电感耦合等离子体质谱法同时测定食品中的铅、镉和总砷

建立了电感耦合等离子体质谱(ICP–MS)法同时测定食品中的铅、镉和总砷含量的分析方法。样品经消化后直接用ICP–MS分析,采用在线引入混合内标溶液校正基体干扰和仪器的信号漂移。铅、镉、总砷的质量浓度在0~50μg/L范围内与信号强度呈良好的线性,线性相关系数(r)均大于0.999 0。用该方法对标准物质进行测定,分别采用湿法、微波消解法对样品进行处理,两种前处理方式测定值无显著性差异,测定结果的相对标准偏差在0.45%~4.2%之间(n=6),检测结果均在参考值范围内。该方法可同时测定铅、镉和总砷含量,操作简便、重现性好、结果准确可靠,可以满足各种食品中铅、镉和总砷同时测定的要求。

Simultaneous Determination of Pb,Cd and Total As in Foods by Inductively Coupled Plasma-Mass Spectrometry

A method was developed for the simultaneous determination of Pb,Cd,and total As in foods by inductively coupled plasma mass spectrometry （ICP–MS）. Samples were directly determined by ICP–MS after being digested with on-line internal standard to correct the instrument signal drift.The mass concentration of Pb, Cd, As was linear with signal intensity in the range of 0–50μg/L,the linear correlation coefficient （r） was more than 0.999 0. Standard materials were determined by the method, and the sample was treated with wet method and microwave digestion method. The detection results indicated that two kinds of pretreatment method were no significant difference, the detection values were in the reference value range, and the relative standard deviations were 0.45%–4.2%（n=6）. The method can simultaneously determine Pb, Cd, and total As,which is simple in operation, has good reproducibility with the accurate and reliable results. The method can meet the requirement of detection of Pb,Cd and total As in foods.