Determination of buprenorphine, norbuprenorphine, naloxone, and their glucuronides in urine by liquid chromatography–tandem mass spectrometry

Abstract

A liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of buprenorphine (BUP), norbuprenorphine (NBUP), naloxone (NAL), and their glucuronide conjugates BUP-G, NBUP-G, and NAL-G in urine samples was developed. The method, omitting a hydrolysis step, involved non-polar solid-phase extraction, liquid chromatography on a C18 column, electrospray positive ionization, and mass analysis by multiple reaction monitoring. Quantification was based on the corresponding deuterium-labelled internal standards for each of the six analytes. The limit of quantification was 0.

Investigation of buprenorphine‐related deaths using urinary metabolite concentrations

“…In our previous methodological study, we found the following median (maximum) concen- (2310 μg/L). 25 The median NBUPG/BUPG and NBUPtot/BUPtot concentration ratios were 1.8 and 2.5, respectively. These results are consistent with those of the relatively few other published studies on free and total drug concentrations in opioid-dependent patients in OAT.…”

“…The LC-MS/MS method has been previously described. 25 The method involved nonpolar solid-phase extraction, separation on a C18 column, electrospray positive ionization, and mass analysis by triple quadrupole MS/MS, using multiple reaction monitoring. Quantification was based on the corresponding deuterium-labelled internal standards for each of the six analytes.…”

“…For the purpose of this study, we searched the PM toxicology database for individuals deceased in 2020 with a buprenorphine or norbuprenorphine finding in urine obtained by a previously described analytical method 26 . Subsequently, we reanalysed these urine samples using the recently published method for unconjugated BUP, NBUP, and NAL and their glucuronide conjugates BUPG, NBUPG, and NALG 25 . The total concentrations, BUPtot, NBUPtot, and NALtot, were calculated by arithmetic summation of BUP + BUPG, NBUP + NBUPG, and NAL + NALG concentrations, respectively.…”

“…26 Subsequently, we reanalysed these urine samples using the recently published method for unconjugated BUP, NBUP, and NAL and their glucuronide conjugates BUPG, NBUPG, and NALG. 25 The total concentrations, BUPtot, NBUPtot, and NALtot, were calculated by arithmetic summation of BUP + BUPG, NBUP +-NBUPG, and NAL + NALG concentrations, respectively. In addition to the laboratory data, we utilized the forensic pathologist's referral, a brief description of the circumstances of death by the police, the main autopsy findings, and information extracted from the death certificate (time of death, age, gender, cause of death, manner of death) at our disposal.…”

“…Recently, we described the simultaneous quantification of the six relevant analytes, unconjugated buprenorphine (BUP), norbuprenorphine (NBUP), and naloxone (NAL) and the respective conjugated metabolites buprenorphine glucuronide (BUPG), norbuprenorphine glucuronide (NBUPG), and naloxone glucuronide (NALG) in OAT patient urine samples using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. 25 In the present study, our objective is to find diagnostic differences in the urinary concentrations of these analytes between buprenorphine poisonings and other causes of death, applying the recent LC-MS/MS method. Another aim is to differentiate between the parenteral use of the buprenorphinenaloxone combination product and the smuggled monobuprenorphine based on naloxone-related findings in urine.…”