催化动力学光度法测定生物样品中的草酸

提出了一种经动力学光度法测定生物样品中草酸的方法。基于在硫酸介质中,草酸能有效地催化重铬酸钾氧化丁基罗丹明Ｂ褪色,当反应温度为６５℃、反应时间１２ｍｉｎ时,非催化反应溶液的吸光度Ａ０和催化反应溶液吸光度Ａ的ｌｎＡ０／Ａ值与草酸浓度在０．２０～１０．０８μｇ／ｍｌ之间存在良好线性关系。反应体系用高浓度ＮａＯＨ终止后室温下可稳定２ｈ以上。催化反应的表观活化能为１３．５３ｋｊ／ｍｏｌ。方法可直接用于菠菜     

动力学分光光度法结合化学计量学同时测定农药杀线威和抗蚜威

本文采用动力学分光光度法结合化学计量学方法对水样中的两种氨基甲酸酯类农药杀线威和抗蚜威进行测定.该方法基于酸性条件下,Cu(Ⅱ)能催化H2O2氧化罗丹明B而使其褪色,杀线威或抗蚜威存在时能使该反应速率降低,而且两者对反应速率的影响存在一定差异.实验对硫酸浓度、Cu(Ⅱ)浓度、罗丹明B浓度、H2O2的质量分数以及温度等条件进行考察.在选定实验条件下,杀线威和抗蚜威测定的线性范围分别为2～16μg·mL-1和1～15μg·mL-1,检测限分别为0.65μg·mL-1和0.41 μg·mL-1.实验采集波长554 nm处和反应时间0～600 s范围内动力学吸光度数据,并分别采用偏最小二乘法(PLS)和主成分回归法(PCR)处理,建立了定量回归模型并对合成样品进行测定以验证模型.该方法可应用于实际水样中杀线威和抗蚜威的同时测定.     

KIO_4－NTA－二苯胺磺酸钠体系催化光度法测定痕量锰（Ⅱ）

本文研究了Ｍｎ（Ⅱ）催化ＫＩＯ＿４氧化二苯胺磺酸钠的显色反应。在ＮａＡｃ－ＨＣｌ介质中，以氨三乙酸作活化剂，当测定波长为５１０ｎｍ时，锰浓度在０～１５０ｎｇ／２５ｍＬ范围内与吸光度呈线性关系。该法已用于测定茶叶、莲子、黄豆等样品中的痕量锰，结果个人满意。     

Selective Kinetic Spectrophotometric Determination of Nitrite in Food and Water

Abstract

A highly selective and sensitive method for the kinetic spectrophothometric determination of sub-microgram amounts of nitrite has been development based on its reaction with Nile blue 2B in acidic medium. The reaction is monitored spectrophotometrically at 595 nm at a fixed time of 4.5 min. The change in absorbance at 595 nm is related to the concentration of nitrite in the range 0.005 - 1.100 μg.ml^?1 The detection limit is 0.001 μg.ml^?1. The relation standard deviation is 1% for 0.020 μg.ml^?1 of nitrite for ten replicate measurements. Most common anions and cations do not interfere. The procedure was applied to the determination of trace amounts of nitrite in sausage and water.     

动力学光度法测定食品中痕量甲醛

基于酸性介质中甲醛抑制KBrO3氧化碱性品红的褪色反应,建立了阻抑动力学光度法测定痕量甲醛的新方法.利用固定时间法优化了试剂浓度、反应时间和反应温度.在所选择的实验条件下,方法的线性范围为0.08～1.0 mg·L-1,检出限为0.015 mg·L-1.该方法用于水发食品中甲醛含量的测定,并进行了加标回收试验,回收率在93%～105%之间.     

催化动力学光度法测定药物和饮用水中痕量铁的研究

本文利用Ｆｅ＾３＋＋对Ｈ２Ｏ２氧化二苯胺碘酸的反应具有催化作用，且在一定条件下显色反应的速度与催化剂Ｆｅ＾３＋的含量成正比的原理，建立了一种痕量铁的分析方法。本文方法的线性范围为０．００８－０．０６４ｍｇ＝Ｌ，相对标准偏差小于５．０％，标准加入回收率为１０１％－１０３％，检出限为０．００６７３ｍｇ／Ｌ。     

催化动力学光度法对食品中痕量元素分析的研究进展

随着人们生活水平的不断提高,食品中痕量元素的含量越来越引起人们的关注.综述了近十年来催化动力学光度法在食品分析中对痕量元素进行测定的研究情况,并对催化动力学光度法在食品分析中的应用前景和研究方向进行了展望.     

