原子吸收法测定猪肝中的铬及前处理方法探讨

Determination of Chromium in Pig Liver by Atomic Absorption Spectrometry and its Pretreatment

目的:针对猪肝的铬元素,建立适宜的样品前处理方法和石墨炉原子吸收光谱法。方法:分别用湿式消解法、微波消解法、密闭压力消解法、干法灰化法四种前处理方法对猪肝样品及猪肝标准物质进行消化,对比消解效果;通过猪肝标准物质的检测结果确定消解方法。结果:在仪器测定参数优化的条件下,在0~20μg/L范围内测定总铬,相关系数(R)为0.999 8,检出限为0.005 mg/kg,精密度(RSD)3.42%。结论:湿式消解法、微波消解法、密闭压力消解法、干法消化法的一般消解程序不适用于原子吸收法测定猪肝中总铬的消解,干法消化法需将灰化温度提高到900℃,猪肝标准物质的测定结果才在不确定度范围内。石墨炉原子吸收光谱法测定铬的方法灵敏度高、准确性好、快速简便,适用于猪肝样品中铬的测定。

Objective:For chromium in pig liver,a suitable method for sample pretreatment and graphite furnace atomic absorption spectroscopy were established.Method:Wet solution,microwave dissopension,closed pressure dissopension and dry ashing were used to digest pig liver samples and pig liver standard.Digestion methods were determined by the test results of the standard substance of pig liver.Results:Under the condition of instrument parameter optimization,the total chromium was measured in the range of 0 to 20μg/L,the correlation coefficient(R)is 0.9998,the detection limit is 0.005 mg/kg,and the precision(RSD)was 3.42%.Conclusion:The general digestion methods of wet dissolving,microwave digestion,closed pressure digestion and dry digestion were not suitable for atomic absorption method to determine the digestion of total chromium in pig liver.Only the ashing temperature was raised to 900℃,the determination results of the standard substances of pig liver were in the uncertainty range.The determination of chromium by graphite atomic absorption spectroscopy was high sensitivity,accurate,fast and simple,so it was suitable for the determination of chromium in pig liver samples.