Detection of 4-hydroxycoumarin anticoagulants and their metabolites in urine as part of a systematic toxicological analysis procedure for acidic drugs and poisons by gas chromatography–mass spectrometry after extractive methylation

Abstract We describe a method for efficiently extracting basic, neutral, and weakly acidic drugs from plasma for toxicological analysis by gas chromatography-mass spectrometry (GC/MS). The 2-mL plasma sample is diluted with an equal volume of saturated NaCl containing triethylamine, 10 mmol/L, and then extracted twice with 4 mL of an equivolume solution of dichloromethane/acetone. The organic (top) phases are combined, then mixed with 1 mL of water, 200 mg of NaHCO3, and 100 microliters of acetic anhydride. This mixture is then heated at 75 degrees C until the solvents have boiled off and aqueous acetylation is complete (less than 30 min). After addition of 1 mL of water and 2 g of NaCl, the sample is extracted twice with 2 mL of dichloromethane/acetone (2/1 by vol). The combined extracts are dried and then subjected to thin-layer chromatography on a blank Toxi-Lab Toxi-A chromatogram with 1-chlorobutane as the developing solvent (about 6 min). After the lipids have migrated with the mobile phase, the drugs are eluted from the origin with acetone/triethylamine (29/1 by vol), evaporated, and reconstituted in injection solvent. With this procedure drugs are recovered relatively quickly (less than 2 h) and the GC/MS total ion chromatograms are very clean. Studies with 13 basic, neutral, and weakly acidic drugs showed that all except theophylline were extracted with recoveries of at least 75%.

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Systematic toxicological analysis using liquid chromatography-mass spectrometry: techniques and inter-instrument reproducibility of mass spectra/Systematisch-toxikologische Analyse mittels Hochleistungsflüssigchromatographie-Massenspektrometrie: Techniken und Reproduzierbarkeit von Massenspektren zwischen Instrumenten

LaboratoriumsMedizin ◽

10.1515/labmed-2011-0014 ◽

2012 ◽

Vol 36 (2) ◽

Cited By ~ 1

Author(s):

Frank T. Peters ◽

Dirk K. Wissenbach

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Mass Spectra ◽

Forensic Toxicology ◽

Gas Chromatography Mass Spectrometry ◽

Reference Library ◽

Toxicological Analysis ◽

Systematic Toxicological Analysis ◽

Chromatography Mass Spectrometry ◽

Universal Reference

AbstractThe so-called systematic toxicological analysis (STA) aiming at simultaneous analysis of as many toxicologically relevant compounds in biosamples as possible is an important part of routine analysis in clinical and forensic toxicology. Gas chromatography-mass spectrometry and liquid chromatography with diode array detection have been the most widely used techniques for this purpose. However, in recent years STA methods based on liquid chromatography coupled to mass spectrometry (LC-MS) or tandem mass spectrometry (LC-MS/MS) have become increasingly important, although their widespread use is still hampered by the lack of a universal reference library of mass spectra that can be used on all major instrument platforms. In this review, LC-MS(/MS) methods for STA in urine and/or blood published in the past 6 years will be compared and discussed with regard to sample preparation, separation, instrument types used for mass spectrometric detection, and method validation. In addition, different approaches to achieving the goal of a universal reference library will be summarized.

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