摘要
目的探讨微波消解-石墨炉原子吸收法测定食品污染物铅镉的含量。方法采用微波消解技术,在阶梯升高温度和加热功率条件下,用硝酸和过氧化氢彻底消解样品,消解后的样品用石墨炉原子吸收分光光度法测定铅镉。结果铅浓度在0～20.0μg/L、镉浓度在0～10.0μg/L范围内呈良好的线性关系,相关系数铅r=0.9995,镉r=0.9997;最低检出限铅为5.0μg/kg,镉为0.10μg/kg;相对标准偏差铅<5.4%,镉<7.8%;回收率铅镉都在90.0%～105.0%之间。检测4类食品240份样品,其中大米(面粉)、猪肝(猪肾)、水产品、干食用菌铅合格率分别为86.5%、77.5%、81.5%、87.5%,镉合格率分别为82.0%、76.5%、90.0%、88.0%。结论该方法能够满足食品污染物中铅镉的分析要求。
Objective To investigate the microwave digestion-graphite furnace atomic absorption spectrometry for the determination of lead and cadmium in contaminated foods.Method Using microwave digestion technique,under the conditions of step elevating temperature and heating power,food samples were decomposed completely by nitric acid and hydrogen peroxide;then the lead and cadmium were determined by graphite furnace atomic absorption spectrometry.Results There is a good linear relationship at the concentration of 0-20.0 μg /L for lead and at 0-10.0 μg /L for cadmium;the correlation coefficient of lead is 0.999 5 and that of cadmium is 0.999 7;the detection limit is 5.0 μg /kg for lead and is 0.10 μg /kg for cadmium;The relative standard deviation for lead is less than 5.4%,and that for cadmium is less than 7.8%;the recovery for lead is 90.0%-105.0%,and that for cadmium is 90.0%-105.0%.The pass rates for lead in 240 food samples in four categories,including rice （flour）,liver （pig kidney）,aquatic products and dried mushroom,were 86.5%,77.5%,81.5% and 87.5%,respectively;and that for cadmium were 82.0%,76.5%,90.0% and 88.0%,respectively.Conclusion The method can meet the requirements for the analysis of lead and cadmium in contaminated foods.
出处
《中国食品卫生杂志》
北大核心
2010年第5期418-420,共3页
Chinese Journal of Food Hygiene
关键词
食品污染物
铅
镉
微波消解
石墨炉原子吸收
Food Contaminants
Lead
Cadmium
Microwave Digestion
Graphite Furnace Atomic Absorption
