赶酸对微波消解-氢化物发生-原子荧光光谱法测定谷物中砷元素的影响  

Effect of Acid Catching on Determination of As in Grain by Atomic Fluorescence with Microwave Digestion-Hydride Generation

作　　者：段旭[1] 韩张雄[1] 白新悦 董亚妮[1] 刘隆[1] DUAN Xu;HAN Zhangxiong;BAI Xinyue;DONG Yani;LIU Long(Provincial Key Laboratory of Mineral Exploration and Utilization,Shaanxi,Xi'an Testing and Quality Supervision,Center for Geological and Mineral Products,Ministry of Land and Resources,Xi'an,Shaanxi 710054,China)

机构地区：[1]陕西省矿产资源勘查与综合利用重点实验室,国土资源部西安矿产资源监督检测中心,西安710054

出　　处：《中国无机分析化学》2018年第6期5-8,共4页Chinese Journal of Inorganic Analytical Chemistry

基　　金：陕西省自然科学基础研究计划项目(2014JM5217)

摘　　要：在利用氢化物发生-原子荧光光谱法测定谷物类样品中砷元素时,硫脲-抗坏血酸的还原效果会受到硝酸含量的影响,试液中硝酸含量过高,会与硫脲-抗坏血酸溶液发生氧化还原反应,降低其还原效率。通过对赶酸时间和赶酸温度进行实验,获得最佳的赶酸条件,结合微波消解技术,利用氢化物发生-原子荧光光谱法测定谷物中的微量砷,结果表明,谷物中砷浓度与荧光强度呈线性关系,线性方程为y=0.002 8x-0.172 8,线性相关系数R2=0.999 3,检出限为1.72ng/g。通过对9份样品进行检测,其相对标准偏差(RSD)在4.3%～7.6%,其准确度相对误差RE均小于±6.5%。经多次检测证实方法较稳定,可用于谷物类样品中砷元素的快速测定。The reduction effect of thiourea-ascorbic acid was affected by the content of nitric acid during the determination of arsenic in grain samples by hydride generation-atomic fluorescence spectrometry.The content of nitric acid in the test solution was too high,and the redox reaction with thiourea-ascorbic acid solution reduced its reduction efficiency.In this study,the best acid catching condition was obtained in the determination of As in grain by the method of hydride formation-atomic fluorescence spectrometry with digestion by microwave through testing the acid catching time and the acid catching temperature.The result showed that the concentration of As in grain is linearly related to the fluorescence intensity,which is in accordance with the equation of y=0.002 8 x-0.172 8(R2=0.999 3).The detection limit is 1.72 ng/g.The relative standard deviation RSD of the 9 samples is in the range of 4.3% to 7.6%,and the relative error(RE)is less than ±6.5%.The method is stable in numerous tests and can be used for the rapid determination of arsenic in grain samples.

关 键 词：赶酸 微波消解 氢化物发生 原子荧光光谱法 砷 谷物 

分 类 号：O657.31[理学—分析化学] TH744.16[理学—化学]