大米中硒及其潜在伴生元素的含量测定与风险评估

Determination and Risk Assessment of Selenium and Its Potential Associated Elements in Rice

本文建立了一种同时测定大米中26种元素的ICP-MS方法,对市售的52批次富硒大米和52批次普通大米中硒的潜在伴随元素情况进行了多元素分析研究,旨在为明确大米中硒的伴生元素机制和减少富硒大米膳食风险提供研究参考。结果表明,富硒大米和普通大米中的各元素含量水平存在较大差异,市售富硒大米的硒含量水平整体不高,存在总硒含量不符的情况,市售普通大米存在一定水平的硒,但总硒含量的整体水平较低,有部分大米总硒含量达到了富硒大米硒含量标准。相较于普通大米,发现富硒大米的Cr、Pb、Cd、Sr、Sb、As、Hg和V这8种元素含量排序有所变化,其中,Cr、Pb、Cd和Hg 4种元素含量与Se同步正增长,且差异化程度较高,可初步确定为Se的潜在伴生元素。经进一步显著性分析,可确定在富硒大米中,Se的主要伴生元素为Cd。经对富硒大米中的Cd含量进行判断,均符合国家限量标准。

In the present study, an ICP-MS method was established for simultaneous determination of 26 elements in rice. The potential concomitant elements of selenium in 52 commercial selenium-rich rice and 52 batches of ordinary rice were studied by multi-element analysis, to provide research reference for determining the mechanism of selenium concomitant elements in rice and reducing dietary risk of selenium-rich rice. Results revealed that there was bigger difference level of each element content in selenium-rich rice and normal rice. The selenium content of selenium-rich rice sold overall level was not high, and there were some total selenium contents failing to meet the label. There was a certain level of selenium in normal rice sold, but the overall level of total selenium content was low, there were some rice total selenium contents reached the selenium-rich rice selenium content standards. Compared with normal rice, it was found that the contents of Cr, Pb, Cd, Sr, Sb, As, Hg and V in selenium-rich rice changed in order. Among them, the contents of Cr, Pb, Cd and Hg in selenium-rich rice increased synchronously with high differentiation degree, which could be preliminarily identified as potential associated elements of Se. Further significance analysis indicated that Cd was the main associated element of Se in selenium-rich rice. The content of Cd in selenium-rich rice was judged to be in line with the national limit standard.