Anand A. Joshi

An LC-MS method has been developed for simultaneous quantification of buprenorphine and its three metabolites, namely norbuprenorphine, buprenorphine glucuronide, and norbuprenorphine glucuronide Chromatographic separation was achieved on a C18 column with a gradient of acetonitrile and ammonium acetate buffer (25 mM, pH 6.6). The method run time was 7.5 min. Quantification was performed by selected ion monitoring of [M+H]+ ions of norbuprenorphine glucuronide (590), norbuprenorphine (414), buprenorphine glucuronide (644) and buprenorphine (468). Naloxone (328) (328ng/mL) was used as an internal standard. The samples were processed by protein precipitation and extraction recovery was ≥95% with minimal observed matrix effects (