CEDIA method in amphetamine and cannabinoid analysis – potential applications in forensic toxicology blood tests

Abstract

Introduction: Immunoassays are the 1st stage of clinical and forensic toxicology examinations.The aim of the research was to evaluate the suitability of CEDIA (cloned enzyme donor immmunoassay) for the detection of selected drugs such as amphetamine, tetrahydrocannabinol (THC) metabolite: tetrahydrocanabinolic acid (11-nor-9-carboxy-Δ9-tetrahydrocannabinol – THC-COOH).Materials and methods: Blood samples were examined for the presence of the selected psychoactive drugs, similar in effect to alcohol. Whole blood samples were centrifuged, and the obtained plasma was analysed using CEDIA and LC-MS/MS.Results: We observed a strong correlation between amphetamine levels measured with CEDIA and the reference technique (LC-MS/MS), and a lack correlation for THC-COOH levels. Cloned enzyme donor immmunoassay did not provide false positive results – positive samples in CEDIA were also positive in LC-MS/MS, which demonstrated the high specificity of CEDIA.Conclusions: Considering the high specificity in tests for amphetamine and cannabinoids, CEDIA can be used as a qualitative method in forensic and clinical analysis. This study demonstrates a linearity only for amphetamine detection, which may suggest the need for further verification of the results of other assays offered by the manufacturer. Only serum/plasma can be analysed with CEDIA, which makes this technique unsuitable for highly degraded samples.Keywords: immunoenzyme techniques; screening methods; CEDIA; LC-MS/MS; psychoactive drugs.