Improving performance evaluation via the provision of proficiency testing programmes in Asia–Pacific with metrologically traceable reference values for inorganic elements

This paper reviews some proficiency testing (PT) programmes operated under the auspices of Asia Pacific Metrology Programme and Asia Pacific Laboratory Accreditation Cooperation Joint Proficiency Testing Working Group. The assigned values of these joint PTs are traceable to the SI. Provision of PTs based on reference values (PTRVs) with metrological traceability enables meaningful performance evaluation and assessment of metrological comparability of the participants’ results. Special focus will be given to those joint PTs related to analysis of inorganic elements in various sample matrices organized or co-organized by Government Laboratory of Hong Kong, China. Comparison based on different evaluation criteria (i.e. consensus value vs reference value) is carried out. Comprehensive evaluation and review of some performance indicators revealed several crucial findings such as the performance of different analytical conditions, recent analytical trends and areas of improvements. The organization of a series of these joint PTs could be regarded as a strong support of the concept that PTRV with metrological traceable reference values is an effective way to promote the concept of metrological traceability to the field laboratories and provide a meaningful performance evaluation tool for assessment of PT performance.