快速消解-原子荧光光谱法测定大米中总砷  

Determination of total arsenic in rice by rapid decomposition-atomic fluorescen spectrometry

作　　者：袁野 YUAN Ye(Nanchong Agricultural Products Monitoring and Inspection Center,Nanchong 637000,China)

机构地区：[1]南充农产品质量监测检验中心,四川南充637000

出　　处：《化学分析计量》2022年第10期44-48,共5页Chemical Analysis And Meterage

摘　　要：建立快速消解-原子荧光光谱测定大米中砷含量的方法。以硫脲、抗坏血酸的质量浓度均为10 g/L的硫脲-抗坏血酸-盐酸溶液为掩蔽还原剂、10 g/L硼氢化钾溶液溶液为还原剂、盐酸溶液(5+95)为载流,在优化的仪器工作条件下,采用原子荧光光谱法测定,用标准曲线法定量。砷的质量浓度在0.00~10.00 g/L范围内与荧光强度具有良好的线性关系,相关系数为0.9999,方法检出限为0.7 ng/g。用所建方法对大米样品进行测定,加标回收率为92.1%~104.9%,测定结果的相对标准偏差为0.27%~2.35%(n=5);对两种大米有证标准物质进行测定,测定值均在标准值不确定度范围内,相对误差分别为6.7%和8.3%。该方法精密度、准确度均满足分析要求。A method for the determination of total arsenic in rice by rapid digestion-atomic fluorescence spectrometry was established.The thiourea-ascorbic acid-hydrochloric acid solution with the mass concentration of thiourea and ascorbic acid of 10 g/L was used as masking reducing agent,10 g/L potassium borohydride solution was used as reducing agent,and hydrochloric acid solution(5+95)was used as carrier current.Under the optimized working conditions of the instrument,atomic fluorescence spectrometry was used for determination,and the sample was quantified by the standard curve method.The mass concentration of arsenic had a good linear relationship with the fluorescence intensity in the range of 0.00-10.00 g/L,the linear correlation coefficient was 0.9999,and the detection limit of the method was 0.7 ng/g.The method was used to determine the rice samples,the recoveries were 92.1%-104.9%,and the relative standard deviations of the determination results were 0.27%-2.35%(n=5).The two certified reference materials of rice were determined,the measured values were within the uncertainty range of the standard values,and the relative errors were 6.7%and 8.3%respectively.The precision and accuracy of the method meet the analytical requirements.

关 键 词：大米 快速消解-原子荧光光谱法 总砷 

分 类 号：O657.3[理学—分析化学]