用双毛细管喷雾器和火焰原子吸收微分法测定人发和调味品中的铅

Determination of Lead in Hair and Flavourings by Using Double Capillary Nebulizer and Differentiation in Flame Atomic Absorption Spectrophotometry

在氢化物发生和火焰原子吸收分光光度法中使用的同心双毛细管喷雾器被应用于测定头发、食盐，醋和鱼露中的铅含量．让一根毛细管吸喷１％ＫＢＨ４溶液，另一根吸喷含有１％Ｋ３［Ｆｅ（ＣＮ）６］和 ０．３ｍｏｌ·Ｌ－１ＨＮＯ３的铅溶液．用装有微分放大器的简易型火焰原子吸收分光光度计测量在空气－乙炔焰中产生的原子吸收信号．使方法的灵敏度明显提高．所建立的标准曲线的线性范围为０．０１６－０．５６ｐｐｍＰｂ．当８次测定０．０３２ｐｐｍＰｂ时，相对标准偏差小于４％．

A nebulizer with two concentric capillaries used in hydride genernation and flame atomic absorption spectrophotometry has been applied to the determination or lead content in hair, common salt, vinegar and fish sause. In this paper, one capillary is used for the aspira- tion of the solution or 1% KBH4 and the other for the asporation or lead solution containing 1 %K3(Fe(CN)6] and 0.3mol·L-1 HNO3. The atomic absorption signal produced in air-acety- lene flame is measured by means or a simple name atomic absorption spectrophotometic equipped with a differentiator amplifier. As a result, the sensitivety of the method is enhanced apparently. The linear range of standard curve between 0.016 and 0.56 ppm Pb has been es- tablished. The relative standard deviation is less than 4% when 0.032 ppm Pb is measured 8 times. The advantages or the proposed method are simplicity, rapidity and easy reappearance.