The detection of various opiates and benzodiazepines by comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry.
A technique using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC x 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 x 0.25 mm (length x internal diameter) to a 2 m x 0.1 mm column. TOFMS with rapid spectral acquisition (< or =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 (x10) 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.
Guthery
Bill
B
Planetary and Space Sciences Research Institute, The Open University, Milton Keynes, UK. w.guthery@open.ac.uk
Bassindale
Alan
A
Pillinger
Colin T
CT
Morgan
Geraint H
GH
D000081:Acetamides; D001569:Benzodiazepines / Q000097:blood* / Q000378:metabolism; D002849:Chromatography, Gas / Q000379:methods*; D005445:Flunitrazepam / Q000031:analogs & derivatives / Q000032:analysis; D005463:Fluoroacetates; D003932:Heroin / Q000097:blood / Q000378:metabolism; D006801:Humans; D016014:Linear Models; D008956:Models, Chemical; D053610:Opiate Alkaloids / Q000097:blood* / Q000378:metabolism; D017646:Organosilicon Compounds / Q000737:chemistry; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D052616:Solid Phase Extraction; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D015813:Substance Abuse Detection / Q000379:methods; D014269:Trifluoroacetic Acid / Q000737:chemistry; D014584:User-Computer Interface
D000081:Acetamides; D005463:Fluoroacetates; D053610:Opiate Alkaloids; D017646:Organosilicon Compounds; D001569:Benzodiazepines; D005445:Flunitrazepam; D003932:Heroin; C059151:N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide; C036343:7-aminoflunitrazepam; D014269:Trifluoroacetic Acid