Validation of proficiency test of Rhodamine B in chili oil

In order to find out the capability of Rhodamine B detection in China's food inspection laboratories, meanwhile verify and strengthen the capability of Rhodamine B determination, the National Certification and Accreditation Supervision and Management Committee ( CNCA) organized proficiency test ( PT) of detection of Rhodamine B in Chili oil.Chongqing Entry-Exit Inspection & Quarantine Bureau Technology Center is responsible for specific coordination and implementation.This assessment was performed according to GB/T 27043-2012 ( equivalent to ISO/IEC guideline 17043: 2010) , GB/T 28043-2011, CNASGL02: 2014, CNAS-GL03: 2006, and the international harmonized protocol for proficiency test.The homogeneity of samples was assessed by F test, and the stability was assessed by t-test.The median was used as assigned value to calculate a z-score which was used as a numerical indicator to show participants ' performance in the program. 134 laboratories participated this proficiency test, 124 laboratories were observed as satisfactory, the satisfaction rate was 92.5%, and 8 laboratories showed unsatisfactory result, 1 laboratory quitted due to the equipment's failure.In conclusion, most laboratories taking part in the PT have good competence in analyzing Rhodamine B and most of domestic related laboratories possess a high level of detection.