The paraffin wax was used as a diluent for 1-nitroso-2-naphthol(HA) and trioctylphosphine oxide(TOPO) in the extraction of lanthanides at 70℃. The composition of the extracted species was given as LnA3(TOPO)2 by means of the slope analysis. The variation of the synergistic extraction equilibrium constant(Ksex) was investigated at 60～80℃, and the thermodynamic data were calculated. The dependence of separation factors on temperature was also studied.
董学畅; 贾智若; 刘志华; 缪明明; 翁哲慧
Full Text Available A number of mixed ligand complexes of alkali metal salts of o-nitrophenol,2,4-dinitrophenol, 2,4,6,- trinitrophenol, 1-nitroso-2- naphthol and 8- hydroxyquinoline with Insoniroso–p methylacetopheone have been synthesized in absolute ethanol & characterized by elemental analysis and I .B. spectral data. Their I.R spectral data indicate the presence of hydrogen bonding in them, which many be one of the dominant factors of their stability. Further appreciable shift in 1650 cm-1 band (possibly vC=O and 1600 cm-1 band (possibly vC=NSuggests their coordination behavior in these mixed ligand complexes The reactions that take place in natural systems are highly specific and selective. Alkali metal ions actively participate in most of the reaction occurring in the biological systems, which are dominated by mixed ligand complexes. Studies of such mixed ligand complexes of alkali metals can threw light in understanding the role and mechanism of selective absorption of alkali metals ions by plants Coordinating ability of alkali metal with isonitrosoacetophenone1-2 and transition metals with isonitrosoacetophenone3 and isonitroso-p-methylacetophenone4 have been reported earlier. In the present paper we report the mixed ligand complexes of alkali metal salts having the general formula ML.HL, ‘ where M=Li, Na & K and L=deprotonated o- nitrophenol, 2,4 dinitrophenol, 2, 4, 6- trinitrophenol, 1-nitroso-2-naphthol or 8- hydroxquinoline; HL’= p -MeHINAP (isonitroso-p-methylacetophenone.
Thyssen, Jacob P.; Menné, Torkil; Johansen, Jeanne D.;
Background: It is often difficult to establish clinical relevance of metal exposure in cobalt-allergic patients. Dermatologists and patients may incorrectly assume that many metallic items release cobalt at levels that may cause cobalt dermatitis. Cobalt-allergic patients may be unaware...... that they are exposed to cobalt from handling work items, causing hand dermatitis. Objectives: To present early findings with a newly developed cobalt spot test. Methods and Results: A cobalt spot test based on disodium-1-nitroso-2-naphthol-3,6-disulfonate was able to identify cobalt release at 8.3 ppm. The test may...... also be used as a gel test if combined with an agar preparation. We found no false-positive reactions when testing metals and alloys known not to contain cobalt. However, one cobalt-containing alloy, which elicited cobalt dermatitis in cobalt-allergic patients, was negative upon cobalt gel testing...
Full Text Available Rapid photometric assessment of iron in blood plasma and serum by a simple procedure after the extraction of iron(II complex with 1-nitroso-2-naphthol in the micellar phase of a nonionic surfactant at the cloud point upon heating (pH range is 4.5–6.3 is proposed. The procedure trueness was verified using a standard reference protocol using bathophenanthroline. The advantages of the procedure are higher sensitivity than the reference protocol: the limit of detection is 0.03 μg/mL, the limit of quantitation is 0.1 μg/mL, the determination range is 0.1 – 2.8 μg/mL (RSD 0.02–0.10. Copper does not interfere with the iron assessment.
Samarina, Tatyana; Proskurnin, Mikhail
Rapid photometric assessment of iron in blood plasma and serum by a simple procedure after the extraction of iron(II) complex with 1-nitroso-2-naphthol in the micellar phase of a nonionic surfactant at the cloud point upon heating (pH range is 4.5-6.3) is proposed. The procedure trueness was verified using a standard reference protocol using bathophenanthroline. The advantages of the procedure are higher sensitivity than the reference protocol: the limit of detection is 0.03 μg/mL, the limit of quantitation is 0.1 μg/mL, the determination range is 0.1 - 2.8 μg/mL (RSD 0.02-0.10). Copper does not interfere with the iron assessment.
The method of paper chromatography for the separation and quantitative determination of iron, copper, cobalt and nickel in pyrite and chalcopyrite is described.The three systems of ehromtograpbie solvents for the separation of iron, copper, cobalt and nickel on the 8×25 or 15×26 cm Whatman No. 3, involving acetone-hydrochloric acid-water, butanone-hydrochloric acid-water and acetone-acetylacetone-hydrochloric acid-water have been tested. As a developing system for the separation of this four elements in samples, the mixture of aoetone-acetylacetone-hydroehlorio acid-water is considered to be the best. After developing in a 30×40 cm glass dryer, the paper is dried in air and rendered the zone visible by treatment with 0.1% (W/V) rubeanic acid solution. The R1 values, colour reactions with this spray reagent and the eolour are given. A good paper chromatography of elements has been obtained. The elements are determined by colorimetrie method, with 1-nitroso-2-naphthol for cobalt,1-(2-pyridylozo)-2-naphthol for nickel, oxalic acid bis-cyelohexylidene hydrozide for copper, and sulfosalicylic acid for iron. In addition, iron and copper can also be determined by titration with potassium dichromate solution and iodimetry respectively.
