1H NMR analysis of GHB and GBL: Further findings on the interconversion and a preliminary report on the analysis of GHB in serum and urine
Date of Original Version
A 1H nuclear magnetic resonance (1H NMR) method for the determination of gamma-hydroxybutyric acid (GHB) and gamma- hydroxybutyrolactone (GBL) in human serum and urine using spiked samples has been developed. The method gives linear responses (correlation coefficients of 0.99 or greater) over the concentration range 0.01 mg/mL to 4.0 mg/mL in urine and 0.3 mg/mL to 2.0 mg/mL in serum. No sample pretreatment is required. Studies of the chemical interconversion of GBL and GHB showed hydrolysis of GBL to be rapid at pH 11.54, slower and less complete (30% hydrolysis) at pH 2.54 and slowest at pH 7.0, reaching 30% hydrolysis in about 40 days. No esterification of GHB was observed at any pH.
Journal of Forensic Sciences
Del Signore, Anthony G., Michael McGregor, and Bongsup P. Cho. "1H NMR analysis of GHB and GBL: Further findings on the interconversion and a preliminary report on the analysis of GHB in serum and urine." Journal of Forensic Sciences 50, 1 (2005): 81-86. doi:10.1520/jfs2004179.