Determination of Diazepam in Human Plasma by Solid-Phase Microextraction and Capillary Gas Chromatography-Mass Spectrometry
A simple, sensitive, and reproducible solid-phase microextraction and capillary gas chromatography-mass spectrometry (SPME-GC-MS) method for determination of diazepam in human plasma is described. The optimum conditions for the SPME procedure were as following: direct extraction mode with a polydimethylsiloxane (PDMS) fiber (100 μm film thickness), 250 μL of sample plasma matrix modified with a solution containing sodium chloride (10% weight by volume) and 4.25 mL of a phosphate buffer solution (0.1mol L−1, pH 6.9), extraction temperature 55°C under a magnetic stirring rate of 2500 rpm for 30 min, followed by the drug thermal desorption (250°C) in a GC injection port for 10 min. The limit of quantification of diazepam in plasma was 10.0 ng mL−1, with a coefficient of variation lower than 14.0% and linearity from 10.0 to 1000.0 ng mL−1, which allows diazepam analyses from sub to therapeutic levels.
KeywordsGas chromatography-mass spectrometry Solid-phase microextraction Diazepam in human plasma
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- File SE, Pellow S (1990) Behavioral pharmacology of minor tranquilizers. In: Balfour DJK (ed) Psychotropic Drugs of Abuse. Pergamon Press, New York, pp.147–172Google Scholar
- Ellenhorn MJ (1997) Benzodiazepines. In: Ellenhorn’s Medical Toxicology, 2nd edn, Willians & Wilkins, Baltimore, pp. 687–695Google Scholar
- Pawliszyn J (1997) In Solid Phase Microextraction: Theory and Practice, Wiley-VCH, New YorkGoogle Scholar
- Pawliszyn J (1999) In Applications of Solid Phase Microextraction, Royal Society of Chemistry, LondonGoogle Scholar
- Theodoridis G, Koster EHM, Jong GJ (2000) J Chromatogr B 745:49–82Google Scholar
- Krogh M, Grefslie H, Rasmussen K (1997) J Chromatogr B 689:357–362Google Scholar
- Queiroz MEC, Lanças FM (2004) LCGC North America 22:970–980Google Scholar