Sample Traceability in Toxicology

Sampling is an instrument that allows having a portion that represents a whole, and, quantitatively, it allows to measure a specific analyte or several analytes, for diagnostic, clinical, and forensic exposure or control over time, based in a pre-established and validated study plan. In clinical and forensic samples from one individual, the toxicokinetic and toxicodynamic factors should be considered in order to choose the most adequate matrix to study. In case of deceased individuals, additional matrices should be considered to the usual matrix. Sampling should be representative as for quality and quantity and should be associated to a chain of custody. Transport, storage, and analysis of samples are related to the type of matrix and the analyte to identify/measure. All samples should be traceable in any stage of the analysis and should receive an internal codification on entry. Also, the analytical method should be validated and associated to a traceable quality management system. Lastly, biosafety should consider the international recommendations for classification of mixtures and the residue management, in order to ensure the operativity of the technical working group.