Abstract
Mixed-mode solid-phase extraction methods were compared for drug screening, prior to gas chromatography/mass spectrometry (GC/MS) and/or liquid chromatography/mass spectrometry (LC/MS). The extractions with Oasis® MCX, ISOLUTE® HCX and Bond Elut Certify® were evaluated by recoveries of acetaminophen, bromvalerylurea, phenobarbital, pentobarbital, amobarbital, chlorpromazine, levomepromazine, promethazine, flunitrazepam, and nitrazepam from human serum. The recoveries were low (0% to 42%) with Bond Elut Certify® for drugs examined except for bromvalerylurea (117%). The recoveries with ISOLUTE® HCX were high (80% to 110%) for all drugs except acetaminophen (33%). The recoveries with Oasis® MCX ranged from 54% to 116% for all drugs including acetaminophen (111%) by using acetonitrile as eluting solvents. The detection limit of each compound ranged 5 to 50 ng on column under scan modes of GC/MS or LC/MS and 0.05 to 0.5 ng on column under SIM modes.
This study suggests that Oasis® MCX is a suitable disposable cartridge in routine drug screening in forensic toxicological analysis.
