微波消解-同位素稀释-电感耦合等离子体质谱(ID-ICP-MS)法测定紫菜中镉  

Determination of Cadmium in Laver by Isotope Dilution-Inductively Coupled Plasma Mass Spectrometry with Microwave Digestion

作　　者：蔡玮 张世龙 赵博[1] 陈欢欢 逯海[1] 李潇[1] CAI Wei;ZHANG Shilong;ZHAO Bo;CHEN Huanhuan;LU Hai;LI Xiao(National Institute of Metrology,Beijing 100029,China;Jiangxi General Institute of Testing and Certification Donghua Institute of Metrology and Testing,Nanchang,Jiangxi 330031,China)

机构地区：[1]中国计量科学研究院,北京100029 [2]江西省检验检测认证总院东华计量测试研究院,南昌330031

出　　处：《中国无机分析化学》2025年第3期323-329,共7页Chinese Journal of Inorganic Analytical Chemistry

基　　金：国家重点研发计划项目(2016YFF0201106);中国计量科学研究院基本科研业务费资助项目(AKYZZ2429)。

摘　　要：紫菜产品中镉污染超标的报道屡见不鲜,准确高效测定紫菜中的镉含量意义重大。通过探讨硝酸、硝酸+过氧化氢、硝酸+氢氟酸三种体系对测定结果的影响,进一步对硝酸+氢氟酸体系中氢氟酸的加入时间及加入量进行优化,并以GBW08521标准物质对方法进行验证,建立了一种微波消解-同位素稀释-电感耦合等离子体质谱(Isotope Dilution Inductively Coupled Plasma Mass Spectrometry,ID-ICP-MS)法对紫菜中镉定量分析的方法,结果表明,硝酸+氢氟酸体系处理紫菜样品的消解效果最佳,氢氟酸宜在消解前加入,且对于0.2 g的紫菜样品,氢氟酸的添加量为0.5 mL即能使其消解完全。与常规ICP-MS定量方法比,ID-ICP-MS法能有效排除基体效应的影响,测量准确度、精密度良好。ID-ICP-MS法测定GBW08521标准物质的镉含量为5.3 mg/kg,扩展不确定度U=0.1 mg/kg,k=2,与标准值相比,归一化偏差|En|=0.25<1,方法准确可靠。此外,加标回收实验中,不同样品的镉加标回收率均在92.0%~102%,回收效果好。紫菜实际样品分析结果表明,硝酸+氢氟酸消解体系联合ID-ICP-MS法比国家标准方法GB 5009.268—2016更具普适性。方法可作为标准物质中镉含量的定值方法,应用于紫菜等复杂基体中镉含量的高精度分析。The reports of excessive cadmium(Cd) pollution in laver products are of common occurrence,so the accurate and efficient determination of Cd content in laver is of great significance.A method of isotope dilutioninductively coupled plasma mass spectrometry(ID-ICP-MS) with microwave digestion was established for the quantitative analysis of Cd in laver.The effects of three digestion systems(including HNO_3,HNO_3+H_2O_(2) and HNO_3+HF) on the determination results were discussed.The addition time and amount of HF in the HNO_3+HF system were further optimized.And the method was verified using certified reference material(GBW08521).The results showed that the HNO_3+HF system had the best digestion effect on laver samples,and HF should be added before digestion.Furthermore,for 0.2 g amount of laver samples,the addition of 0.5 mL HF could completely digest them.Compared with conventional ICP-MS method,the ID-ICP-MS method could effectively eliminate the influence of matrix effect.And the measurement accuracy and precision of the method were good.The determination of Cd content in GBW08521 reference material by ID-ICP-MS method was 5.3 mg/kg,and the expended uncertainty was 0.1 mg/kg with the coverage factor k=2.Compared with the standard value,the normalized deviation |En| value was 0.25(smaller than 1),indicating that the method was accurate and reliable.In addition,in the spiked recovery experiment,the Cd spiked recoveries of different samples were all between 92.0% and 102%,indicating good recovery effects.The analysis results of actual samples of laver showed that the combination of HNO_3+HF digestion system and ID-ICP-MS method was more universal than the national standard method mentioned in GB 5009.268—2016.This method can be used as the determination method of Cd content in reference materials,and can be applied to high-precision analysis of Cd content in complex matrices such as laver.

关 键 词：紫菜 镉 微波消解 同位素稀释-电感耦合等离子体质谱法 

分 类 号：O657.31[理学—分析化学]