Enzymatic hydrolysis of glucuronides is common practice in many of the urine drug testing laboratories utilizing LC-MS/MS. Limitations on directly monitoring glucuronides on tandem mass spectrometry are higher cost of glucuronide standards or lack of certified reference materials of the glucuronidated drug.
However, a major historical challenge for enzymatic hydrolysis has been in opiates. In particular codeine-6-β-D-glucuronide is challenging and generally has poor yield even with incubation time over 2 hours. Although the cutoff concentration of codeine in urine is 2,000 ng/mL according to the guideline from the US Substance Abuse and Mental Health Services Administration (SAMHSA), the various combinations of drugs and their glucuronidated metabolites detected in actual patient urine samples could be as high as 100,000 ng/mL. This study examines the genetically modified β-glucuronidase, IMCSzyme®, and its ability to achieve over 80% recovery of glucuronides in as little as 15 minutes for over 30,000 ng/mL of various glucuronidated opiates in urine.