电感耦合等离子体质谱法测定汞元素校准曲线线性探讨
2020-06-21颜巧丽李悟庆刘天一袁燕平
颜巧丽 李悟庆 刘天一 袁燕平



摘要 按照GB 5009.268—2016电感耦合等离子体质谱法,以大米粉标准物质作为研究对象,以工作曲线作为校准曲线对汞元素的检测进行方法验证,并从方法的线性范围、工作范围、校准曲线质量检验3个方面进行初步研究。结果表明,汞元素在0~0.6、0~1.0、0~1.5、0~2.0 ng/mL 4个浓度范围具有良好的线性关系,0~1.0 ng/mL的浓度下,校准曲线能够顺利通过质量拟合检验;按照GB 5009.268—2016标准用电感耦合等离子体质谱检测大米粉中的汞元素,方法检出限为0.000 9 mg/kg,相对误差为2.3%,相对标准偏差为0.1%,均符合测试要求。
关键词 汞;ICP-MS;校准曲线检验;方法验证
中图分类号 O657.63文献标识码 A
文章编号 0517-6611(2020)11-0202-03
Abstract Using the rice powder standard material,according to GB 5009.268-2016 inductively coupled plasma mass spectrometry, the method of mercury element detection was verified by the working curve as the calibration curve. A preliminary study was carried out from three aspects: the linear range of the method, the working range and the quality of the calibration curve. The results showed that mercury had a good linear relationship in the concentration range of 0-0.6, 0-1.0, 0-1.5 and 0-2.0 ng/mL.At the concentration of 0-1.0 ng/mL, the calibration curve could pass the mass fitting test smoothly.The mercury content in the rice powder was detected by inductively coupled plasma mass spectrometry according to the method of GB 5009.268-2016. The detection limit was 0.000 9 mg/kg, and the relative error was 2.3% ,the relative standard deviation was 0.1%, met the test requirements.
Key words Mercury;ICP-MS;Calibration curve test; Methods validation
有害金屬超标是我国粮食污染物之一。我国食品安全标准GB 2762—2012《食品中污染物限量》规定,稻谷(以糙米计)、大米、糙米汞(以Hg计)含量不得超过0.02 mg/kg。目前检测大米重金属的方法有原子荧光光谱法[1]、原子吸收光度法[2]、电感耦合等离子体质谱法[3-6]等。其中,电感耦合等离子体质谱(ICP-MS)灵敏度高、线性范围宽,且能够同时测定多种元素,已经成为痕量分析的首选工具,被越来越多的环境和食品检测实验室使用。汞元素具有较强的记忆效应,行业内测试汞元素大多数还是推荐采用原子荧光法。该研究以国家二级标准物质大米作为研究对象,以ICP-MS为检测手段,以工作曲线作为校准曲线,按照GB 5009.268—2016法对汞元素的检测进行方法验证,并分析校准曲线的制作对试验结果的影响,及校准曲线质量检验对检验结果的重要性。
1 材料与方法
1.1 试验……
