人发中铬的分光光度测定法

Determination of Chromium in Human Hair by Spectrophotometry

目的建立以淀粉为显色剂的测定人发中铬的分光光度法。方法用(NH4)2S2O8将人发中总铬氧化成六价铬(Cr6+),在酸性介质中,Cr6+将KI氧化为I-3,I-3与淀粉生成蓝色化合物,其化合物的最大吸收波长在590nm。结果人发中铬的含量为8.46～29.56μg/g,最低检出限为0.02μg/ml,线性范围为0.02～1.0μg/ml,变异系数为3.3%,加标回标率为94.8%～104.5%。结论该法用于人发中微量铬的测定快速、准确、简便。

Objective To study the determination of chromium in human hair by spectrophotometry using starch as color agent. Methods The total chromium(Cr)in human hair was oxidized by (NH4?雪2S2O3 into Cr6+,which could oxidize KI to form I-3 in acid medium. I-3 reacted with starch to form a blue colored complex,which revealed the maximum absorption peak at 590 nm. Results The contents of Cr in human hair were 8.46-29.56 μg/g.The lowest detection limit and linear range were 0.02 and 0.02-1.0 μg/ml respectively.The coefficient of variation and standard material-added recovery rates were 3.3% and 94.8%-104.5% respectively. Conclusion This methods was rapid,accurate and convenient for the determination of chromium in human hair.