固体直接进样-测汞仪测定不同种类茶叶中的汞含量  

Determination of Mercury Content in Different Types of Tea by Solid Direct Injection Mercury Analyzer

作　　者：陈强 万茜 龚娴 CHEN Qiang;WAN Qian;GONG Xian(Jiangxi Province Ecological Environmental Monitoring Center Nanchang,Nanchang 330038,China)

机构地区：[1]江西省南昌生态环境监测中心,江西南昌330038

出　　处：《现代食品》2023年第21期155-158,共4页Modern Food

摘　　要：目的:建立固体进样-直接测汞仪测定茶叶中汞的方法,并利用该方法调查市售茶叶中的汞含量。方法:通过对茶叶样品进行热分解,样品中的汞释放并经金汞齐化管富集,加热破坏金汞齐后,采用冷原子吸收测汞仪对茶叶中的总汞进行分析。通过优化仪器的工作条件,采用长、短双检测池,可以准确测定茶叶中的汞含量。结果:采用冷原子吸收测汞仪测定茶叶中的汞,方法检出限为0.123μg·kg^(-1),对不同实际茶叶样品重复测定6次的相对标准偏差为0.6%~1.1%。将本法应用于茶叶及杨树叶标准物质中汞含量测定,测定值与证书标称值一致,实际茶叶样品测定回收率为97.5%~103.0%。对实际茶叶样品进行湿法消解处理后,采用原子荧光光谱法和热解析冷原子吸收测汞仪进行比对测试,结果表明两种分析方法汞的测量结果之间无明显差异。利用固体进样-直接测汞仪调查江西省市场市售茶叶84份,汞含量为ND~38.7μg·kg^(-1),符合相关标准,THQ值均小于1。结论:本方法准确可靠,市售茶叶比较安全,对人类健康风险较低。Objective:To establish a method for the determination of mercury in tea by solid sampling-direct mercury analyzer,and to investigate the mercury content of commercially available tea by this method.Method:Through the thermal decomposition of the tea sample,the mercury in the sample was enriched by a gold amalgam tube and destroyed by heating,the total mercury in the tea was analyzed by a cold atomic absorption mercury analyzer.By optimizing the working conditions of the instrument and using long and short double detection cells,mercury in tea can be determined directly and accurately.Result:The detection limit of mercury in tea was 0.123μg·kg^(-1) by cold atomic absorption mercury analyzer of thermal desorption,the relative standard deviation was 0.6%~1.1%for different actual tea samples.The method was applied to the determination of mercury content in tea and poplar leaf reference materials.The measured value was consistent with the nominal value of the certificate.The recovery rate of actual tea samples was 97.5%~103.0%.After wet digestion of actual tea samples,atomic fluorescence spectrometry and thermal desorption cold atomic absorption mercury analyzer were used for comparison test.The results showed that there was no significant difference between the measurement results of mercury by the two analytical methods.The solid injection direct mercury analyzer was used to investigate 84 commercially available tea leaves in Jiangxi province.The mercury content was ND~38.7μg·kg^(-1),which met relevant standards.The THQ values were all less than 1.Conclusion:This method is accurate and reliable,and the commercially available tea is safe and has low risk to human health.

关 键 词：直接测汞仪 热分解 茶叶 双检测池 危害评价 

分 类 号：TS207.3[轻工技术与工程—食品科学]