Gas chromatographic determination of fentanyl and its analogues in human plasma

There is currently no published chromatographic assay for the fentanyl family of analgesics. This study reports the development of a sensitive, precise, and accurate gas chromatographic method for the determination of fentanyl and its analogues in human plasma. Sensitivity attained for fentanyl and sufentanil was 0.1 ng/mL plasma with an average coefficient of variation of 4.5%. Calibration curve correlation coefficients of 0.99 or greater were consistently obtained. Average recovery of drug into the final extract exceeded 80% and was independent of fentanyl concentration. The required degree of specificity was obtained by selective extraction, use of the nitrogen/phosphorous detector, and chromatographic resolution. This method appears suitable for clinical studies of fentanyl and its derivatives in man.