新试剂三氯偶氮氟胂分光光度法测定热镀锌合金中微量铈

Spectrophotometric determination of trace cerium in hot-dipping zinc alloy with a new reagent trichloro fluoroarsenazo

合成了新试剂三氯偶氮氟胂(简称TC-FAsA)并研究了其与锌合金中微量铈的显色反应.在强酸性体系中铈与TC-FAsA形成蓝紫色络合物,其最大吸收波长为620 nm,表观摩尔吸光系数ε=1.15×105.25 mL溶液中,铈的线性范围是0～25μg.该法用于锌合金或中间锌合金材料中微量铈的测定,相对标准偏差小于3.5%.

A new reagent trichloro fluoroarsenazo（TC-FAsA） is synthesized, and a simple and rapid spectrophotometric method for the determination of trace cerium in hot-dipping zinc alloy with the reagent has been studied. In the strong acid medium, cerium reacts with TC-FAsA to form a stable violet-blue complex, which shows maximum absorption at 620 nm with a apparent molar absorptivity of 1.15×10^5 L·mol^-1·cm^-1. Beer＇s law is obeyed in the range of 0 - 25 μg/25 mL for cerium. This method has been used for the determination of trace cerium in zinc alloy with satisfactory results.