31. LC-MS/MS Analysis of Buprenorphine and its Metabolites in Urine and the Importance of Norbuprenorphine Cross-Reactivity in an Immunoassay Screen
Poster: Tue 2:00-3:00PM
Christine Moore
Immunalysis Corporation
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Buprenorphine (BUP) is metabolized to norbuprenorphine (nor-BUP), followed by glucuronide conjugation. Using urine specimens analyzed by direct injection LC-MS/MS for BUP, nor-BUP and glucuronides, we evaluated two urine buprenorphine immunoassays (Immunalysis (IMM) & Microgenics (MCG)). Of 14 discrepant samples, 13 samples screened positively by IMM and negatively by MCG; one screened negatively by IMM and positively by MCG at the concentrations discussed. The sensitivity, specificity and accuracy of the assays for IMM were 100%, 97%, and 99%; MCG 79%, 97%, and 86%, respectively. The LC-MS/MS confirmation method was simple, sensitive and rapid, and no hydrolysis of urine samples was required.