Key aspects of analytical method validation and linearity evaluation

Method validation may be regarded as one of the most well-known areas in analytical chemistry as is reflected in the substantial number of articles submitted and published in peer review journals every year. However, some of the relevant parameters recommended by regulatory bodies are often used interchangeably and incorrectly or are miscalculated, due to few references to evaluate some of the terms as well as wrong application of the mathematical and statistical approaches used in their estimation. These mistakes have led to misinterpretation and ambiguity in the terminology and in some instances to wrong scientific conclusions. In this article, the definitions of various relevant performance indicators such as selectivity, specificity, accuracy, precision, linearity, range, limit of detection, limit of quantitation, ruggedness, and robustness are critically discussed with a view to prevent their erroneous usage and ensure scientific correctness and consistency among publications.