双波长双指示剂催化光度法测定食品中痕量钒  

Determination of Trace Vanadium in Food with Dual-wavelength and Dual-indicator Catalytic Kinetic Spectrophotometry

作　　者：王晨璐 孙登明[1] 朱庆仁[1] 马伟[1] 

机构地区：[1]淮北煤炭师范学院化学系,安徽淮北235000

出　　处：《分析科学学报》2008年第2期205-208,共4页Journal of Analytical Science

基　　金：安徽省高校自然科学基金(2004KJ320;2005KJ140);安徽省绿色化学重点实验室项目基金(KLSF(Ⅰ)07);淮北市科技计划基金资助项目(040145)

摘　　要：研究了在0．2mol／L柠檬酸介质中，利用钒酸根对溴酸钾氧化乙基紫和萘酚绿B褪色反应同时具有强烈的催化作用，通过650nm和720nm波长下测量催化体系和非催化体系的吸光度，建立了一种双指示剂、双波长催化动力学光度法测定钒（Ⅴ）的新方法。最佳实验条件下，测定钒的线性范围为1．00～80．0μg／L，检出限为1．1×10^-10g／mL。对20．0μg／L钒进行12次平行测定的相对标准偏差为2．2％。方法用于面粉和大米中痕量钒的测定，结果令人满意。A dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace vanadium in 0. 2 mol/L citric acid medium was studied. It was based on the catalytic effect of vanadium on the oxidation of ethyl violet and naphthol green B by potassium bromate. The absorbance of catalytic system and uncatalytic system were measured at 650 nm and 720 nm. Under the optimum conditions, the linear range of the determination of trace vanadium was 1.00-80.0μg/L. The detection limit was 1. 1 × 10^-10 g/mL and the relative standard deviation （n = 12） was 2. 2% for 20.0μg/L vanadium. The method was applied to the determination of trace vanadium in flour and rice with satisfactory results.

关 键 词：钒 双波长 双指示剂 催化光度法 乙基紫 萘酚绿B 

分 类 号：O657.32[理学—分析化学]