Guthery, Bill; Bassindale, Alan; Pillinger, Colin T. and Morgan, Geraint H.
|DOI (Digital Object Identifier) Link:||http://dx.doi.org/10.1002/rcm.3883|
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A technique using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOFMS) is applied to qualitative and quantitative drug testing. Human serum was spiked with known quantities of benzodiazepines and a street heroin mixture including some of the major metabolites and impurities. The sample components were extracted from the matrix by solid-phase extraction (SPE). Constituents containing polar hydroxyl and/or secondary amine groups were derivatised with N-methyl-N-(tert-butyldimethyl)trifluoroacetamide (MTBSTFA) to improve the chromatographic performance. An orthogonal separation of the matrix constituents was achieved by coupling a DB-5ms (5% phenyl) to a BPX50 (50% phenyl) GC column. The eluant was focused onto the second column by a twin-stage cryo-modulator. Rapid 6 s modulation times were achieved by transfer from a 30 m × 0.25 mm (length × internal diameter) to a 2 m × 0.1 mm column. TOFMS with rapid spectral acquisition (500 spectra/s) was employed in the mass range m/z 40-650. A clean mass spectrum was obtained for each analyte using mass spectral deconvolution software. The sensitivity and repeatability of the method were evaluated by the preparation of calibration standards for two benzodiazepines, flunitrazepam and its major metabolite 7-aminoflunitrazepam (7-amino-FN), in the concentration range 5-1000 ng/mL. The limits of detection (LODs) and limits of quantitation (LOQs), calculated by repeat injections (×10) of the lowest standard, were 1.6 and 5.4 ng/mL (flunitrazepam); 2.5 and 8.5 ng/mL (7-amino-FN), respectively. There is scope to extend this protocol to screen a large number of drugs and metabolites stored in a library database.
|Item Type:||Journal Article|
|Copyright Holders:||2009 John Wiley & Sons, Ltd.|
|Academic Unit/Department:||Science > Physical Sciences
Other Departments > Vice-Chancellor's Office
|Interdisciplinary Research Centre:||Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)|
|Depositing User:||William Guthery|
|Date Deposited:||24 Mar 2009 10:14|
|Last Modified:||24 Jul 2014 09:22|
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