微波消解-电感耦合等离子体质谱法测定小麦中的8种元素

目的利用微波消解-电感耦合等离子体质谱法测定小麦中Pb、Cd、As、Cr、Se、Ni、Al、Cu的含量。方法样品经过微波消解后,用ICP-MS法同时测定小麦中Pb、Cd、As、Cr、Se、Ni、Al、Cu的含量,以45 Sc、72Ge、103Rh、209Bi作为内标元素采用电感耦合等离子体质谱法测定,用标准曲线法进行定量。结果小麦中Pb、Cd、As、Cr、Se、Ni、Al、Cu的回收率在95.6%~106.8%,线性相关系数(r)≥0.9995,Pb、Cd、As、Cr、Se、Ni、Al、Cu的检出限分别为0.0049μg/L、0.0023μg/L、0.012μg/L、0.016μg/L、0.026μg/L、0.0099μg/L、0.0070μg/L、0.0027μg/L;生物成分分析标准物质(小麦)的各元素的测定结果均在标准值不确定度范围内;同时对3份小麦样品进行连续6次测定,各元素的相对标准偏差(RSD)≤5%。结论本法线性范围宽、抗干扰能力强、测定周期短,完全满足分析的要求,适用于日常样品的检测。

Determination of 8 elements in wheat by inductively coupled plasma mass spectrometry with microwave digestion

Objective To determine the contents of Pb,Cd,As,Cr,Se,Ni,Al,Cu in wheat by microwave digestion-inductively coupled plasma mass spectrometry.Methods After microwave digestion,the contents of Pb,Cd,As,Cr,Se,Ni,Al,Cu in wheat was determined by ICP-MS method,45 Sc,72Ge,103Rh,209Bi were used as internal standard elements to determine by ICP-MS method,and quantitative analysis by standard curve method.Results The recovery rates of Pb,Cd,As,Cr,Se,Ni,Al,Cu in wheat were within 95.6%-106.8%,and the linear correlation coefficient(r)were greater than or equal to 0.9995,and the detection limits of Pb,Cd,As,Cr,Se,Ni,Al,Cu were 0.0049μg/L,0.0023μg/L,0.012μg/L,0.016μg/L,0.026μg/L,0.0099μg/L,0.0070μg/L,0.0027μg/L.The determination of each element of the standard substance for biological composition analysis(wheat)was within the range of uncertainty of the standard value.Six successive assays were performed on three wheat samples,and the relative standard deviation(RSD)of each element was less than or equal to 5%.Conclusion The method has a wide linear range,a strong anti-interference ability,and a short determination period.It fully meets the requirements of analysis,and is suitable for routine sample testing.