A laboratory must introduce and apply an appropriate program relating to the process of quality assurance and quality control (QA/QC) to produce reliable measurements. This is best done by ensuring that the method is validated for the intended purpose of analysis. The method must be well documented, the personnel well trained, and the control mechanism must be presented to ensure that the procedure is under statistical control. This paper discusses the participation of the Fundamental and Applied Physics Laboratory in the PTXRFIAEA14 proficiency test organized by the International Atomic Energy Agency laboratories and the use of established analytical procedures for the determination of chemical element concentrations in an urban dust loaded on air filters by the XRF technique. The submitted results were processed, grouped with respect to analytes/laboratories, and compared to the assigned and consensus values of the analyte. The z-score, u-score, relative bias, and Standard Deviation Index (SDI) values were calculated according to the QA/QC procedure. The bowtie approach to present the overall concept, the failure-effect tree to identify the causes of bias and their consequences on the measurement results, and the criticality matrix to assess the performance of a laboratory were introduced for the first time.

中文翻译：

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用 XRF 技术测定装有城市灰尘的空气过滤器 (PTXRFIAEA14) 的元素组成

实验室必须引入并应用与质量保证和质量控制 (QA/QC) 过程相关的适当程序，以产生可靠的测量结果。最好通过确保该方法针对预期的分析目的进行验证来实现。该方法必须有据可查，人员必须经过良好培训，并且必须提出控制机制以确保程序处于统计控制之下。本文讨论了基础和应用物理实验室参与由国际原子能机构实验室组织的 PTXRFIAEA14 能力测试，以及使用已建立的分析程序来确定 XRF 加载在空气过滤器上的城市灰尘中的化学元素浓度技术。提交的结果被处理，根据分析物/实验室分组，并与分析物的指定值和一致值进行比较。根据 QA/QC 程序计算 z 分数、u 分数、相对偏差和标准偏差指数 (SDI) 值。首次引入了用于呈现总体概念的领结方法、用于识别偏差原因及其对测量结果的后果的失效-影响树，以及用于评估实验室性能的临界矩阵。