溴酸钾氧化2,4-二氯苯基荧光酮褪色反应动力学光度法测定痕量锡(英文)

Kinetic spectrophotometric determination of trace tin based on oxidation of p-CPF with KBrO_3 in microemulsion after separation and enrichment by SDG

基于弱酸介质中，在非离子表面活性剂微乳液存在时，痕量锡（Ⅳ）催化KBrO3氧化2，4-二氯苯基荧光酮（P-CPF）的褪色反应，建立了测定痕量锡（Ⅳ）的动力学光度法。方法 检出限为0．012μg／L，线性范围为0．0～1．0μg／L。结合巯基葡聚糖凝胶分离富集，实现了样品中痕量锡（Ⅳ）的测定。方法用于环境水样中锡（Ⅳ）的测定，相对标准偏差为2．3％～4．5％，加标回收率为101．3％～105．0％，结果 与原子吸收法测定值相符；用于岩石样品中锡（Ⅳ）的测定，结果与认定值相符。

A catalytic spectrophotometry for the determination of trace Sn（Ⅳ） based on its catalytic effect on discoloring reaction of oxidation of 2,4-dichlorophenylfluorone （p-CPF） with potassium bromate in weak acid solution and in the presence of microemulsion medium is described. The above reaction is followed spectrophotometrically by measuring the decrease in the absorbance at 530 nm for the catalytic reaction of p-CPF. Under optimum conditions, the calibration graph is linear in the range of 0.0-1.0μg/L of Sn（Ⅳ）. The detection limit is 0. 012 μg/L. Combined with sulphydryl dextrane gel （SDG） separation and enriching, the method has been successfully applied to the determination of Sn（Ⅳ） in environmental water with the relative standard deviation of 2. 3%-4.5% and the recovery of 101.3%-105.0 % , and the results are in good agreement with those provided by AAS method. The method has also been successfully applied to the determination of Sn（Ⅳ） in geological samples, and the results are in good agreement with the certified values.