不同前处理方法对原子荧光法测定食品中总砷结果的影响

Study on impact of different pretreatment methods on total arsenic analysis results by atomic fluorescence spectrometry in food specimens

目的 了解不同前处理方法对原子荧光法测定食品中总砷结果的影响.方法 对氢化物-原子荧光法测定食品中总砷的前处理方法进行研究,探讨干法灰化法、湿法消解法、微波消解法、硝酸预处理-干灰化法4种前处理方法对原子荧光法测定食品中总砷测定结果的影响.结果 在最佳条件下,分析方法的RSD为1.2％～3.8％（n=11）,线性范围为0～150μg/L,相关系数r=0.999 9;在取样量为2.0g时,方法的检出限为0.004 7 mg/kg.结论 硝酸预处理-干灰化法适用于食品特别是富含有机砷的食品中总砷的测定,传统干灰化法、微波消解和湿消解法适用于样品中砷存在形式比较简单的食品样品.

Objective To study the influence of different pretreatment methods on total arsenic analysis results by hydride generation-atomic fluorescence spectrometry in food specimens. Methods Dry ashing method,wet digestion, microwave digestion and nitric acid-dry ashing method were used for pretreatments of food specimens, the total arsenic in specimens were analyzed by atomic fluorescence spectrometry. Results were compared to evaluate the impact of different pretreatment methods. Results Under optimized condition, the relative standard deviation of analytical methods were l. 20%- 3.80% （n= 11）. The linear range was 0-150 μg/L ,r=0. 999 9. The detection limit was 0. 004 7 mg/kg in 2 g of food specimen. Conclusion nitric acid-dry ashing method was a suitable pretreatment method for determination of total arsenic in food specimens,especially food rich in organic arsenic.