Analysis of urinary benzodiazepines using solid-phase extraction and gas chromatography-mass spectrometry.
A solid-phase extraction and GC-MS confirmation method was developed for certain urinary diazolo- and triazolobenzodiazepines, including the metabolites of lorazepam, clonazepam, alprazolam, and triazolam. The latter two do not form benzophenones, and the others are not readily confirmed by conventional thin-layer chromatography or GC-MS techniques. Samples were hydrolyzed with glucuronidase at 37 degrees C, adjusted to pH 4.5, extracted with Bond Elut Certify columns, dried, and derivatized using BSTFA with 1% TMCS. Sample preparation time averaged 4 hours. A GC-MS selected-ion-monitoring acquisition method targeting retention time, molecular ion abundances, and qualifier ion ratios was used to determine positive results. The recovery of 7-NH2-clonazepam was 95%, and recoveries of alpha-hydroxyalprazolam, alpha-hydroxytriazolam, and lorazepam were greater than 66%. Linearity was demonstrated from 0.1 to 1.0 microgram/mL for each drug. Within-run CVs were less than 11%, and between-run CVs were less than 16%. Using this technique, we have been able to confirm suspected cases of abuse that had not been confirmed by previous techniques.
Black
D A
DA
Department of Veterans Affairs, Medical Center, Seattle, WA 98108.
Clark
G D
GD
Haver
V M
VM
Garbin
J A
JA
Saxon
A J
AJ
D014151:Anti-Anxiety Agents / Q000652:urine; D001569:Benzodiazepines / Q000302:isolation & purification* / Q000652:urine*; D017248:Enzyme Multiplied Immunoassay Technique; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans
D014151:Anti-Anxiety Agents; D001569:Benzodiazepines