Determination of meperidine, tramadol and oxycodone in human oral fluid using solid phase extraction and gas chromatography–mass spectrometry

Analytical procedures for the determination of meperidine, tramadol and oxycodone in oral fluid have been developed and validated using gas chromatography–mass spectrometry (GC/MS) following initial screening with enzyme linked immunosorbent assay (ELISA). The oral fluid samples were collected using the Quantisal™ device, and any drugs present were quantified using mixed mode solid-phase extraction and electron impact GC/MS. For confirmation, three ions were monitored and two ion ratios determined, which were within 20% of those of the known calibration standards. The limits of quantitation were 10 ng/mL; the intra-day precision of the assays (n = 5) was 2.33%, 1.00% and 7.61%; inter-day precision 2.48%, 2.44% and 5.8% (n = 10) for meperidine, tramadol and oxycodone, respectively. The percentage recovery of the drugs from the collection pads was 86.7%, 87.7% and 96.6%, respectively (n = 6). The methods were applied to specimens obtained during research studies in the USA.