光化学氧化甲基紫2.5次微分极谱法间接测定痕量铁

Indirect Differential Polarographic Determination of Trace Iron

中文关键词:  光催化氧化  微分极谱法  铁  甲基紫  茶叶

英文关键词:Photocatalytic oxidation  differential polarography  Iron crystal violet  tea lerf

中文摘要:

      在稀硫酸介质中及活化剂草酸存在条件下,痕量铁(Ⅲ)对甲基紫光化学褪色慢反应有强烈催化作用,甲基紫的光化学产物于-0.70V处产生一个2.5次微分极谱波.以该产物作指示组分,采用2.5次微分极谱检测技术,研究了利用此体系测定铁的影响因素,建立了一个检出限和测定范围分别为3μg/L和6～300μg/L铁的光化学分析新方法,并用于茶叶分析.

英文摘要:

      Fe(Ⅲ) has strong effect on the photocatalytic oxidation of methyl violet in dilute sulfuric acid medium. The irradiation source was an UV lamp, and oxalic acid was used as the activator. The photochemicl oxidation product of methyl violet exhibits a 2.5 order differential palarographic wave at -0.70V vs. SCE. So this ware was chosen as an indicator for the oxidation reaction. On this ground, a novel photochemical-voltammetric method for the indirect determination of 6～300 μg/L Fe in tea samples was established. The detection limit was 3 μ g/L Fe.