直接测汞仪测定食品中总汞含量及结果分析

Determination of Total Mercury in Food by Direct Mercury Analyzer

摘要: 目的：运用DMA-80型直接测汞仪，对不同9类食品(谷物及其制品、肉及其制品、食用菌及其制品、蛋及蛋制品、调味品(食用盐)、蔬菜及其制品、乳及乳制品、饮料类(矿泉水)、特殊膳食用食品(婴幼儿罐装辅助食品))进行总汞含量的检测，建立了直接测定国家食品安全标准规定范围固体、液体食品中总汞含量的方法。方法：精确称取经粉粹、切细均匀固体食品适量，液体样品准确吸取一定体积，应用直接测汞仪直接测定样品中总汞含量。结果：经实验条件筛选，直接测汞仪测定食品中总汞，分解时间为2 min，粮食等植物类食品分解温度为650℃，肉类食品分解温度为850℃，在最佳条件下，标准汞含量在0.0~20.0 ng时，有较好的线性关系，呈线性二次方程，y = −0.00702384 + 0.05199620x − 0.00072712x²，相关系数 ≥ 0.999，加标回收率91.0%~102.9%，测定结果的相对标准偏差1.36%~ 2.87%，方法检出限为0.4 μg/kg。结论：该方法与原子荧光光谱法比较差异无统计学意义。本方法操作简便、快捷、准确、灵敏，重复性好，节约大量试剂成本，对环境无污染，适合快速批量直接测定。

Abstract: Objective: To establish rapid determination of total mercury in solid and liquid forms of food, an elemental mercury analyzer (DMA-80) was applied in 9 kinds of food, including grains, meats, edible fungus, eggs, salts, vegetables, milk and dairy products, mineral water, canned food for infants, the analytical results were compared to the commonly used national standard method atomic fluorescence spectroscopy. Methods: Samples did not need special pretreatment and can be used by direct mercury analyzer to determine the total mercury. Results: According to the experimental conditions, the total mercury was determined by direct mercury analyzer, the sample decomposition time was 2 min, the decomposition temperature of grain and other plant foods was 650˚C, and the decomposition temperature of meat was 850˚C. A linearity was obtained over the range of 0.0- 20.0 ng under the optimum conditions, y = −0.00702384 + 0.05199620x − 0.00072712x², the correlation coefficient was greater than 0.999, recovery rate was 91.0%-102.9%, the relative standard deviation of the determination results was 1.36%-2.87%, and the detection limit was 0.4 μg/kg. Conclusions: There was no statistically significant difference compared with atomic fluorescence spectrometry, and the method is convenient, rapid, accurate, sensitive and repeatability, it can save a large amount of reagent cost and it's environmentally friendly, the method was suggested as a rapid method to determine total mercury for inspection of food and agricultural products.