Case and model analysis of between-unit and within-unit homogeneity evaluation for the proficiency test sample of fipronil sulfone in eggs
National Institutes for Food and Drug Control, Beijing 100050, China
Abstract：The within-unit and between-unit homogeneity evaluation of proficiency test sample of fipronil sulfone in eggs was conducted. The detection method involved in the proficiency test was investigated in methodology, and samples were taken within and between units for detection according to the pre-set model. Within-unit homogeneity evaluation was conducted with one-way ANOVA (Analysis of variance) model by using the variance of intra unit test data and variance of method repeatability data. The results showed that the within-unit and between-unit homogeneity of fipronil sulfone meet the requirements. The sources and representativeness of variance in the one-way ANOVA model of between-unit and within-unit homogeneity evaluation was discussed. A within-unit homogeneity evaluation is conducive to mastering the performance of the method involved in proficiency test, confirming the minimum sampling amount of the measurement, identifying the source of the inhomogeneity, and increasing the reliability of the between-unit homogeneity evaluation. The within-unit homogeneity evaluation model established can overcome the problem in obtaining the multi transformation data in the standard model, and can be widely used in various capacity verification projects.
Keywords：proficiency test; homogeneity evaluation; variance analysis; within-unit; between-unit
ZHANG H L，CHENG L，GAO X M，et al. Case and model analysis of between-unit and within-unit homogeneity evaluation of the proficiency test sample of fipronil sulfone in eggs[J]. Chemical analysis and meterage，2020，29(3)：101-106.