动力学光度法测定痕量镉的研究

本研究了氨水介质中，痕量镉阻抑过氧化氢氧化偶氮胂１褪色的新指示反应及其动力学条件，建立了动力学光度法测定痕量镉的新方法，方法检出限为２．７×１０＾－１２ｇＣｄ＾２＋／ｍｌ，测定范围为０－１．０μｇＣｄ＾２＋／２５ｍｌ。     

阻抑动力学光度法测定痕量间二硝基苯的研究

研究发现 ,在硫酸介质中 ,痕量间二硝基苯能灵敏地阻抑 Fe3+催化高碘酸钾氧化甲基兰褪色。研究了该阻抑褪色反应的最佳条件及动力学参数 ,建立了一种测定痕量间二硝基苯的新方法。该法测定线性范围为 0 .0～ 8.0μg/L,检出限为 1 .6× 1 0 - 6 g/L。用于环境水样中间二硝基苯的测定 ,结果满意     

甲苯胺蓝褪色指示反应动力学光度法测定痕量铁

研究了在硫酸介质中 ,痕量铁催化 H2 O2 和 K2 Cr O7联合氧化甲苯胺蓝褪色反应及其动力学条件 ,建立了催化动力学测定痕量铁的新方法。检出限为9.6 6× 10 -9g· m L-1 ,测定的线性范围为 0～ 0 .6μg/2 5 m L。方法已用于矿泉水、莱服子、菊花、大米和花生中铁的测定     

催化动力学光度法测定钌

在磷酸介质中,痕量钌（Ⅲ）对溴酸钾氧化二安替比林对氨基苯基甲烷（DApAM）的显色反应具有明显的催化作用,研究了反应的最佳条件,并测定了一些动力学参数,据此建立了一种测定痕量钌（Ⅲ）的新方法,其检测限为2．10×10－9g／mL,针含量在0－20μg／L内符合比尔定律,方法用于贵金属精矿中痕量钌的测定,结果满意。     

乙基曙红-溴化十六烷基吡啶光度法测定水样中阴离子表面活性剂

在弱酸性的HAC-NaAC缓冲介质中,将溴化十六烷基吡啶(CPB)与乙基曙红(EE)染料溶液混合,加入阴离子表面活性剂(AS),溶液颜色加深,最大吸收波长都在516nm处,且阴离子表面活性剂的浓度与溶液的增色程度呈良好线性关系。在最大吸收波长处,3种阴离子表面活性剂——十二烷基苯磺酸钠(SDBS)、十二烷基磺酸钠(SLS)及十二烷基硫酸钠(SDS)的浓度分别在0~2.05×10-5mol/L、0~2.08×10-5mol/L、0~2.04×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数分别为2.38×104、2.82×104和2.98×104L/(mol.cm),检出限分别为8.42×10-7、4.56×10-7和7.95×10-7mol/L。方法具有较高的灵敏度和良好的选择性,用于不同水样中AS的测定,结果满意。     

Simultaneous Voltammetric Determination of Three Herbicides in Food and Water Samples with the Aid of Chemometrics

Differential pulse stripping voltammetry method(DPSV) was applied to the determination of three herbicides,ametryn,cyanatryn,and dimethametryn.It was found that their voltammograms overlapped strongly,and it is difficult to determine these compounds individually from their mixtures.With the aid of chemometrics,classical least squares(CLS),principal component regression(PCR) and partial least squares(PLS),voltammogram resolution and quantitative analysis of the synthetic mixtures of the three compounds were successfully performed.The proposed method was also applied to the analysis of some real samples with satisfactory results.     

