湿法消解-石墨炉原子吸收光谱法测定大米中的镉

Detection of cadmium in rice by wet digestion-graphite furnace atomic absorption spectrometry

该研究采用湿法消解―石墨炉原子吸收光谱法测定大米中的镉含量,选择了最佳的样品消解剂为硝酸―高氯酸(6∶1),并确定最佳的测定条件为灰化温度550℃、原子化温度1 800℃、基体改进剂为磷酸二氢铵(20 g/L,自动加样2μL)。得到的线性回归方程为:Abs=0.059 231Conc+0.004 671 6,相关系数r=0.999 9,方法检出限为0.3μg/kg,精密度(RSD)为2.55%。该方法不仅能快速有效地测定大米中的镉含量,还具有操作简单、成本低、回收率高、测定结果准确可靠等特点。

The study aimed to detectcadmium in rice by using GFAAS with wet digestion.The digestion and detectionconditions were selected andoptimized. When theoptimal detectionconditions wereobtained as follows：carbonization temperatureof 550℃,atomization temperatureof 1 800℃, matrixmodifier for NH4H2PO4（20 g/L,automatic sample 2μL）,HNO3–HClO4（6∶1） was taken as theoptimum digestion liquid for digesting rice samples.The results showed that the regression equation wasAbs=0.059 231Conc＋0.004 671 6,and thecorrelationcoefficient was 0.999 9.The detection limit and RSDof thismethod were 0.3μg/kg and 2.55%,respectively.Thus,thismethod notonly was a rapid and effective detection technologyofcadmium in rice,but also wascharacterized by simple operation,lowcost,high recovery,accurate and reliable results.