动力学光度法测定痕量甲醛

在稀硫酸溶液中,甲醛对KClO3氧化罗丹明6G褪色反应有催化作用,研究了其动力学条件,建立了测定痕量甲醛的动力学光度分析方法,线性范围为0.02～1.8μg/mL,检出限为1.5×10-8g/mL。该法用于湖水、饮料和漆料中痕量甲醛的测定,标准加入回收率为93.8%～108.5%,RSD为2.6%～3.4%。     

乙基橙-溴酸钾体系动力学光度法测定痕量甲醛

研究了在稀H2SO4介质中,痕量甲醛催化KBrO3氧化乙基橙褪色反应的适宜条件和影响因素,建立了测定痕量甲醛的动力学光度法。方法采用固定时间法于507 nm波长处测量体系的吸光度,在适宜条件下,ΔA与甲醛质量浓度具有良好的线性关系,方法的线性范围为0~0.24 mg/L,检出限为0.004 mg/L。该方法用于饮料、废水和废气中痕量甲醛的测定,测定结果的相对标准偏差RSD≤3%(n=6),回收率为102%。     

催化荧光动力学法测定食品中痕量甲醛

基于在酸性条件中,甲醛催化KBrO3氧化吡口罗红B的褪色反应,使其荧光猝灭,建立了荧光动力学法测定痕量甲醛的新方法。反应在沸水浴中进行8 min,测定甲醛的线性范围为0.016~0.14 mg/L,检出限为8.6×10-6g/L。该方法用于水发食品中甲醛的测定,并进行了加标回收试验,回收率在96.0%~104.2%之间,相对标准偏差为1.7%~3.5%。     

吖啶红动力学荧光法测定痕量甲醛

在H2SO4介质中，以KCIO3-吖啶红为指示反应，建立了测定甲醛的动力学荧光分析法。方法的线性范围为40～600μg／L，检出限为27μg／L。方法用于树脂整理特殊织物和动物标本室内空气中甲醛的测定，与标准方法乙酰丙酮分光光度法进行对照，所测结果经t-检验无显著性差异。     

Kinetic spectrophotometric method for gold(III) determination

The kinetic spectrophotometric method for Au(III) determination was developed and validated. It was based on the catalytic effect of gold on the oxidation of methylene blue B (3,7di-(dimethyl amino)-10-dehydro-phenotiazin chloride) by ammonium peroxo-disulfate in citric buffer solution. There was the linearity of the calibration curve in the concentration range from 0.09 to 2.90 μg ml⁻¹ Au(III). The relative standard deviation was 2.50% and correlation coefficient of 0.9999. The limit of detection was determined as signal to noise ratio (3:1) and it was 5.5 ng ml⁻¹. The limit of quantification, based on signal to noise ratio 10:1 was 19.25 ng ml⁻¹. The selectivity was tested on the basis of influence of known amounts of different ions in the reaction mixture, upon the reaction rate. Kinetic and thermodynamic parameters were reported for both catalytic and non-catalytic reactions. The method was verified by Au(III) determination in anti-rheumatic drug “Tauredon” and in human urine samples, using ICP-AES as the comparative method. As the method is accurate, reliable, quick and simple it could be useful for clinical and toxicological practice.     

靛蓝胭脂红-溴酸钾体系催化光度法测定微量碘

研究了在室温及0．4mol/L H2SO4介质中碘离子对KBrO3氧化靛蓝胭脂红褪色反应的催化作用,建立了一种测定微量碘的新方法。碘离子浓度在0．20－2．0μg/mL范围内与△A呈线性关系,检测限为0．14μg/mL。多数常见离子无干扰。可用于海带中微量碘的测定。     

环境样品中痕量甲醛的催化荧光动力学分析

基于在硫酸介质中, 痕量甲醛能促进溴酸钾氧化吡咯红并使其荧光强度减弱的反应, 建立了动力学荧光法分析测定痕量甲醛的新方法. 研究了温度、时间, 各种试剂浓度等条件对测定的影响. 在最佳实验条件下, 方法的线性范围是8～200 ng/mL, 检出限为6.1 ng/mL. 该方法用于环境水样、室内空气、食品中痕量甲醛的测定, 并与乙酰丙酮分光光度法进行了对照, 结果无显著性差异.     

