27. März 2013

New AppNote: Barbiturates and COOH-THC in Urine using DPX-LC/MS/MS

Determination of Barbiturates and COOH-THC in Urine using dispersive SPE (Automated Disposable Pipette Extraction; DPX) and LC-MS/MS


This work demonstrates the use of disposable pipette extraction (DPX) as a fast and automated sample preparation technique for the determination of Barbiturates and 11-Nor-9-carboxy-Δ9-THC in urine. Using a GERSTEL MultiPurpose Sampler (MPS) with DPX option coupled to an Agilent 6460 LC-MS/MS instrument, 8 barbiturates and COOH-THC were extracted and their concentrations determined. The resulting average cycle time of 7 min/sample, including just-in-time sample preparation, enabled high throughput screening.
Validation results show that the automated DPX-LC/MS/MS screening method provides adequate sensitivity for all analytes and corresponding internal standards that were monitored. Lower limits of quantitation (LLOQ) were found to be 100 ng/mL for the barbiturates and 10 ng/mL for COOH-THC and % CVs were below 10 % in most cases.


Determination of Barbiturates and 11-Nor-9-carboxy-Δ9-THC in Urine using Automated Disposable Pipette Extraction (DPX) and LC/MS/MS