微波消解-ICP-AES法测定大米和小麦粉中21种无机元素

以电感耦合等离子体原子发射光谱法(ICP-AES)测定山西大同大学食堂大米和小麦粉中21种无机元素的含量。该方法测定各元素的相关系数在0.995 0～0.999 9之间,仪器检出限在0.000 4～0.103 8μg/mL之间,选取Mn,Ca,Mg,K做加标回收实验,回收率在91.57%～105.60%之间,相对标准偏差(RSD)在0.54%～2.50%之间(测定次数n=3),方法快速、准确、可靠。检测发现,所测大米和小麦粉中均含K,Ca,Na,Mg,Fe,Mn,Cu,Zn,Cr,B,P,Si,Li和Se等人体必需的矿质元素;均未检测到Cd,Pb,Co,Ni以及有毒元素Hg和As,但均检测到Al元素,摄入过量会影响Fe,Ca元素的吸收。

Simultaneous Determination of 21 Mineral Elements in Rice and Wheat Flour by ICP-AES with Microwave Digestion

This paper described the simultaneous determination of multi-elements in rice and wheat flour from Datong University canteen by Inductively Coupled Plasma Atomic Emission Spectroscopy(ICP-AES).The linear correlation coefficient of each linear regression equation for the corresponding element were good(0.995 0～0.999 9).The detection limit was between 0.000 4 μg·mL-1 and 0.103 8 μg·mL-1.The proposed method was validated by the added standard method,the recoveries of the method were in the range of 96.6%～105.7%,and each relative standard deviation(n=3) was between 0.54% and 2.50%.This method is simple,rapid and accurate.The results showed that such trademarked rice and wheat were rich in the essential mineral elements(K,Ca,Na,Mg,Fe,Mn,Cu,Zn,Cr,Li,B,P,Si and Se) and didn’t contain the hazardous elements As and Hg,However,Al element had been detected in such rice and wheat.It was suggested that there should have certain restriction in daily intake of such trademarked rice and wheat.