Kinetic Spectrophotometric Determination of Thiols and Ascorbic Acid

Abstract

This paper describes a kinetic spectrophotometric method for the determination of L‐ascorbic acid (AA) and thiols (RSH). Absorbance of Fe(II)‐phen complex formed during the reaction of AA or RSH with Fe(III)‐phen was continuously measured at 510 nm by double‐beam spectrophotometer with flow cell. For determination some thiols, the catalytic effect of Cu²⁺ ions was used. AA and RSH can be determined in concentration ranges from 4.0×10^?6 to 4.0×10^?5 M and from 8.0×10^?6 to 8.0×10^?5 M, respectively. The applicability of the proposed method was demonstrated by determination of chosen compounds in pharmaceutical dosage forms.     

阻抑动力学光度法测定食品中的痕量铜

研究了铜阻抑高碘酸钾氧化玫瑰桃红R的褪色反应 ,建立了阻抑动力学光度法测定痕量铜的新方法 ,找到了最佳试验条件。该法线性范围为 0～ 0 0 0 8μg/mL ,检出限为 0 3 9× 1 0 - 3μg/mL ,应用于食品中铜的测定 ,结果满意     

Simultaneous Spectrophotometric Determination of Zinc and Nickel in Water Samples by Mean Centering of Ratio Kinetic Profiles

The mean centering of ratio kinetic profiles method was used for the simultaneous determination of binary mixtures of Ni(II) and Zn(II) in water samples, without prior separation steps. The method is based on the difference in the rate of the reaction of Ni(II) and Zn(II) with xylenol orange at pH 5.3. The method allows rapid and accurate determination of Ni(II) and Zn(II). The analytical characteristics of the methods for the simultaneous determination of binary mixtures of Ni(II) and Zn(II) were calculated. The linear range was 0.025‐2.400 μg mL^?1 and 0.025‐2.20 μg mL^?1 for Zn(II) and Ni(II), respectively. Interference effects of common anions and cations were studied, and the method was successfully applied to the simultaneous determination of Zn(II) and Ni(II) in water samples.     

Kinetic Spectrophotometric Determination of Total Iron in Natural Water by Flow Injection Analysis Using On-Line Preconcentration

A new flow injection catalytic spectrophotometric method for on-line preconcentration and determination of total iron in natural water is described. The method is based on a combination of iron-catalyzed oxidation of diaminoditolyl by potassium bromate and the use of on-line preconcentration of iron onto 8-hydroxy-quinoline immobilized on silica gel. The corresponding calibration graph is linear over the range of 2.0–110ngmL^–1 for Fe(III) using a time-based technique for 5min preconcentration. The relative standard deviation of 11 measurements of 60ngmL^–1 Fe(III) was 0.67%. The method was applied to the determination of iron in natural water. The results obtained by the proposed method were compared with those obtained by ICP-AES. The t-test showed no significant differences between the two methods at a confidence level of 95%.     

酶催化动力学光度法测定汞

基于醇脱氢酶催化乙醇和氧化型烟酰胺腺呤二核苷酸的反应中，汞离子对于酶催化的抑制作用，通过测定还原型烟酰胺腺嘌呤二核苷酸吸光度的变化率得出其酶促反应速度，对应于汞而制得标准曲线。检出限为0.5μg/L。讨论了pH值和共存离子对测定的影响。本方法具有快速、灵敏、干扰少的优点。     

甲壳素富集固相反射分光光度法测定矿样中的铁

本文研究了一种新的固相分光光度法－固相反射分光光度法。论文从理论上推导出反射吸附值ＡＲ与物质相应的浓度Ｃ的定量关系。并以甲壳素为吸附剂，以铁，邻二氮菲和十二烷基磺酸钠的缔合物为被吸附物，进行了甲壳素相的反射分光光度法研究。     

催化动力学法测定痕量碲的研究

本发现以钯（Ⅱ）作催化剂，碲（Ⅳ）作活化剂，能催化加速次磷酸钠与靛红的褪色反应，建立了一种测定碲的新方法，方法检测限为３．９×１０＾－１１ｇＴｅ（Ⅳ）／ｍｌ，测定范围为０－０．５μｇＴｅ（Ⅵ）／２５ｍＬ，用以测定人发中的痕量碲，获得了满意的结果。