摘要
用三氯甲烷作萃取剂,通过Pb2+和双硫腙的配位显色反应,研究了茶叶中微量铅含量的测定方法。实验结果表明,在pH=10.5的三酸缓冲溶液中,有色溶液的最大吸收波长为510 nm,Pb2+质量浓度在0 mg/L~2.0 mg/L符合朗伯-比尔定律,加标回收率为98.9%~102.2%,重现性较好。本法用于测定茶叶中的Pb(Ⅱ),简单易行、结果可靠。
The determination method of trace lead content in tea was studied by Pb^2+ and diphenylthiocarbazone matching place coloration reaction which uses trichloromethane as extraction agent. The results show that, in pH = 10.5 britton-robinson buffer solution, colouted solution maximum absorbs wavelength being 510 nm, Pb^2+ concentration accords with lambert-beer law within 0 mg/L - 2.0 mg/ L range , add the bid coefficient of recovery is 98.9% - 102.2% , and reappearance is better. This law used for Pb^2+ in determine tea is simple and reliable.
出处
《山西化工》
2012年第5期53-55,共3页
Shanxi Chemical Industry
关键词
茶叶
铅
双硫腙
分光光度法
tea
lead
diphenylthiocarbazone
speetrophotometry