The fluorimetric determination of formaldehyde

A sensitive fluorimetric procedure for formaldehyde has been developed. The method, which can measure 0.01 μg formaldehyde, is based on the Hantzsch reaction between acetylacetone, ammonia, and formaldehyde. The product, 3,5-diacetyl-I,4-dihydrolutidine, is colored yellow and fluoresces yellow green. Infra-red spectra indicate that this compound is ionic in dilute solution and aggregated in concentrated solution. The Hantzsch reaction may be extended for the assay of other aldehydes, amines, and β-diketones.     

The fluorimetric determination of phosphate with thiamine

A method for the microdetermination of sulphur in organic compounds by means of combustion in a flow of oxygen is described. The oxides of sulphur are absorbed and stored on a small silver layer. After completion of the combustion, the oxygen is replaced first by nitrogen and secondly by hydrogen which liberates the sulphur as sulphur dioxide and regenerates the silver layer. The sulphur dioxide can be easily absorbed by dilute hydrogen peroxide and determined by any convenient method.     

Simplified fluorimetric determination of digitalis alkaloids;.

A new fluorimetric procedure for the determination of digoxin and digitoxin is described. The method is based upon the development of a fluorophore when the digitalis drugs are treated with concentrated sulfuric acid. Applications to tablet and elixir forms of the drugs are described.     

催化荧光光度法测定血红蛋白

基于血红蛋白(Hb)对过氧化氢氧化靛蓝胭脂红体系的催化作用,建立了模拟酶催化荧光光度法测定血红蛋白的新方法并对催化氧化反应的机理进行了初步探讨。实验发现体系的荧光强度与血红蛋白浓度在6.20×10-11~7.75×10-8mol/L范围内线性关系良好,方法的检出限为1.67×10-11mol/L。方法用于人血中血红蛋白含量的测定,回收率为98.8%~103.2%。     

Chromato-photocolorimetric determination of digoxin

Procedures have been developed for the quantitative determination of digoxin as such and in solutions for injection and tablets by a chromato-photocolorimetric method with the aid of which it is possible to obtain reliable results with adequate accuracy. The relative error of the determination does not exceed ±4.0%.All-Union Scientific-Research Institute of Pharmacy, Moscow. Tashkent Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 66–71, January–February, 1985.     

Flow injection fluorimetric determination of thiourea

A flow injection configuration for the fluorimetric determination of thiourea is proposed. The procedure is based on the rapid oxidation of thiourea by thallium(III) with concomitant formation of fluorescent thallium(I). Linear calibration graphs were obtained between 5 x 10(-7) and 1 x 10(-5)M, with a sampling rate of 90 samples/hr. The usefulness of the method was tested in the determination of thiourea in fruit juices and fruit peels.     

Long-wavelength stopped-flow fluorimetric determination of lysozyme

The use of Cresyl Violet and sodium dodecyl sulphate for the kinetic fluorimetric determination of lysozyme from dynamic fluorescence measurements at a long wavelength in the range near 600 nm was explored. The high initial rate of this system allows analytical measurements to be made within ca. 2 s after the reactants are mixed, by using the stopped-flow mixing technique, which makes the method applicable to automatic routine analysis. The calibration graph is linear over the range 0.5-40 mug ml(-1) lysozyme hydrochloride and the detection limit of 0.19 mug ml(-1). The precision is less than 2% (relative standard deviation). The results obtained by applying the proposed method to the analysis of pharmaceutical samples with no pretreatment shown how readily it can be adapted for routine analyses. Analytical recoveries ranged between 94.0 and 104.0%.     

基于痕量联苯胺阻尼作用的荧光光度分析

在HCl介质中，联苯胺的存在对KBrO3氧化吡咯红反应有抑制作用，据此建立了测定痕量联苯胺的荧光动力学新方法。对方法的介质条件、试剂用量、干扰物质影响进行了系统研究。在最佳实验条件下，方法的线性范围为30～400ng／mL，检出限为14．4ng／mL，对11份浓度为80ng／mL，300ng／mL的联苯胺标准溶液进行平行测定，相对标准偏差分别为2．1％和1．2％。本法用于塑料和雨水中联苯胺的测定，回收率为97．8％～102．1％。     

协同催化荧光法测定痕量钴的研究

基于在硼酸 硼砂介质中,钴和三乙醇胺协同催化过氧化氢氧化还原型罗丹明6G的反应,建立了协同催化荧光法测定痕量钴的新方法。钴的检出限为0.011ng/mL;测定范围0.016～0.80ng/mL。方法已用于小麦粉,玉米粉,VB12和人尿液等样品中痕量钴的测定。     

Flow-injection fluorimetric determination of nabam and metham

A simple and sensitive flow-injection fluorimetric method was developed to determine nabam or metham in water and cereal samples. The procedure is based on the oxidation of these pesticides by thallium(III) with the concomitant formation of fluorescent thallium(I). Lineal calibration graphs were obtained between 0.25 and 2.56 muml(-1) for nabam, and between 0.26 and 2.65 mug ml(-1) for metham. The sampling rate was 80 samples h(-1). The method was satisfactorily applied to the direct analysis of water, wheat, barley and oat samples spiked with nabam or metham.     

阻抑荧光动力学法测定痕量司帕沙星

研究了Tris水溶液中司帕沙星对Cu（Ⅱ）催化H2O2氧化罗丹明B荧光猝灭体系的抑制作用,发现司帕沙星的质量浓度在0.098～1.372 ng/mL范围内与该体系的荧光强度成良好的线性关系,据此,建立了动力学荧光测定痕量司帕沙星的新方法.该方法检出限可达0.058 ng/mL,并用于制剂及体液中司帕沙星的分析,回收率为98.3%～102.1%.     

Spectrophotometric and fluorimetric determination of nomifensine maleate

Three methods have been developed for the determination of nomifensine maleate alone and in capsules: a spectrophotometric, an iodine charge-transfer, and a spectrofluorimetric method. All three give linear calibration graphs, over the ranges 20-100, 1-5 and 0.1-0.5 microg/ml, respectively, with coefficients of variation of 0.8, 1.3 and 1.3%, respectively.     

Stopped-flow fluorimetric determination of ampicillin in serum

A very simple and fast kinetic fluorimetric method for the determination of ampicillin is described. It is based on the stopped-flow technique and the addition of hydrogen peroxide to the reaction medium, and requires no prior heating to hydrolyse the -lactam ring unlike most hitherto known determinations. Kinetic data can be obtained only a few seconds after the reactants have been mixed, which allows ready application of the method to routine analyses. The calibration graph is linear over the range 0.025–7.0 g ml^–1 ampicillin. The detection limit is 20 ng/ml and within-and between-assay precision is 2.6% resp. 2.7%. The method was satisfactorily applied to the analysis of serum samples by including a preliminary deproteination step using trichloroacetic acid. Mean recovery is 102.1%.     

动力学荧光法分析痕量碘的研究

基于在磷酸介质中，碘能催化过碘酸钾氧化罗丹明6G的反应，使荧光猝灭，建立了催化荧光法测定痕量碘的新方法。方法的检出限为0．019mg/L，线性范围为0．020mg/L-0.80mg/L，可直接用于加碘食盐、海带、紫菜和盐酸胺碘酮药片中碘的测定。