Abstract：Rare earth element can react with arsenazo Ⅲ to form a stable blue complex in the HAc-NaAc buffer solution at pH 3, whose maximum absorption wavelength was located at 660 nm.The apparent molar absorptivity was 2.2×104 L·mol-1·cm-1. Beer’s law was obeyed for rare earths(total RE) in mass concentration of 0-1.6 μg/mL. Accordingly, a method for the determination of total RE in lead-free tin-based solder with arsenazo Ⅲ by spectrophotometry was established. The interference of tin was eliminated through volatilization by hydrochloric acid and bromic acid in sulfuric acid solution, while other cations such as bismuth, indium, copper, silver were eliminated by precipitation separation of sodium diethyldithiocarbamate(DDTC) and joint masking of sulfosalicylic acid and ascorbic acid. For determination of total RE between 0.005% and 0.20% in the samples of lead-free tin-based solder, the relative standard deviations(RSDs) were 3.3%-5.6%, and the recoveries of standard addition were 92.0%-103.3%.
石如祥, 张红玲. 偶氮胂Ⅲ光度法测定无铅锡基焊料中稀土总量[J]. 冶金分析, 2014, 34(5): 72-75.
SHI Ru-xiang, ZHANG Hong-ling. Determination of total rare earth in lead-free tin-based solder by spectrophotometry with arsenazoⅢ. , 2014, 34(5): 72-75.
