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.