physics and Optics, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Prague 2 (Czech Republic); Remeš, Z. [Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, Prague 6 (Czech Republic); Gutsch, S.; Hiller, D.; Zacharias, M. [Faculty of Engineering, IMTEK, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany)

    2016-01-11

    Absorption cross-section (ACS) of silicon nanocrystals (SiNCs) is determined via two completely independent approaches: (i) Excitation-intensity-dependent photoluminescence (PL) kinetics under modulated (long square pulses) pumping and (ii) absorbance measured by the photothermal deflection spectroscopy combined with morphology information obtained by the high-resolution transmission electron microscopy. This unique comparison reveals consistent ACS values around 10{sup −15} cm{sup 2} for violet excitation of SiNCs of about 3–5 nm in diameter and this value is comparable to most of direct band-gap semiconductor nanocrystals; however, it decreases steeply towards longer wavelengths. Moreover, we analyze the PL-modulation technique in detail and propose an improved experimental procedure which enables simpler implementation of this method to determine ACS of various (nano)materials in both solid and liquid states.

  15. Experimental determination of resonance absorption cross sections for Zircaloy-2 and zirconium

    The integral absorption cross section for the neutron spectrum and the thermal absorption cross section for zircaloy-2 have been determined using the pile oscillator technique. Using both values and a measured ratio of the epithermal to the thermal flux, the effective resonance integrals were obtained. After subtraction of the contributions for alloy and impurity elements, the effective resonance integrals for zirconium were evaluated. An extrapolated value of 0.91±0.10 was obtained for the dilute integral. (author)

  16. Determination of traces of cadmium in zinc by flameless atomic absorption spectrophotometry after extraction

    Janssen, A.; Willmann, K.H.; Simon, F.J.

    1985-01-01

    The suitability of dithizone, diethyldithiocarbamate and tetramethylendithiocarbamate as chelating agents for the extraction-photometric cadmium determination by flameless atomic absorption spectrophotometry in the presence of zinc was investigated. It has been found that the extraction of the dithizone chelate by carbon tetrachloride permits an uninfluenced determination of cadmium in the presence of a zinc excess up to 10/sup 5/. Therefore the use of flameless atomic absorption spectrophotometry raises the selectivity as compared to photometry, because photometry only permits a 1000-fold excess of zinc. With this method 2x10/sup -4/% of cadmium in zinc can be determined without further corrections of matrix effects.

  17. 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.

  18. Capturing Absorptive Capacity: Concepts, Determinants, Measurement Modes and Role in Open Innovation

    Lewandowska Małgorzata Stefania

    2015-03-01

    Full Text Available Absorptive capacity (ACAP enables firm to adjust to a rapidly changing environment and achieve sustained competitive advantage. This study contributes to the existing body of knowledge on ACAP by providing a comprehensive literature review of the various conceptual attributes of the construct, its determinants, outcomes, and positive and negative consequences of using its input-oriented, output-oriented, and perceptive measurement modes. Proposals for constructing ACAP based on the Community Innovation Survey (CIS empirically illustrate for the conceptual part of the paper. Additionally, combining concepts of absorptive capacity and open innovation (which is still rare in the literature provides a new perspective on the role of absorptive capacity in opening up the innovation process. This advances the understanding of both inter-related proposals. The article also identifies key problems and formulates future research directions to improve the multi-level characteristics of absorptive capacity.

  19. Spectrometric techniques 2

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume II provides information pertinent to vacuum ultraviolet techniques to complete the demonstration of the diversity of methods available to the spectroscopist interested in the ultraviolet visible and infrared spectral regions. This book discusses the specific aspects of the technique of Fourier transform spectroscopy.Organized into five chapters, this volume begins with an overview of the large number of systematic effects in the recording of an interferogram. This text then examines the design approach for a Fourier transform spectrometer with focus on optics.

  20. 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...

  1. Application of Fiber Bragg Grating for Determining Positions of Gas Absorption Lines

    HAN Wennian; WANG Yan; MA Feng; LIU Kun; JIA Dagong; LIU Tiegen; ZHANG Hongxia

    2010-01-01

    Fiber Bragg grating(FBG)is used as a wavelength reference device to calibrate the position of gas absorption peak in the intracavity absorption gas sensor(ICAGS)based on erbium-doped fiberring laser.This system can detect both the reflectance spectrum of FBGs and absorption spectrum of measured gas during a single wavelength sweeping process by linearly varying the driving voltage of optic filter.The voltages corresponding to center wavelength positions of four FBGs in the spectrum are determined through Gaussian peak fitting.Then,the wavelengths of gas absorption lines are deduced from the correspondence between driving voltage and wavelength obtained by quadratic curve fitting.The maximum error of wavelength of acetylene absorption lines between experimental results and those from HITRAN database is 0.106 nm and the resolving accuracy of two adjacent absorption lines is about93.593%.By using this method,ICAGS can theoretically recognize the measured gas type and monitor multi-gas components.

  2. 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.

  3. Determination of vitamin B12 (cobalamine) absorption by means of a simple double-isotope technique

    The background, practical instruction and clinical results of a simplified method of determining the absorption of cobalamine (vitamin B12) are presented. The simultaneous administration of 57CO-CN-cobalamine, a non-absorbable marker (51CrCl3), and red carmine tablets enable quantitative assessments of the cobalamine absorption by collection of a small red feaces sample. In contrast to the classical Schilling-test, this vitamin B12 absorption test (B12-ABS-test) or faeces-spot-test is, independent of fasting, flushing dose, renal function and diurnal urinary collection. This is documented in a series of clinical studies. The B12-ABS-test provides accurate and precise results compared to the reference method (whole-body-counting). The Schilling test, on the contrary, gives approximately 50% false low values in a reference group of elderly hospitalized patients. A modification of the B12-ABS-test, has been used to determine the cobalamine absorption in children, and a set of age-related reference intervals have been established, together with quantitative measurements of the cobalamine absorption in children with small bowel diseases. Based on several years of practical experience, we recommend replacement of the Schilling test by this simple double-isotope technique. (author)

  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. 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

  6. Selenium determination in biological material by atomic absorption spectrophotometry in graphite furnace and using vapor generation

    The applicability of the atomic absorption spectrophotometry to the determination of selenium in biological material using vapor generation and electrothermal atomization in the graphite furnace was investigated. Instrumental parameters and the analytical conditions of the methods were studied. Decomposition methods for the samples were tested, and the combustion in the Wickbold apparatus was chosen. (author)

  7. Determination of atmospheric corrosion of coated steel surfaces by in situ infrared reflection absorption spectroscopy (IRRAS)

    Full text: Infrared reflection absorption spectroscopy (IRRAS) is a sensitive technique for measuring thin layers on metallic surfaces. The principal goal of this IRRAS study was the development of a reproducible and reliable in situ measurement procedure for the determination of corrosion of coated steel surfaces. (author)

  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. Chemical modifiers in electrothermal atomic absorption determination of Platinum and Palladium containing preparations in blood serum

    Аntonina Alemasova

    2012-11-01

    Full Text Available The biological liquids matrixes influence on the characteristic masses and repeatability of Pt and Pd electrothermal atomic absorption spectroscopy (ETAAS determination was studied. The chemical modifiers dimethylglyoxime and ascorbic acid for matrix interferences elimination and ETAAS results repeatability improvement were proposed while bioliquids ETAAS analysis, and their action mechanism was discussed.

  10. 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)