The aim of the study was to develop a LC-MS-MS method able to detect and quantify a number of frequently prescribed antipsychotic and antidepressant drugs for toxicological purposes. Separation of compounds was performed on a C-18 RP column by Ultra High-Pressure Chromatography over a 11 min run. A modified single step QuEChERS protocol consisted essentially by the addition of acetonitrile, potassium carbonate and magnesium sulfate in 100 μL of sample, vortexing, centrifugation and evaporation has been selected. The method achieves satisfactory recoveries for 15 psychotropic drugs with a mean R% of 85% and provides efficient purification of the sample from endogenous interferences, simplicity and short sample handling times. The method was validated and provided satisfactory accuracy with recoveries ranging from 85 to 113% and precision with CV ranging from 1.2 to 13.2%. LODs were determined to be from 0.0003 to 0.017 μg/mL while LOQs were from 0.001 to 0.05 μg/mL for the 15 drugs. Matrix effect was below 20% and the analytes were stable in the matrix for 3 weeks. The method proved to be suitable for both analysis of clinical samples for Therapeutic Drug Monitoring and antemortem or postmortem whole blood samples of forensic cases. A number of samples with clinical and forensic interest were successfully analyzed demonstrating the effectiveness of QuEChERS in this field.

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Abstract:In the present study liquid-liquid extraction (LLE) of amphetamine from biological samples was systematically optimised. The recovery of amphetamine extraction was studied using a variety of 5 solvents (chloroform, 1-chlorobutan, dichloromethane, diethylether, ethyl acetate) as well as a system of solvents (chloroform: ethyl acetate: ethanol, 3:1:1 v/v). Furthermore the influence of the volume of the extracting solvent and the pH on the recovery of amphetamine was examined. The optimum conditions of LLE procedure were applied for the extraction of amphetamine from biological samples such as urine, blood and also from less commonly used biological specimens such as liver, bile, brain, vitreous humour, pericardial fluid, cerebrospinal fluid, bone marrow and bone. The determination of amphetamine was accomplished by gas chromatography equipped with a flame ionization detector (FID), after derivatization with heptafluorobutyric anhydride (HFBA).

Niflumic acid is a nonsteroidal, anti-inflammatory drug widely prescribed in Greece. We recently noticed that this drug cross-reacts for cannabinoids in a kinetic interaction of microparticles in a solution (KIMS) immunoassay method but does not in an enzyme multiplied immunoassay technique (EMIT) immunoassay method. The objective of the study was to develop and validate a high-performance liquid chromatographic method in order to evaluate niflumic acid cross-reactivity in two commercial immunoassays for cannabinoids in urine, both in niflumic acid standards as well as in urine specimens obtained from subjects receiving niflumic acid. Urine niflumic acid standards were prepared in drug-free urine at 13 concentrations ranging from 1.25 to 1000 microg/mL. The standards gave presumptive positive cannabinoids results when analyzed by the KIMS immunoassay method when the concentration was above 2.5 microg/mL. None of the prepared standards gave a false-positive cannabinoid result when analyzed by the EMIT immunoassay method. By applying a 50 ng/mL cutoff for cannabinoids in these assays, all 55 urine specimens collected from the 5 subjects who participated gave negative results by the EMIT and false-positive results by the KIMS immunoassay method. It is concluded that KIMS is more prone to cross-reactions by niflumic acid compared to EMIT. Therefore, all positive screening tests for cannabinoids obtained by KIMS should be confirmed by another technique.

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