Screening method for benzodiazepines and hypnotics in hair at pg/mg level by liquid chromatography-mass spectrometry/mass spectrometry.
A procedure is presented for the screening of 16 benzodiazepines and hypnotics in human hair by LC-MS/MS (alprazolam, 7-aminoclonazepam, 7-aminoflunitrazepam, bromazepam, clobazam, diazepam, lorazepam, lormetazepam, midazolam, nordiazepam, oxazepam, temazepam, tetrazepam, triazolam, zaleplon and zolpidem). The method involves decontamination of hair with methylene chloride, hair cut into small pieces, incubation of 20 mg in phosphate buffer (pH 8.4) in the presence of 1 ng diazepam-d5 used as internal standard, liquid-liquid extraction with diethyl ether/methylene chloride (10/90) and separation using liquid chromatography-tandem mass spectrometry. The limits of quantification for all benzodiazepines and hypnotics range from 0.5 to 5 pg/mg using a 20-mg hair sample. Linearity is observed from the limit of quantification of each compound to 200 pg/mg (r2 > 0.99). Coefficients of variation measured on six points and at two concentrations (10 and 50 pg/mg) range from 5 to 20% for all drugs but one. Extraction recovery, measured at the two same concentrations range from 32 to 76%. These results were found suitable to screen for 16 benzodiazepines in hair and detect them at very low concentrations, making this method suitable to monitor single dose.
Villain
Marion
M
Laboratoire ChemTox, rue Grüninger, 67400 Illkirch, France. mvillian@labochemtox.com
Concheiro
Marta
M
Cirimele
Vincent
V
Kintz
Pascal
P
D001569:Benzodiazepines / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006197:Hair / Q000737:chemistry*; D006801:Humans; D006993:Hypnotics and Sedatives / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D006993:Hypnotics and Sedatives; D001569:Benzodiazepines