热喷雾蒸气发生原子吸收法测定生物样品中的镉

文章采用热喷雾技术,将样品和硼氢化钾引入喷雾器,并在喷嘴处混合发生热雾相反应。生成的蒸气态物质经去溶装置冷却后直接进入T形石英管中用原子吸收法测定。该方法的灵敏度和稳定性较传统气动雾化法有了较大提高，检测限为18 ng·L-1,相对标准偏差为2.1%。用于烟草中镉的测定，回收率为94%～103%。

Determination of Cadmium in Tobacco Using Thermospray-Chemical Vapor Generation-AAS System

A new and sensitive method for the determination of cadmium was developed using thermospray chemical vapor generation AAS system. The sample and KBH4 solutions were introduced into two separate thermospray tubes by peristaltic pumps and then thermosprayed into a reaction tube. The aerosol of the sample and KBH4 were mixed and reacted in the reaction tube, and after gas-liquid separation in a cyclonic spray chamber, the water vapor was removed by a desolvating unit, while the analyte was transferred into the quartz T-cell and determined by AAS. This design improved the stability and sensitivity by thermospray chemical vapor sample introducing technique. The effect of several experimental parameters of the proposed system was optimized. Under the optimized experimental conditions, the detection limits of 18 ng x L(-1) with RSD of 2.1% was obtained for cadmium determination. This method has been successfully applied to the determination of cadmium in tobacco with the recoveries of 94%-103%.