血清中微量镉的离心光度法测定研究

Determinatin of Trace Cadmium in Serum by Centrifugation and Photometry

研究一种超高灵敏直接测定血清中微克级钢的新分析方法──离心光度法．在Ｃｄ－Ｂｒ－ＲＢ体系中缔合物表观摩尔吸光系数ε５６０＝５．０６×１０８Ｌ·ｍ－１·Ｃｍ－１，Ｃｄ２＋的浓度在１．０×１０－９～１０．０×１０－９ｍｏｌ·Ｌ－１范围服从Ｂｅｅｒ定律．本法用于分析测定人体血清样品中Ｃｄ２＋，得其含量为１．８７×１０－１１ｍｏｌ·Ｌ－１，变异系数为４．２％（ｎ＝５）．

For determining serum cadmium of ppb level,a highly sensitve method of centrifugation and photometry is applied. In the cadmium-bromide-rhodamine B system, the associate shows a molar absorption coeffiient of 5. 06 ×108 L. mol-1. cm-1 at 560 nm. Beer'slaw is obeyed by cadmium in the concentration range of 1. 0 × 10-9～1. 0 × 10-9md· L-1.The interference of coexisting ions is inspected. The method is successsufully applied to thedetermination of serum cadmium in a content of 1. 87 × 10-11mol. L-1,with a variation coefficient of 4.2%.