Proficiency testing
External validation of analytical methods

Table 1 indicates that proficiency testing is another type of collaborative study. In terms of vocabulary, the expressions laboratory intercomparison, or ILC, and proficiency testing, or PT, often come across.

For a long time, PTs were simply collaborative tools, used on a voluntary basis by scientists to develop a common method. With the introduction of ISO/IEC 17025 accreditation, they acquired a rather different role. For instance, as specified in a Cofrac document: “Interlaboratory comparisons are used to assess...