快速消解-电感耦合等离子体质谱法测定水产配合饲料中的铬、铜、锌、砷、镉、汞和铅

目的 建立快速消解-电感耦合等离子体质谱法(ICP-MS)测定水产配合饲料中的铬(Cr)、铜(Cu)、锌(Zn)、砷(As)、镉(Cd)、汞(Hg)和铅(Pb)的检测方法。方法 用硝酸将样品在聚丙烯快速消解管中消解,通过优化碰撞池气体流量及在线添加内标的方式消除干扰,同时进行了线性、准确度及精密度试验,并应用于质控样品及实际样品的检测。结果 各元素的标准曲线线性良好,相关系数为1.0000,检出限为0.00229 ~ 0.15030 mg/kg,回收率为91.8% ~ 108.2%,相对标准偏差(RSD)为1.0% ~ 7.9%,质控样品测定值在标准值范围内。在市售水产配合饲料中发现2批次Cr含量超标,需对其来源及形态进行深入分析,评估潜在的质量安全及生态安全风险。结论 建立的方法高效准确,可应用于水产配合饲料的检测分析工作。

Determination of chromium, copper, zinc, arsenic, cadmium, mercury and lead in aquatic formula feeds by rapid digestion-inductively coupled plasma mass spectrometry

Objective To establish a rapid digestion-inductively coupled plasma mass spectrometry (ICP-MS) method for the determination of chromium (Cr), copper (Cu), zinc (Zn), arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb) in aquatic formula feeds. Methods The samples were digested in polypropylene fast digestion tubes with nitric acid. To eliminate the interference, internal standard elements were added online and the gas flow of collision/reaction cell was optimized. The linearity, accuracy and precision tests were carried out and the method was applied to the determination of quality control and actual samples. Results The linearity of elements standard curves was good and the correlation coefficients were 1.0000. The limits of detection were 0.00229?0.15030 mg/kg, the recoveries were 91.8%?108.2% and the relative standard deviations were 1.0%?7.9%. The measured values of the quality control samples were within the range of standard values. Conclusion Two batches of Cr content are found to exceed the standard in the commercial aquatic formula feeds, so it is necessary to deeply analyze its source and form, and evaluate the potential risks of quality safety and ecological safety. This method is efficient and accurate, and can be applied to the rapid detection and analysis of aquatic formula feeds.