顺序注射催化动力学光度法测定织物和室内空气中痕量甲醛

在磷酸介质中 ,甲醛可以催化溴酸钾氧化　花青的反应使其退色 ,据此建立了顺序注射催化动力学光度法测定织物和室内空气中痕量甲醛的新方法。方法的线性范围 0 .5～ 7.0 μg mL ,检出限 0 .1 μg mL。用于树脂整理特殊织物和室内空气中痕量甲醛的测定 ,回收率在 97.0 %～ 1 0 5 .0 %之间。     

动力学分光光度法及荧光光度法测定痕量甲醛

在稀硫酸溶液中,研究了甲醛对催化KClO3氧化丁基罗丹明B褪色及荧光猝灭的动力学条件,建立了测定痕量甲醛的动力学光度及荧光光度分析方法,方法线性范围分别为0.02～0.27μg/mL和0.01～2.45μg/mL,检出限分别为1.2×10-8g/mL和3.8×10-9g/mL。该法灵敏度较高,选择性较好,用于湖水、饮料和漆料中痕量甲醛的测定,结果令人满意。     

Kinetic and maximum-absorbance spectrophotometric methods for the determination of olanzapine

Two simple and sensitive spectrophotometric methods were developed for the determination of olanzapine (OLZ) based on its oxidation with potassium iodate in a sulfuric acid medium to produce an intense violet-colored species exhibiting a maximum absorbance at 537 nm. The initial rate of formation and the maximum absorbance of the violet-colored oxidized product were monitored, in the first and second methods. The various experimental parameters affecting the rate of development and stability of the oxidized product were carefully studied and optimized. Beer’s law was obeyed up to 4.0 and 7.0 μg cm⁻³ OLZ with correlation coefficients of 0.998 and 0.996 (n = 6) and detection limits of 0.1 and 0.15 μg cm⁻³, for the initial rate and maximum absorbance methods. The proposed methods were conveniently applied to the determination of OLZ in its dosage forms and in spiked serum samples. Correspondence: Ashraf A. Mohamed, Department of Chemistry, Faculty of Science, King Faisal University, P.O. Box 1759, Al-Hassa-31982, Saudi Arabia.     

催化动力学电位法测定甲醛

基于硫酸介质中，甲醛对溴酸钾氧化碘化钾的促进作用，用碘离子选择电极跟踪Ⅰ^-，建立了测定微量甲醛的动力学电位法。方法的线性范围为0～5mg/L，检出限为0．055mg／L。利用此法测定了废水和空气中的甲醛含量，结果满意。     

酶催化动力学光度法测定锌

近年来酶法在分析测定方面的研究非常活跃,酶法测定锌已有报道,基本为终点测定法。本文中的研究是基于LDH催化下列反应：丙酮酸＋NADH=乳酸＋NAD^＋（氧化型烟酰胺腺嘌呤二核苷酸）,锌离子的存在对酶催化反应具有抑制作用,反应速度的变化率与锌离子的浓度呈相关关系,从而可测定试样中的锌离子含量。本方法不需要底物转变完全,与终点测定法相比,可减少测定时间并节省酶量。     

Determination of Formaldehyde Traces in Fabric and in Indoor Air by a Kinetic Fluorimetric Method

A simple and sensitive kinetic fluorimetric method is reported for the determination of trace amount of formaldehyde. The proposed method is based on the catalytic effect of formaldehyde on the oxidation reaction of rhodamine B with potassium chlorate in sulfuric acid solution. Formaldehyde in the range of 0.020-0.340 µg/mL can be determined with a limit of detection of 5.73 ng/mL. The method has been used to determine trace formaldehyde in fabric and in indoor air. The results thus obtained show good agreement with those determined by acetyl acetone method.     

