Abstract:

This assessment program was established by Shandong Imported and Exported Inspection and Quarantine Bureau of China (SDCIQ) to evaluate the aflatoxin-testing capacity of a cross-section of Peanut Export Industry. The assessment was performed according to ISO 13528: 2005 and the International Harmonized Protocol for Proficiency Testing. The 102 industries were involved in the study. The analytic samples for this scheme were prepared from naturally contaminated peanut butter. The contents of aflatoxin were analyzed by high performance liquid chromatography and fluorometry. The Ss≤0.3σP test was used to evaluate the homogeneity of the test samples and the sample stability was confirmed with a t-test. The performance of each laboratory was designated by a z-score that was calculated using robust statistics. The robust mean of the participants results in this study was nearly coincident with the median. A modified Horwitz equation was used to analyze the standard deviation. 93 samples were observed as satisfactory, 6 as questionable and 3 as unsatisfactory. Samples reported to be questionable or unsatisfactory were further re-evaluated in a second inter-laboratory comparison.

Key words: peanut, aflatoxins, determination capacity