Simultaneous determination of nalbuphine and opiates in human hair by gas chromatography-mass spectrometry

Abstract

The method for simultaneous determination of nalbuphine and opiates (codeine, morphine, and 6-monoocetylmorpkine) in human hair was developed in the selected-ion monitoring (SIM) mode of a gas chromatography-mass spectrometer (GC-MS). Thirty-milligram hair samples were incubated in 0.01 M HCl overnight at 50 degreesC. We extracted the drugs from resulting hydrolyzed solutions with a mixture of chloroform-isopropanol-n-keptone (50:17:33, v/v/v) at pH 9.2. The residues were then evaporated, derivatized, and injected into the GC-MS with the internal standards. The limits of quantification for codeine, morphine, 6-monoacet morphine, and nalbuphine were 0.26, 0.21, 0.24, and 0.18 ng mg(-1), respectively. Drug recoveries fell in the range 72.4-86.5%. The responses were linear, with correlation coefficients (r > 0.9958) for the drugs studied. This study also demonstrated that hair dyeing or bleaching diminished the concentration level of nallouphine, in vitro.