Lan Guanyu, Li Xue, Yao Jijun, Yu Xiaofeng, Liu Qinghai, Qiu Cheng, Mao Xuefei
Institute of Agricultural Product Quality Standard and Testing Research, Tibet Academy of Agricultural and Animal Husbandry Sciences, Lhasa, Tibet, China.
Institute of Quality Standard and Testing Technology for Agro-Products, Key Laboratory of Agro-food Safety and Quality, Ministry of Agriculture and Rural Affairs, Chinese Academy of Agricultural Sciences, Beijing, China.
Front Nutr. 2023 Jun 7;10:1201801. doi: 10.3389/fnut.2023.1201801. eCollection 2023.
Rapid, sensitive and simultaneous determination of trace multi-elements in various plant food samples such as grain, oilseed, vegetable and tea is always a challenge thus far. In this work, a rapid determination method for Se, Cd, As and Pb in food samples by inductively coupled plasma mass spectrometry (ICP-MS) using slurry sampling electrothermal vaporization (SS-ETV) was developed. To improve the analytical sensitivity and precision as well as eliminate the memory effect, a gas turbulator line and signal delay device (SDD) were for the first time designed for the graphite furnace (GF) ETV coupled with ICP-MS. The signal acquisition parameters of ICP-MS, ashing and vaporization conditions, and the flow rates of carrier gas and gas turbulator were investigated for Se, Cd, As and Pb in food samples. Under the optimized conditions, the limits of determination (LODs) for Se, Cd, As and Pb were 0.5 ng g, 0.3 ng g, 0.3 ng g and 0.6 ng g, respectively; the limits of quantification (LOQs) for Se, Cd, As and Pb were 1.7 ng g, 1.0 ng g, 1.0 ng g and 1.9 ng g, respectively; linearity () in the range of 1 to 4,000 ng g was >0.999 using the standard addition method. This method was used to analyze 5 CRMs including rice, tea and soybeans, and the concentrations detected by this method were within the range of the certified values. The recoveries of Se, Cd, As and Pb in plant food matrices including grain, oilseed, celery, spinach, carrot and tea samples were 86-118% compared to the microwave digestion ICP-MS method; and the relative standard deviations (RSDs) were 1.2-8.9% for real food sample analysis, proving a good precision and accuracy for the simultaneous determination of multi-elements. The analysis time was less than 3 min, slurry preparation time < 5 min without sample digestion process. The proposed direct slurry sampling ICP-MS method is thus suitable for rapid and sensitive determination of Se, Cd, As and Pb in food samples with advantages such as simplicity, green and safety, as well as with a promising application potential in detecting more elements to protect food safety and human health.
快速、灵敏且同时测定谷物、油籽、蔬菜和茶叶等各种植物性食品样品中的痕量多元素，至今仍是一项挑战。在本工作中，开发了一种采用悬浮液进样电热蒸发（SS-ETV）电感耦合等离子体质谱（ICP-MS）法快速测定食品样品中硒、镉、砷和铅的方法。为提高分析灵敏度和精密度并消除记忆效应，首次为石墨炉（GF）ETV与ICP-MS联用设计了气体湍流器管路和信号延迟装置（SDD）。研究了食品样品中硒、镉、砷和铅的ICP-MS信号采集参数、灰化和蒸发条件以及载气和气体湍流器的流速。在优化条件下，硒、镉、砷和铅的测定限（LOD）分别为0.5 ng/g、0.3 ng/g、0.3 ng/g和0.6 ng/g；硒、镉、砷和铅的定量限（LOQ）分别为1.7 ng/g、1.0 ng/g、1.0 ng/g和1.9 ng/g；采用标准加入法，在1至4000 ng/g范围内的线性度（）>0.999。该方法用于分析包括大米、茶叶和大豆在内的5种标准参考物质，该方法检测到的浓度在认定值范围内。与微波消解ICP-MS法相比，谷物、油籽、芹菜、菠菜、胡萝卜和茶叶样品等植物性食品基质中硒、镉、砷和铅的回收率为86-118%；实际食品样品分析的相对标准偏差（RSD）为1.2-8.9%，证明多元素同时测定具有良好的精密度和准确度。分析时间小于3分钟，无需样品消解过程，悬浮液制备时间<5分钟。因此，所提出的直接悬浮液进样ICP-MS方法适用于快速、灵敏地测定食品样品中的硒、镉、砷和铅，具有简单、绿色、安全等优点，在检测更多元素以保障食品安全和人类健康方面具有广阔的应用潜力。
