原子荧光法测定食品中铅的介质酸度控制数学模型

Mathematical Model for Controlling Medium Acidity of Using Atomic Fluorescence Spectrometry to Determination of the Content of Lead in Food

构建了采用原子荧光法测定食品中铅含量时控制反应介质酸度的数学模型，根据该数学模型可以协调样品及载流中盐酸的体积分数、硼氢化钾的质量浓度、还原剂中氢氧化钾的质量浓度等反应介质的重要参数，保证铅烷发生的效率。采用该数学模型对2010年度国际弗帕斯（FAPAS）考核样品（辣椒粉）和国家标准物质（茶叶GBWl0016和灌木枝叶GBW07602）中的铅含量进行了测试，测定值的回收率介于98．9％～109．4％之间，取得满意结果，表明该模型可以指导实际应用。

A mathematical model for controlling the medium acidity of using atomic fluorescence spectrometry to determination of the content of lead was formulated. According to the mathematical model, the key parameters of agents were modulated, which included volume fraction of hydrochloric acid in the samples and carrier, mass fraction of potassium borohydride and that of potassium hydroxide in the reducer solution as well. That ensured the efficiency of plumbane generation. Using the mathematical model we tested the lead contents of 2010 FAPAS chilli powder sample and national certified reference matters （GBW 10016 tea powder and GBW 07602 bush branches and leaves powder）, the recoveries of test ranged from 98.9% to 109. 4%, the results were satisfying. That indicated the mathematical model was worth of practice.