Abstract
We have developed an automated system for the simultaneous detection of methamphetamine (MA), its precursor drugs that produce MA upon metabolization (dimethylamphetamine, selegiline, benzphetamine, famprofazone, furfenorex, fencamine), and their respective metabolites. The system consists of an automated sample preparation apparatus connected on-line to a liquid chromatograph-tandem mass spectrometer (LC-MS/MS). Urine samples are directly loaded into the system and the following operations are performed sequentially without manual handling: addition of methanol to precipitate urine ingredients, suction filtration with a polytetrafluoroethylene filter, and on-line solid phase extraction with column switching to LC-MS/MS detection. Seventeen analytes were determined within eight minutes on the C18 column. Detection limits upon subjecting a 20 μL specimen were 5 ng/mL-10 ng/mL in selected reaction monitoring mode and 10 ng/mL-100 ng/mL in product ion scan mode. Calibration curves showed satisfactory linearity in the range of 5 ng/mL-1000 (or 2000) ng/mL. Intra- and inter-day precision and accuracy were within 11% and 12%, respectively. The developed system can contribute to the rapid determination of MA in urine along with its origin without complicated operations.
