用Cd(Ⅱ)-PAR-β-CD测定痕量镉

Determination of Cadmium by the Reaction System of Cd(Ⅱ)-PAR-β-CD

基于在硼砂缓冲溶液中Cd(Ⅱ ) -PAR与β -CD的包合反应 ,发展了测定镉的分光光度法 .以试剂空白作参比 ,包合物的最大吸收波长位于 496nm处 ,摩尔吸光系数为 8.0 6×1 0 4 L/ (mol· .cm) ,Cd(Ⅱ )在 0～ 40 0 μg/L的浓度范围内符合比耳定律 .用该体系测定谷物样品中的Cd(Ⅱ ) ,其结果与用原子吸收法所得的结果相当吻合 .

A method for determination of cadmiun based on the inclusion of cadmiun (Ⅱ)-PAR with β-CD in borax solution has been developed.The maximum absorption wavelength of the inclusion compound is 496nm against reagent blank, and its molar absorptivity is 8.06×10 4 L/(mol·cm). Beer′s law is obeyed in the range of 0～400 μg/L cadmiun. The above mentioned system has been used to determine the contents of Cd(Ⅱ) in some grain samples.The results are quite agreeable with those by atomic absorption spectrometry.