A simple gas chromatography-mass spectrometry procedure for the simultaneous determination of buprenorphine and norbuprenorphine in human urine.

With the increasing use of buprenorphine in treatment of opiate addiction and pain management, it is important that laboratories be able to assess patient compliance. The presented procedure is simple, efficient, and employs gas chromatography-mass spectrometry (GC-MS) technology available to most laboratories. The specimen is hydrolyzed with beta-glucuronidase prior to liquid-liquid extraction at a basic pH. The evaporated extract is derivatized to form the tertiary-butyl-dimethyl-silyl derivatives of buprenorphine and norbuprenorphine prior to analysis by GC-MS in the electron impact mode. Confirmation of the analytes is based on comparing the ion abundance ratios of the analytes to those of a contemporaneously analyzed standard. The qualitative ion abundance ratios are required to be within 20% of those of the standard for acceptance. Quantification is based on the ion ratios of the analytes to those of their corresponding deuterated analogues. Linearity was obtained for buprenorphine in the range of 1 to 2000 microg/L with a correlation coefficient (R) exceeding 0.999 and for norbuprenorphine from 1 to 1000 microg/L with R exceeding 0.997. Percent recoveries for the buprenorphine and norbuprenorphine were 71% and 75%, respectively. It was found that the recovery of norbuprenorphine could be enhanced to 100% by a simple "salting-out" modification to the procedure.