石墨炉原子吸收光谱法测定食品中铬的方法学验证

Methodological validation of determination of chromium in food by graphite furnace atomic absorption spectrometry

采用微波消解、湿法消解、高压消解和干法灰化4种前处理方式消解样品,加入基体改进剂消除干扰,利用石墨炉原子吸收光谱法测定食品中的铬。试验结果表明,在铬的吸收波长为357.9 nm时,采用4种前处理方式所测结果的回收率差异无统计学意义(F=1.081,P>0.05)。石墨炉原子吸收光谱法得到方法检出限为0.0018 mg/kg,定量限为0.006 mg/kg,线性范围为0μg/L~20.0μg/L,加标回收率在94%~104%范围内,重复性试验和精密度试验相对标准偏差均小于5.3%。该方法准确、可靠,灵敏度、准确度、精密度高,适于食品风险监测中对铬元素的测定。

In this experiment,the samples were digested by microwave digestion,wet digestion,high-pressure digestion and dry ashing.The matrix modifier were added to eliminate interference,and determine chromium in food by Graphite Furnace Atomic Absorption Spectrometry.The results showed that there was no significant difference(F=1.081,P>0.05)in the recoveries of the four pretreatment methods when the absorption wavelength of chromium was 357.9 nm.The detection limit of the method obtained by graphite furnace atomic absorption spectrometry was 0.0018 mg/kg and the quantitative limit was 0.006 mg/kg.The linear range was 0μg/L~20.0μg/L,the recovery was 94%~104%,and the relative standard deviation of repeatability test and precision test was less than 5.3%.Therefore,the method is accurate,reliable,sensitive,accurate and precise,and is suitable for the determination of chromium in food risk monitoring.