Preanalytical challenges in clinical and forensic toxicology: Implications for result interpretation and patient safety

Gören İ. E.

10TH INTERNATIONAL CONGRESS ON CURRENT APPROACHES IN MEDICINE, NURSING, MIDWIFERY, AND HEALTH SCIENCES, İzmir, Türkiye, 16 - 18 Eylül 2026, ss.150-160, (Tam Metin Bildiri)

Özet

The reliability of toxicological analysis depends not only on analytical performance but also on the conditions under which biological specimens are selected, collected, transported, stored, and processed before analysis. This preanalytical phase is particularly important in clinical and forensic toxicology, where analytical findings may influence therapeutic decisions, assessment of exposure, determination of impairment, or medico-legal conclusions. This review aimed to examine the major preanalytical challenges affecting toxicological testing and to evaluate their implications for result interpretation and patient safety. A review of peer-reviewed literature and relevant professional guidance documents was conducted, with emphasis on biological specimen selection, collection procedures, containers and preservatives, transportation, storage conditions, analyte stability, contamination, and documentation. The reviewed evidence identified specimen type and collection site, inappropriate or insufficient sample volume, unsuitable containers or preservatives, delayed processing, inadequate temperature control, repeated freeze-thaw cycles, and incomplete documentation as recurrent sources of preanalytical variability. Their effects are analyte- and matrix-dependent and may result in degradation, formation or redistribution of analytes, contamination, altered measured concentrations, or loss of information required for reliable interpretation. In forensic settings, these factors may additionally compromise the evidential value of toxicological findings, whereas in clinical settings they may contribute to inappropriate interpretation and subsequent patient management. Standardized specimen collection protocols, analyte-specific storage and preservation strategies, adequate documentation of sampling conditions, and effective communication between laboratories and healthcare or forensic professionals are therefore essential. Greater recognition and control of preanalytical variables can reduce preventable uncertainty and improve the reliability, comparability, and clinical or medico-legal value of toxicological results.