ABSTRACT
Quality assurance (QA) is an objective assessment of a laboratory’s capability and commitment to produce repeatable, defendable, and accurate data. QA includes regulation of the quality of raw materials, assemblies, products, and
4.1 Introduction 77 4.2 e PDCA Cycle 78 4.3 Calibration Laboratories 79 4.4 Method Validation 79
4.4.1 Selectivity 79 4.4.2 Calibration Model 80 4.4.3 Precision 80 4.4.4 Bias 80 4.4.5 Limit of Detection 81 4.4.6 e Lower Limit of Quantication 81 4.4.7 Statistical Process Control 81 4.4.8 Measurement Uncertainty 82
4.4.8.1 Horwitz Equation 86 4.4.8.2 Reporting of Uncertainty 86 4.4.8.3 Compliance against Limits 87
4.5 Practical Examples (Forensic Toxicology) 87 4.6 Prociency Testing Schemes 89 References 89
components; services related to production; and management, production, and inspection processes. Two key principles characterize QA: “t for purpose” and “right at the rst time.” It is important to realize also that quality is determined by the intended users. However, a considerable part of users of results of quantitative measurements may be unaware of the necessary quality measures behind reported results. is is particularly important in forensic issues, at court and in jurisdiction, where not only forensic medical experts but also analytical laymen rely on reported results, which need to be correct, objective, and reproducible by any other lab working with comparable methods and standards. erefore, internationally accepted standards must anticipate forensic analytical quality needs. To achieve these objectives, international standards should be used. Reliable analytical methods are required for compliance with national and international regulations in all areas of analysis. According to the “harmonized guidelines for singlelaboratory validation of methods of analysis” (IUPAC technical report), a laboratory must take appropriate measures to ensure that it is capable of providing and does provide data of the required quality [1].
