Poo Susan, Palma Miguel, Muñoz Ociel
Laboratory for Measurement Quality Assurance (LACM), Institute of Food Sciences and Technology, Faculty of Agricultural and Food Sciences, Universidad Austral de Chile, Valdivia 5090000, Chile.
Department of Analytical Chemistry, Center of Agri-Food and Wine Research (IVAGRO), Faculty of Science, University of Cadiz, 11510 Puerto Real, Spain.
Foods. 2024 Aug 26;13(17):2693. doi: 10.3390/foods13172693.
Proficiency testing (PT) allows food laboratories to endorse their competency to provide food safety guarantees to producers and consumers. One of the recommended methods for assigning reference values in PT with a small number of participants consists in considering the results that a laboratory obtains by means of a calibration test based on certified reference material (CRM). The present study delves into the results from eight PT rounds on the determination of fat and crude protein from raw milk, with modifications in the number of samples and the analysis sessions from that required by the ISO 13528:2022. The uncertainty criterion of the assigned value established by the ISO 13528:2022 standard was met by 93% of the participating laboratories, which allowed most participants to be evaluated through z-score. The assigned values were generally compatible with the results obtained by the participants. Thus, it can be concluded that the design for the assignment of the reference value is appropriate for PT with a limited number of participants. It is recommended for future PT to limit the uncertainty of the CRM according to their availability and to update the standard deviation of the proficiency assessment for the Mid-Infrared Spectroscopy method (MIR).
能力验证（PT）使食品实验室能够证明其有能力为生产者和消费者提供食品安全保障。在参与者数量较少的PT中，一种推荐的参考值赋值方法是考虑实验室通过基于有证标准物质（CRM）的校准测试所获得的结果。本研究深入探讨了八轮生乳脂肪和粗蛋白测定能力验证的结果，样本数量和分析环节与ISO 13528:2022的要求有所不同。93%的参与实验室符合ISO 13528:2022标准确定的赋值不确定度标准，这使得大多数参与者能够通过z分数进行评估。赋值通常与参与者获得的结果相符。因此，可以得出结论，参考值赋值设计适用于参与者数量有限的PT。建议未来的PT根据CRM的可用性限制其不确定度，并更新中红外光谱法（MIR）能力评估的标准偏差。
