湿法快速消解-原子荧光光谱法测定农产品中汞含量

建立了湿法快速消解-原子荧光光谱仪测定农产品中汞含量的方法。选取大米和芹菜作为实验样品,对消解酸体系(硝酸、硝酸-过氧化氢、硝酸-高氯酸)、消解温度(100、110、120、130、140℃)和消解时间(30、45、60、90 min)等条件进行探讨,确定最佳实验条件,并与常规微波消解效果进行对比。结果表明,优化后的硝酸-高氯酸体系条件下120℃消解30 min,方法在0~2μg/L范围内线性关系良好,相关系数为0.9996,方法检出限为0.001 mg/kg,精密度为2.4%~3.9%。两种消解方法对于大米和芹菜质控样的测定值基本一致,均在质控样范围。相较于常规微波前处理方法,简化了样品前处理流程,提高了工作效率,可为农产品汞含量检测提供可靠的方法支撑。

Determination of Total Mercury in Agricultural Products by Rapid Wet Digestion-Atomic Fluorescence Spectrometry

In order to detect total mercury in agricultural products,a method of rapid wet digestion-atomic fluorescence spectrometry was developed in this study.Rice and celery samples were analyzed by the optimized parameters of acid systems(HNO₃,HNO₃-H₂O₂,HNO₃-HClO₄),heating temperatures(100,110,120,130,and 140℃),and heating times(30,45,60,and 90 min).And then the digestion effect and detection results of optimal pretreatment method were compared with conventional microwave digestion.The results showed that the method of sample digested under HNO₃-HClO₄ digestion at 120°C for 30 min of linear correlation coefficient was 0.9996 in the rang of 0-2μg/L,detection limit was 0.001 mg/kg,and precisions were 2.4%—3.9%.For the rice and celery standard samples,the measured values of two pretreatment methods were within the range of standard samples.Compared with conventional microwave digestion method,the rapid wet digestion method simplifies sample pretreatment process,improves work efficiency,and provides a reliable detection method for the accurate detection of total mercury in agricultural products.