Tian Wei, Liu Yonglin, Wang Songxue, Ye Jin, Liu Hongmei, Wang Yue, Zhou Minghui
Academy of National Food and Strategic Reserves Administration, Beijing 100037, China.
School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266525, China.
Foods. 2022 Dec 7;11(24):3944. doi: 10.3390/foods11243944.
A rapid, accurate, and ecofriendly pretreatment plays an extremely important role prior to ICP-MS for heavy metal analysis. In order to improve the pretreatment efficiency, a high-throughput and automatic magnetic solid-phase extraction of five heavy metals (Cd, Pb, Mn, Cu, and Zn) was carried out by a magnet-controlled pretreatment system with an ecofriendly diluted acid as an extracting agent and carboxyl-functionalized magnetic beads as a pretreatment material. Key conditions, including the pH, adsorption time, and eluent solution, were optimized. The time for purification and enrichment was only 8 min. The adsorption capacities of the carboxyl-functionalized magnetic beads were in the range of 152426 mg g. The preconcentration factor of Cu was 40, and others were 200. In the optimal conditions, the limits of detection for Mn, Zn, Cd, Cu, and Pb by ICP-MS were 3.84, 2.71, 0.16, 11.54, and 6.01 ng L, respectively. The percentage recoveries were in the range of 80110%, and the relative standard deviations were less than 3%. The developed method was in good agreement with traditional standard microwave digestion. Additionally, the designed system could simultaneously process up to 24 samples within 22 min, reducing the time to less than 1 min/sample. Thus, the proposed auto-MSPE-ICP-MS method was successfully applied to analyze five heavy metals in cereals and feeds with a simple operation and high precision, safety, and reliability.
在进行电感耦合等离子体质谱法（ICP-MS）重金属分析之前，快速、准确且环保的预处理起着极其重要的作用。为了提高预处理效率，采用磁控预处理系统，以环保型稀酸为萃取剂、羧基功能化磁珠为预处理材料，对5种重金属（镉、铅、锰、铜和锌）进行了高通量自动磁固相萃取。优化了包括pH值、吸附时间和洗脱液等关键条件。净化和富集时间仅为8分钟。羧基功能化磁珠的吸附容量在152426 mg/g范围内。铜的预富集因子为40，其他元素为200。在最佳条件下，通过ICP-MS测定锰、锌、镉、铜和铅的检出限分别为3.84、2.71、0.16、11.54和6.01 ng/L。回收率在80%110%范围内，相对标准偏差小于3%。所建立的方法与传统的标准微波消解方法吻合良好。此外，所设计的系统能够在22分钟内同时处理多达24个样品，将每个样品的处理时间缩短至不到1分钟。因此，所提出的自动磁固相萃取-电感耦合等离子体质谱法（auto-MSPE-ICP-MS）以操作简单、高精度、安全可靠成功应用于谷物和饲料中5种重金属的分析。
