直接测汞仪测定食品中的总汞

Determination of Total Mercury in Food with Direct Mercury Analyzer

目的建立食品中总汞的测定方法。方法对不同类型的食品和膳食样品(主要是谷类、奶粉、鱼类、蔬菜水果等)进行了汞含量的分析测定。采用直接测汞仪,样品无需任何消解,无论固体样品还是液体样品均可用汞原子蒸气在253.65nm处的共振线具有强烈的特征吸收进行测定。结果本方法线性范围:0～1mg/kg,检出限为0.008ng,相关系数(r)优于0.9990,相对标准偏差(RSD)均在5.0%以内。测定美国NIST标准物质牡蛎粉(oyster tissue,NBS1566)、菠菜粉(spinach,NBS1570)和国家标准参考物质鱼肉(GBW10029),测定值均在标准值范围内。采用本方法两次参加FAPAS国际比对,测定结果的Z评分均在0.5之内。结论本方法灵敏度高、简便、快速、准确,便于推广,适用于各类食品中总汞的测定。

Objective To establish a simple, sensitive and accurate method for the determination of total mercury in food and dietary samples （mainly cereals, milk powder, fishes, vegetables and fruits）. Method Direct Mercury Analyzer was applied. The vapor of solid or liquid sample could be analyzed directly at 253.65 nm without any digestion procedures. Results The linear range of this method was 0-1 mg/kg. The detection limit was 0. 008 ng. The linear correlation factor （r） was higher than 0. 9990, and the relative standard deviation （RSD） was less than 5.0%. The results of determining American NIST reference materials, oyster tissue （ NBS 1566） and spinach （ NBS 1570） , and that of our national reference material, fish meat （ GBW 10029） , were all in the scope of standard values. The Z scores of the resuh were lower than 0. 5 in the FAPAS international proficiency test. Conclusion The method is simple, rapid, sensitive and accurate, and is applicable for the demand of analysing total mercury in food and dietary samples.