\r\n\tSANTE\/SANCO [ref 4] specifies briefly that an analyte stability in prepared sample extracts has to be evaluated. EU regulation 2021\/808 [ref 5] outlines the stability requirements for the analyte in the solution and in matrix after short-, medium-, and long-term storage.\r\n<\/p>\r\n\r\n
\r\n\tEspecially in the bioanalytical field, the possible analyte decomposition is of very high importance for the quality of the results and therefore deserves special attention. For this reason, the EMA [ref 7], FDA [ref 8] and AOAC [ref 9] validation guidelines specifically address an analyte stability as a separate validation parameter.\r\n<\/p>\r\n\r\n
\r\n\tThe FDA guide [ref 8] distinguishes the following types of stability:\r\n<\/p>\r\n\r\n
\r\n\tThis guideline distinguishes between an analyte stability in the calibration and stock solutions and stability in the sample matrix and stresses the influence of storage conditions, matrix and container system on the stability, in addition to\u00a0the intrinsic properties of the analyte itself. For example, the analyte stability evaluation in whole blood could be valuable in case an analyte is unstable in whole blood or adsorbs to cellular components during the collection procedure.\r\n<\/p>\r\n\r\n
\r\n\tAccording to the EMA [ref 7] guide, a stability of the analyte is evaluated using both low- and high-level QC samples. The investigation of \u00a0stability should cover:\r\n<\/p>\r\n\r\n
\r\n\t\u00a0\r\n<\/p>\r\n\r\n