中国大米汞含量研究

Mercury Concentrations in Rice from China

从中国9个省、市或地区的市场采集了303个大米样品,测定了其总汞和甲基汞的含量,评估了我国居民食用大米导致汞暴露的健康风险。大米总汞采用混合酸消解后CVAFS测定,甲基汞采用萃取-反萃取-水相乙基化结合GC-CVAFS测定。结果显示:各地区大米总汞的平均含量为3.6～17μg·kg-1,低于我国食品汞限量标准20μg·kg-1,但江西、江苏、贵州、湖北、湖南和广东等地区有35个样品超过标准规定;甲基汞含量平均为0.97～3.2μg·kg-1,最高含量为18μg·kg-1。初步研究表明,我国的大米总汞和甲基汞对居民健康风险贡献分别为1.7%～12%和1.4%～6.9%。

303 rice samples were collected from the markets in 9 different provinces of China to determine the total mercury（THg） and methylmercury（MeHg） concentrations and to assess the health risk of exposure to mercury from rice consumption for inhabitants in China.THg in the rice samples was measured by cold vapor atomic fluorescence spectrometry（CVAFS） after digested by acid,while MeHg was digested with alkaline-leaching/solvent extraction technique,and analyzed using aqueous-phase ethylation reaction,GC separation and CVAFS detection.The average of THg in rice samples from different provinces varied from 3.6 to 17 μg·kg-1,lower than the nationally permitted level of THg（20 μg·kg-1） in food,but THg in 35 samples from Jiangxi,Jiangsu,Guizhou,Hubei,Hunan and Guangdong provinces exceeded as compared with the national permission.The average of MeHg in rice ranged from 0.97 to 3.2 μg·kg-1,with the highest value being 18 μg·kg-1.The contributions of THg and MeHg from rice for inhabitants in China ranged from 1.7% to 12% and from 1.4% to 6.9%,respectively.