甲基橙-亮绿体系动力学光度法测定茶叶中痕量铁  

Kinetic Spcectrophotometric Determination of Trace Iron in Tea with Methyl Orange and Light Green System

作　　者：葛笑兰[1] 谢秀娟[1] 张振新[1] 

机构地区：[1]淮北煤炭师范学院化学与材料学院,安徽淮北235000

出　　处：《分析科学学报》2010年第3期367-369,共3页Journal of Analytical Science

基　　金：安徽省教育厅自然科学基金(No.2006KJ163C)

摘　　要：在硫酸介质中,Fe（Ⅲ）对过氧化氢氧化甲基橙和亮绿褪色反应具有强烈的催化作用,通过测定510 nm和640 nm波长下催化体系和非催化体系的吸光度,建立了双波长双指示剂催化动力学光度法测定痕量Fe（Ⅲ）的新方法。最佳实验条件下,测定的线性范围为8.0~200μg/L,检出限为1.12×10-10g/L。对20.0μg/L Fe（Ⅲ）进行12次平行测定的相对标准偏差为0.067%。该方法灵敏度高,体系稳定,具有较好的选择性,用于茶叶中痕量铁的测定,结果满意。A dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace iron in sulfuric acid medium was studied in this paper.It was based on the catalytic effect of iron on the oxidation of methyl orange and light green by hydrogen peroxide.The absorbance of catalytic system and noncatalytic system were measured at 510 nm and 640 nm.Under the optimum conditions,the linear range for the determination of iron was 8.0~200 μg/L.The detection limit was 1.12×10-10 g/L and the relative standard deviation was 0.067% for 20.0 μg/L iron（n=12）.This method has high sensitivity,stability and good selectivity.The method was applied to tea sample with satisfactory results.

关 键 词：铁 催化动力学光度法 甲基橙 亮绿 

分 类 号：O657.32[理学—分析化学]