乳粉中脂肪成分分析标准物质的研制

Preparation of reference material for fat composition analysis in milk powder

研制乳粉中脂肪成分分析标准物质。选择与日常脂肪检测水平相当的乳粉,经过混匀、分装、真空密封、辐照灭菌制备了脂肪成分分析标准物质,按5 g/袋进行包装,共包装800个单元。采用碱水解法,分别从均匀性、长期稳定性、短期稳定性、以及6家实验室联合定值进行考察,联合定值实验室均采用碱水解法测定乳粉中脂肪。对定值结果进行不确定度评定,乳粉中脂肪的质量分数为26.5%,扩展不确定度为0.6%(k=2)。结果表明,该标准物质均匀性、稳定性良好,符合JJG 1006—1994要求,满足日常检测质量控制、定量检测等使用要求。

The reference material for fat composition analysis in milk powder was developed.Milk powder with the same level as daily fat detection was selected for the experiment.After mixing,packing,vacuum sealing and irradiation sterilization,the standard material for fat composition analysis was prepared.It was packed in 5 g/bag with 800 units in total.The experiment was conducted by alkaline hydrolysis method.The uniformity,long-term stability,short-term stability and the joint determination of 6 laboratories were investigated respectively.The joint determination laboratories all adopted alkaline hydrolysis method.Uncertainty of the fixed value results was evaluated.The mass fraction of fat in milk powder was 26.5%with the extended uncertainty of 0.6%(k=2).The results show that the standard substance has good uniformity and stability,conforms to the requirements of JJG 1006-1994,and meets the requirements of daily quality control and quantitative detection.