A gas chromatography-mass spectrometry (GC-MS)-based screening procedure was developed for the detection of diuretics, uricosurics, and/or their metabolites in human urine after extractive methylation. Phase-transfer catalyst remaining in the organic phase was removed by solid-phase extraction on a diol phase. The compounds were separated by GC and identified by MS in the full-scan mode. The po...

A simple gas chromatography-mass spectrometry (GC-MS) procedure has been developed for the main metabolites of organophosphorus nerve agents, alkylmethylphosphonic acids (AMPAs; alkyl = Et, i-Pr, and pinacolyl) in biofluids via extractive pentafluorobenzylation. The derivatization was carried out under liquid-liquid-solid-phase-transfer conditions using a polymer-bound tri-n-butylmethylphosphon...

Twenty patients with cirrhosis and ascites but no renal failure were given piretanide, a new loop diuretic, in order to investigate its efficacy and to relate the diuretic response with the pretreatment plasma aldosterone concentration. Eleven patients responded to piretanide 12 mg/day (equivalent in potency to 80 mg furosemide); there was no response in nine patients. Both groups were similar ...

Aramine (metaraminol bitartrate) has been found in the possession of horse trainers and veterinarians who have been investigated for possible inappropriate drug administration to racing horses. Metaraminol (3-hydroxyphenylisopropanolamine) is a sympathomimetic amine that directly and indirectly affects adrenergic receptors, with alpha effects being predominant. Because it has the potential to a...

We compared oral fluid testing to urine testing in subjects who were administered single doses of marijuana by smoked and oral routes. Oral fluid specimens were collected with the Intercept DOA Oral Specimen Collection Device, screened for THC with the Cannabinoids Intercept MICRO-PLATE Enzyme Immunoassay (EIA) utilizing a 1.0-ng/mL cutoff concentration, and confirmed for THC by gas chromatogra...

The major purpose of human biomonitoring is the mapping and assessment exposure to chemicals. European initiative HBM4EU has prioritized seven substance groups two metals relevant for exposure: Phthalates substitutes (1,2-cyclohexane dicarboxylic acid diisononyl ester, DINCH), bisphenols, per- polyfluoroalkyl substances (PFASs), halogenated organophosphorous flame retardants (HFRs OPFRs), polyc...

Common ethanol detection methods are not applicable to cell culture media and microdialysates due to interference with medium constituents including amino acids and pH indicators. We present a novel GC-MS method for the accurate and precise analysis of ethanol in cell cultures and microdialysates. The method is based on the carbonate-catalyzed extractive pentafluorobenzoylation of ethanol and d...

Gas chromatography/mass spectrometry (GC/MS) with negative ion chemical ionization permits detection of underivatized patulin in apple juice extracts while minimizing co-extractive responses. The technique has been used with a variety of capillary columns in quadrupole, ion trap, and magnetic sector GC/MS instruments to confirm presumptive findings of patulin in apple juice at concentrations ra...