From method validation to result assessment: Established facts and pending questions

This paper aims to present a critical discussion of existing strategies to emphasize possible pitfalls and expected trends that arise from method validation to result assessment. It critically presents some aspects of the three main historical steps, namely terminology, method validation and quality of results. In addition to the formal link between method validation and measurement uncertainty that was recently demonstrated, the abundance of propositions also leads to some problems of consistency. Particular interest is given to the use of tolerance intervals as an appropriate tool to make decisions in method validation, control charts and determination of measurement uncertainty, considering various possibilities regarding adjustments of coverage percentage that can present difficulty for most analytical scientists.