SNEZANA S. MITIC
Full Text Available The aim of this work was to develop a new kinetic spectrophoto-metric method for the determination of ibuprofen in pharmaceutical for-mulations. Ibuprofen was determined in an acidic ethanolic medium by monitoring the rate of appearance of 1-nitroso-2-naphthol, resulting from the displacement by ibuprofen of Co(III from the tris(1-nitroso-2-naptholatocobalt(III complex. The optimum operating conditions regarding reagent concentrations and temperature were established. The tangent method was adopted for constructing the calibration curve, which was found to be linear over the concentration range 0.21–1.44 and 1.44–2.06 µg ml-1. The optimized conditions yielded a theoretical detection limit of 0.03 µg ml-1 based on the 3.3 S0 criterion. The interference effects of the usual excipients of powdery drugs, foreign ions and amino acids on the reaction rate were studied in order to assess the selectivity of the method. The developed procedure was successfully applied for the rapid determination of ibuprofen in commercial pharmaceutical formulations and human control serum. The unique features of this procedure are that the determination can be performed at room temperature and the analysis time is short. The newly developed method is simple, inexpensive and efficient for use in the analysis of a large number of samples.
Sharma, A.; Tapadia, K.; Sahin, R.; Shrivas, K.
A surfactant-assisted nanodrop spectrophotometric (NDS) method has been developed for the determination of the iron(III) content in single drops (1 μ L) of food, biological, and or environmental sample using disodium 1-nitroso-2-naphthol-3,6-sulfonate (Nitroso-R salt) as a complexing agent and Tween-80 as non-ionic surfactant at pH 4.0. This method is based on the formation of a complex between the Fe(III) present in a sample and the Nitroso-R-salt in the presence of a surfactant to form a green-colored Fe(III)-Nitroso-R salt complex, which can be measured using a NDS method at a λ max = 710 nm. This system was found to obey Beer's law at concentrations in the range of 50-5000 μ g/L with slope, intercept and correlation coefficient values of 0.683, 0.102, and 0.986, respectively. The molar absorptivity of the complex in terms of the Fe(III) content was determined to be 4.86 × 10 5 L· mol -1 · cm -1 . The detection limit and %RSD values of the method were found to be 17 × 10-3 mg/L and ±1.3706%, respectively. This newly developed method was successfully applied to the determination of the Fe(III) content in single drops of food, biological, and environmental samples, and the results were compared with those obtained by atomic absorption spectrometry.
Polásek, Miroslav; Petriska, Ivan; Pospísilová, Marie; Jahodár, Ludek
Molybdate was examined as a complex-forming additive to the CE background electrolytes (BGE) to affect the selectivity of separation of polyhydric phenols such as flavonoids (apigenin, hyperoside, luteolin, quercetin and rutin) and hydroxyphenylcarboxylic acids (ferulic, caffeic, p-coumaric and chlorogenic acid). Effects of the buffer concentrations and pH and the influence of molybdate concentration on the migration times of the analytes were investigated. In contrast to borate (which is a buffering and complex-forming agent generally used in CE at pH > or =9) molybdate forms more stable complexes with aromatic o-dihydroxy compounds and hence the complex-formation effect is observed at considerably lower pH. Model mixtures of cinnamic acid, ferulic acid, caffeic acid and 3-hydroxycinnamic acid were separated with 25 mM morpholinoethanesulfonic acid of pH 5.4 (adjusted with Tris) containing 0.15 mM sodium molybdate as the BGE (25 kV, silica capillary effective length 45 cm x 0.1mm I.D., UV-vis detection at 280 nm). With 25 mM 2-hydroxy-3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulphonic acid/Tris of pH* 7.4 containing 2mM sodium molybdate in aqueous 25% (v/v) methanol as the BGE mixtures of all the above mentioned flavonoids, p-coumaric acid and chlorogenic acid could be separated (the same capillary as above, UV-vis detection at 263 nm). The calibration curves (analyte peak area versus concentration) were rectilinear (r>0.998) for approximately 8-35 microg/ml of an analyte (with 1-nitroso-2-naphthol as internal standard). The limit of quantification values ranged between 1.1 mg l(-1) for p-coumaric acid and 2.8 mg l(-1) for quercetin. The CE method was employed for the assay of flavonoids in medicinal plant extracts. The R.S.D. values ranged between 0.9 and 4.7% (n=3) when determining luteolin (0.08%) and apigenin (0.92%) in dry Matricaria recutita flowers and rutin (1.03%) and hyperoside (0.82%) in dry Hypericum perforatum haulm. The recoveries were >96%. PMID