(K)ILO project: proficiency tests for students

Abstract

The (K)ILO school project (Quality in Laboratory Education) is a yearly collection of proficiency tests (PT). Students in the (K)ILO project are required to devise their own measurement plan, covering all aspects of sample preparation and analysis and to report and defend their results before an external jury. This paper reports on the 2023 year’s project where mass fractions (g/kg levels) of copper, iron, magnesium and zinc in a feed premix material (BPT-MIN2022-KILO) were determined by the participants. The students’ PT results clearly show a big difference in overall performance, z scores and number of outliers, when the statistical approach depends on the assigned value (AV), derived from formulation or from consensus) and the standard deviation for proficiency testing (σ_pt) fixed or derived from algorithm A. As an example, the overall performance of the four parameters with the consensus method that was assessed as satisfactory is between the range 72 to 100 % and that satisfactory performance was only 27 to 36 % when benchmarked against predetermined AVs indicating that there are underlying analytical measurement issues (most probable arising from the trace metal from sample extraction step and no information about the minimal sample intake). Of course, the students’ results and their deviations and dissemination must be seen in perspective compared to commercial laboratories with all their experience. The (K)ILO project is a valuable instrument of knowledge for future laboratory staff for understanding laboratory activities and their impact on PT results. Perhaps an international (K)ILO project could create more awareness among (future) laboratory staff of the importance of PT and quality.