食品接触塑料中三聚氰胺的检测方法

Method for Detection of Melamine in Food Contact Plastics

采用高效液相色谱的4种方法检测食品接触塑料中三聚氰胺的迁移量。选取线性回归方程、检出限、定量限、正确度、重复性5个因素,综合评价4种方法,同时检测了3种不同塑料材质的食品接触样品三聚氰胺的迁移量。结果表明,4种方法的回收率均在90%~110%之间,相对标准偏差均小于7.5%,方法1检出限较高,方法灵敏度较低;方法2的保留时间短,不易排除假阳性的结果;方法4色谱峰峰形较差;方法3为最佳测试方法,但氨基柱的柱效明显下降。在正常使用情况下,镀铝膜和淋膜纸碗均未迁移出浓度大于0.5 mg/kg的三聚氰胺单体,满足限量要求;密胺塑料餐具在4%乙酸,100℃条件下,易迁移出三聚氰胺单体,其中,有4个样品超过限量要求;样品来自农贸市场和商店的密胺塑料餐具三聚氰胺的检出率较高。

High performance liquid chromatography(HPLC)was used to detect the migration of melamine in food contact plastics by four methods.Five factors including linear regression equation,detection limit,quantitative limit,accuracy and repeatability were selected to comprehensively evaluate the advantages and disadvantages of the four methods.At the same time,the amount of melamine in 3 food contact samples of different plastics was tested.The recoveries of the four methods were between 90%and 110%,and the relative standard deviation was less than 7.5%.The detection limit of method 1 was high and the sensitivity of the method was low.The retention time of method 2 was short,and it was difficult to exclude the false positive.The chromatographic peak shape of method 4 was poor.Method 3 was the best test method,but it is necessary to pay attention to the decreasing column efficiency of amino column.Under normal conditions of use,no melamine monomer with concentration greater than 0.5 mg/kg was removed from both the aluminized film and the coated paper bowl,meeting the limit requirements.Melamine plastic tableware was easy to migrate out of melamine monomer under the condition of 4%acetic acid and 100℃,among which 4 samples exceeded the limit requirement.Samples of melamine plastic tableware from farmers’markets and stores had a high detection rate of melamine.