Determination of the elemental composition of an air filter loaded with urban dust (PTXRFIAEA14) by means of the XRF technique

Abstract

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.