A rapid method for detecting barbiturates in serum using EI-SIM

Systematic toxicological analysis procedures for acidic drugs and/or metabolites relevant to clinical and forensic toxicology and/or doping control

This paper reviews systematic toxicological analysis (STA) procedures for acidic drugs and/or metabolites relevant to clinical and forensic toxicology or doping control using gas chromatography, gas chromatography-mass spectrometry, liquid chromatography, thin-layer chromatography and capillary electrophoresis. Papers from 1992 to 1998 have been taken into consideration. Screening procedures in biosamples (whole blood, plasma, serum, urine, vitreous humor, brain, liver or hair) of humans or animals (horse, or rat) are included for the following drug classes: angiotensin-converting enzyme (ACE) inhibitors and angiotensin II (AT-II) blockers, anticoagulants of the 4-hydroxy coumarin type, barbiturates, dihydropyridine calcium channel blockers (calcium antagonists), diuretics, hypoglycemic sulfonylureas and non-steroidal anti-inflammatory drugs (NSAIDs). Methods for confirmation of preliminary results obtained by screening procedures using immunoassay or chromatographic techniques are also included. Furthermore, procedures for the simultaneous detection of several drug classes are reviewed. The toxicological question to be answered and the consequences for the choice of an adequate method, the sample preparation and the chromatography itself are discussed. The basic information about the biosample assayed, work-up, separation column, mobile phase or separation buffer, detection mode and validation data of each procedure is summarized in 16 tables. They are arranged according to the drug class and the analytical method. Examples of typical applications are presented. Finally, STA procedures are reviewed and described allowing simultaneous screening for different (acidic) drug classes.

Automated procedure for determination of barbiturates in serum using the combined system of PrepStation and gas chromatography-mass spectrometry

A system of an automatic sample preparation procedure followed by on-line injection of the sample extract into a gas chromatograph-mass spectrometer (GC-MS) was developed for the simultaneous analysis of seven barbiturates in human serum. A sample clean-up was performed by a solid-phase extraction (SPE) on a C18 disposable cartridge. A SPE cartridge was preconditioned with methanol and 0.1 M phosphate buffer. After loading 1.5 ml of a diluted serum sample into the SPE cartridge, the cartridge was washed with 2.5 ml of methanol-water (1:9, v/v). Barbiturates were eluted with 1.0 ml of chloroform-isopropanol (3:1, v/v) from the cartridge. The eluate (1 microl) was injected into the GC-MS. The calibration curves, using an internal standard method, demonstrated a good linearity throughout the concentration range from 0.1 to 10 microg ml(-1) for all barbiturates extracted. The proposed method was applied to 27 clinical serum samples from three patients who were administrated secobarbital.

Automated preparation and analysis of barbiturates in human urine using the combined system of PrepStation and gas chromatography-mass spectrometry

A system for an automatic sample preparation procedure followed by on-line injection of the sample extract into a gas chromatography-mass spectrometry (GC-MS) system was developed for the simultaneous analysis of seven barbiturates in human urine. Sample clean-up was performed by a solid-phase extraction (SPE) on a C18 disposable cartridge. A SPE cartridge was preconditioned with methanol and 0.1 M phosphate buffer. After loading a 1.5 ml volume of a urine sample into the SPE cartridge, the cartridge was washed with 2.5 ml of methanol-water (1:9, v/v). Barbiturates were eluted with 1.0 ml of chloroform-isopropanol (3:1, v/v) from the cartridge. The eluate (1 microl) was injected into a GC-MS system. The calibration curves, using an internal standard method, demonstrated a good linearity throughout the concentration range from 0.02 to 10 microg/ml for all barbiturates extracted. The proposed method was applied to several clinical cases. The total analysis time for 20 samples was approximately 14 h.