Part No: PPS443Issued year: 2017File size: 2.31mbFile type: pdf
Analysis of drug panels in urine samples can be challenging, and the trend towards larger panels including multiple drug classes compounds the issues faced during method development.
This white paper examines a number of aspects of sample preparation, and their impact on the success of subsequent LC-MS/MS analysis of broad urine panels.
Section 1 examines the applicability of various sample preparation techniques: supported liquid extraction, reverse phase SPE and mixed-mode SPE, to the various classes of drugs extracted. In addition, hydrolysis approaches: enzyme type and protocol used (time, temperature), are compared.
Mixed-mode reverse phase/cation exchange SPE is widely used for extraction of basic drug classes from urine, but the inclusion of drugs and metabolites that exhibit ‘non-typical’ functionality within urine panels can be problematic. Section 2 examines the impact of various parameters (interference wash strength, elution solvent composition) on analyte retention, elution and extract cleanliness with particular focus on zwitterionic (gabapentin, pregabalin) and non-ionic (carisoprodol, meprobamate) drugs.
Part No: P156Issued year: 2017File size: 0.23mbFile type: pdf
Most drugs are excreted in urine as glucuronide conjugates. Hydrolysis using a beta-glucuronidase enzyme to convert the metabolites to their “free” form for analysis increases sensitivity. Red abalone (Kura Biotech), abalone (Campbell Scientific), and recombinant (IMCSzyme) beta-glucuronidase enzymes were evaluated to determine which provided the most complete hydrolysis of glucuronide metabolites without effecting the overall recovery of non-conjugated compounds.
EVOLUTE EXPRESS CX 96-well plates were used to extract hydrolysed urine samples, and the impact of th enzymes was compared.
MSACL 2017, Palm Springs