ICP-OES和ICP-MS测定中日两国大米中27种矿质元素含量

收集了16种中国大米和11种日本大米,经过微波消解或干灰化法处理后,采用电感耦合等离子体发射光谱法(ICP-OES)和电感耦合等离子体质谱法(ICP-MS)测定了其中Al,As,B,Ba,Ca,Cd,Co,Cr,Cs,Cu,Fe,Hg,K,Mg,Mn,Mo,Na,Ni,P,Pb,Rb,S,Se,Sr,Tl,V和Zn等27种矿质元素的含量,并用生物标准参考物质大米(GBW10010)评价了分析方法的准确度。研究结果表明,基于碰撞反应池技术(CCT)的ICP-MS能有效降低一些多原子离子对低m/z元素离子计数的干扰;与日本大米相比,中国大米中Al,S,Sr等元素含量显著偏高,而B,Cd,Cs,Mg,Mo,P,Pb,Zn等元素含量显著偏低(P0.05),采用聚类分析(最小方差法)对矿质元素含量进行处理,可正确判别两国大米。另外,还发现大米中Mg和P含量之间存在很强的线性相关性,相关系数高达0.9552。

Analysis of 27 mineral elements in the rice samples collected from China and Japan by using ICP-OES and ICP-MS

Based on microwave-assisted decomposition and dry ashing methods, the concentrations of Al, As, B, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Se, Sr, T1, V and Zn in sixteen Chinese rice samples and eleven Japanese rice samples were analysed by using ICP-OES and ICP-MS, and a biological standard reference material rice (GBW10010) was used to verify the accuracy and the precision of analytical method. It was demonstrated that ICP-MS equipped with a collision cell technique can be successfully used for reducing polyatomic interferences in the detection of elements with low m/z ratios. Compared with those in Japanese rice samples, the concentrations of Al, S and Sr in Chinese rice samples are significantly high, and the concentrations of B, Cd, Cs, Mg, Mo, P, Pb and Zn in Chinese rice samples are much lower (P < 0.05). The Ward's method of cluster analysis applied to the concentrations of 26 elements except T1 whose concentration is below the detection limit exhibited the ability to effectively differentiate Chinese rice samples from Japanese rice samples. Moreover, it was found that the concentrations of magnesium correlate very well with the concentrations of phosphorus in all rice samples, with the correlation coefficient being as high as 0.9552.