Significance and UseApplication of Uncertainty—Qualitative and quantitative analyses require different approaches, refer to the references for additional information. Analysts shall understand the limitations of qualitative and quantitative determinations and have tools to estimate a value for measurement uncertainty of relevant, but not necessarily all, numerical results. In this regard, efforts should be made to use the vocabulary, symbols, and formatting expressed in documents published by international standardizing organizations such as ISO and ASTM International. An understanding of uncertainty is fundamental to the interpretation and reporting of results. The term “uncertainty” does not imply doubt; rather, its consideration provides assurance that results and conclusions from methods and analytical schemes are fit for purpose. The concept of uncertainty shall be considered for both qualitative and quantitative results. Laboratory management shall ensure that uncertainty be addressed through the provision of training, procedures and documentation. Laboratory management should consider customer requirements, such as a request for qualitative versus quantitative determinations, which influence the assessment of uncertainty. The benefits of understanding and determining uncertainty in this context include: Enhancing confidence through increased understanding of results, Providing a mechanism to express the reliability of results, Enabling the laboratory management and customer to evaluate the fitness for purpose of results, Facilitating the identification of procedural limitations and providing a basis for improvement, and Complying with accreditation requirements.Scope1.1 This practice provides guidance on the concept of uncertainty and its application to the qualitative and quantitative analysis of seized drugs. In this context, uncertainty encompasses limitations of qualitative methods as well as numerical ranges as applied to quantitative analyses. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