表面活性剂增敏动力学光度法测定尿液中的微量SCN-

在pH 11.4的NH3-NH4Cl缓冲溶液中,阳离子表面活性剂溴代十四烷基吡啶(TPB)对硫氰酸根阻抑高碘酸钾氧化间甲酚紫的褪色反应具有明显的增敏作用,据此建立了动力学光度法测定微量SCN-的新方法,该方法的线性范围为0.04～0.72 μg/mL,检出限6.74×10-3 μg/mL.可用于测定吸烟和非吸烟者的尿液中的微量SCN-.     

动力学荧光分析法测定间苯三酚的研究

基于在稀H2SO4介质中,痕量间苯三酚对高碘酸钾氧化罗丹明B具有显著的催化作用,使溶液的荧光猝灭,建立了动力学荧光法测定间苯三酚的新方法。方法的线性范围为0.80~800.0μg/L,检出限为0.40μg/L。本法用于针剂中的间苯三酚含量的测定,结果满意。     

双波长双指示剂催化光度法测定铜的研究

研究了在pH 4.0的HAc～NaAc缓冲介质中,利用痕量铜(Ⅱ)催化过氧化氢氧化罗丹明B和亚甲基蓝褪色的指示反应,通过测量540 nm和660 nm下,催化体系和非催化体系吸光度的变化,建立了双波长双指示剂催化动力学光度法测定痕量铜的新方法.方法的线性范围为0.00080～0.048μg/mL,检出限为4.0×10~(-11) g/mL.方法可用于水中铜的测定.     

Kinetic spectrophotometric determination of hydrazine

A sensitive kinetic method for determining low levels of hydrazine has been described. The method is based on the measurement of the rate of the reaction between hydrazine and Mo(VI) in the presence of hydrochloric acid. The redox reaction was monitored spectrophotometrically at 710 nm. The variable-time and fixed-time methods were used. The calibration graph was linear for hydrazine concentrations of 1.0 × 10⁻⁴-1.4 × 10⁻² M, using the fixed-time method of analysis. The method is simple, rapid, precise, sensitive and widely applicable.     

动力学抑制光度法测定氨三乙酸

氨三乙酸在分析化学中常作为配位滴定剂和掩蔽剂,在催化动力学分析中常作为活化剂。常量的氨三乙酸的测定已有工业化方法,微量氨三乙酸的测定方法极少。酸性和沸水浴条件下,微量的氨三乙酸对高碘酸钾氧化偶氮胭脂红B褪色的反应具有显著的抑制作用,据此建立     

A simple method for the spectrophotometric determination of atrazine using p-aminoacetophenone and its application in environmental and biological samples

A spectrophotometric method is described for the determination of the widely used herbicide, atrazine. Atrazine reacts with pyridine and forms a quaternary halide which adds a hydroxyl group in the presence of alkali to form a carbinol base. The heterocyclic ring of the resulting carbinol breaks forming a glutaconic dialdehyde which is subsequently coupled with p-aminoacetophenone (PMP) to form a yellow orange polymethine dye. Beer's law is obeyed in the range 0.16–1.6 ppm of atrazine at 470 nm. The method is sensitive and free from the interference of most of the foreign species. The analytical parameters have been optimised and the method has been successfully applied to the determination of atrazine in various environmental and biological samples.     

KBrO3-溴酚蓝体系催化光度法测定微量甲醛

在室温及H2SO4介质中, 基于甲醛对KBrO3氧化溴酚蓝有显著的促进作用, 建立了测定微量甲醛的动力学催化光度法. 方法的线性范围为0.70～11.0 μg/mL, 检出限为0.015 μg/mL. 用该方法对某实验室废水中甲醛含量进行了测定, 结果满意.