包装食品中胆固醇的实验室分析及其误差的研究

Laboratory Analysis and Its Error for Cholesterol in Prepackaged Foods

目的研究我国实验室对包装食品中胆固醇检测的实验误差。方法根据2000年全国包装食品消费的调查,选择2类(肉类、奶制品类)4种包装食品,在全国的7家实验室进行3次胆固醇的平行样检测,胆固醇检测方法为国家标准方法。结果所有胆固醇检测结果筛查均合格。胆固醇检测精密度为:实验室内相对标准差5.93%～9.10%,实验室间16.79%～34.72%,室内和室间总和为17.91%～35.27%,平均25.78%。胆固醇检测的相对扩展不确定度为35.64%～63.62%,平均47.73%。结论我国实验室对胆固醇的检测误差在35%以内,95%不确定度在65%以内。

Objective To observe the experimental error of cholesterol analysis in prepackaged food from different labs of China. Method According to national prepackaged foods consumption survey results in 2000, 4 prepackaged foods were selected as samples and divided into meat products and dairy products. The cholesterols of samples were analyzed in parallel for three times with national standard methods in seven labs from all the country. Results 100% results were up to grade by Grubbs, Cochran and Dixon screening methods. The accuracy of cholesterol analysis was expressed by RSD. The RSD of inner labs and inter labs were from 5.93% to 9.10% and from 16.79% to 34.72% . The RSD of sum of inner labs and inter labs was from 17.91% to 35.27%, and the RSD of average of inner labs and inter labs was 25,78% , The relative expanded uncertainty of cholesterol detection was from 35.64% to 63.62% （average 47.73%） . Conclusion Cholesterol analysis error was less than 35% from different labs of China, and the 95% uncertainty of analysis was less than 65 % .