CERTIFICATION OF MORPHINE-3-BETA-D-GLUCORONIDE IN A HUMAN URINE STANDARD REFERENCE MATERIAL

The U.S. National Institute of Standards and Technology (NIST) has dev eloped and certified a standard reference material, SRM 2382, for use in testing for bias in the determination of morphine present as a gluc uronide in human urine. This SRM consists of three levels of morphine- 3-beta-D-glucuronide (M-3-G) in lyophilized urine. Two independent hyd rolysis procedures, enzymatic and acidic, for quantitative release of morphine were investigated. The results of hydrolysis efficiency from these two procedures agreed well. These two hydrolysis procedures alon g with two analytical methods developed previously for measurement of free morphine [1] were used to certify M-3-G in SRM 2382. Enzymatic hy drolysis was used with the GC/MS method and acidic hydrolysis was used with LC/MS. The results from these two pairs of methods were in good agreement, and were statistically combined to yield certified values o f 209+/-20, 437+/-21, and 853+/-39 ng/mL for morphine, as the free bas e. Round-robin studies on this material among ten military laboratorie s demonstrated the suitability of the SRM for its intended purpose.