Direct Analysis of Urinary Opioids and Metabolites by Mixed-Mode Μelution SPE Combined with UPLC/MS/MS for Clinical Research by Jonathan P
21 Direct Analysis of Urinary Opioids and Metabolites by Mixed-mode µElution SPE Combined with UPLC/MS/MS for Clinical Research by Jonathan P. Danaceau, Erin E. Chambers, and Kenneth J. Fountain, Waters Corporation, Milford, MA The analysis of natural and synthetic opioid drugs continues to be an important aspect of clinical research. In the past, analyses were typically conducted by GC/MS after first subjecting the samples to acid or enzymatic hydrolysis to transform the glucuronide metabolites into the parent form [1]. With the advent of modern LC/MS/MS techniques, however, glucuronide metabolites can now be analysed directly [2-5]. Direct analyses of glucuronide metabolites can eliminate the risk of inaccurate quantification due to incomplete hydrolysis, as enzymatic efficiency can vary greatly depending upon the enzyme used and the drug substrate analysed [6]. The sample preparation approach is also an TX). Complementary, deuterated internal Table 1: UPLC solvent gradient important consideration. Urine samples, standards were used for all compounds with unlike some other matrices, can be analysed the exception of hydromorphone-3- Time (min.) Flow Rate %A %B by ‘dilute and shoot’ methods in which glucuronide, codeine-6-glucuronide, samples are diluted with an internal standard norbuprenorphine-glucuronide, norfentanyl, 0 0.4 98.0 2.0 mix and directly injected onto a LC/MS/MS and buprenorphine-glucuronide. For these 6 0.4 47.2 52.8 system [2, 4]. Disadvantages to this type of compounds, a deuterated IS with the most technique, however, include the fact that similar recovery and matrix effect was chosen 6.5 0.4 98.0 2.0 urine contains many matrix components that as a surrogate.
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