直接进样测汞法测定不同粒径固体食品样品中总汞差异性分析

Differential analysis of total mercury in solid food samples with different particle sizes by direct injection mercury determination

中文关键词:  直接测汞法  总汞  粒径  均匀性

英文关键词:direct mercury determination  total mercury  particle size  uniformity

中文摘要:

      目的 比较直接进样测汞法对不同粒径的固体食品样品中总汞测定结果的差异性, 考察其对固体样品粒径的要求。方法 取不同粒径的固体食品样品于镍舟上, 直接进样测定, 采用2种不同基质的有证标准物质进行质量控制, 用统计学方法及相对均匀度因子(homogeneity factor, HE)进行比较分析。结果 实验过程中2种不同基质的有证标准物质的测定值均在标准值范围内, 表明测定的准确性。未过筛组大米均匀度较差, 而食用菌A均匀度较好可全部通过40目筛, 即粒径选择均在≤425 μm (或筛孔≥40目)时总汞含量的测定结果无显著性差异(P>0.05), 且不同品牌测汞仪测定结果具有较好的一致性。结论 直接进样测汞法测定固体食品样品的方法简单可靠, 但因对样品均匀性有较高的要求, 需样品粒径≤425 μm (或筛孔≥40目)时才能保证测定结果的准确性。

英文摘要:

      Objective To compare the difference of the direct mercury injection method for the determination of total mercury in solid food samples with different particle sizes and to investigate its requirements for the particle sizes of solid samples. Methods Solid food samples with different particle sizes were directly injected into nickel boat for determination. Two kinds of certified reference materials with different matrices were used for quality control. Statistical methods and relative homogeneity factor (HE) were used for comparative analysis. Results During the experiment, the measured values of the certified reference materials of the 2 kinds of different substrates were all within the standard value range, indicating the accuracy of the measurement. The uniformity of rice in non sieving group was poor, while that of edible fungus A was good, which could all pass through 40 mesh sieve, that was, when the particle size selection was less than or equal to 425 μm (or the sieve≥40 mesh), there was no significant difference in the determination results of total mercury content (P>0.05), and the determination results of different brands of mercury meters had good consistency. Conclusion The direct sample mercury measurement method is simple and reliable for solid food samples. However, due to the higher requirements for sample uniformity, the accuracy of the measurement results can only be guaranteed when the sample size is less than or equal to 425 μm (or the sieve is more than 40 mesh).