Monitoring of the interconversion of gamma-butyrolactone (GBL) to gamma hydroxybutyric acid (GHB) by Raman spectroscopy

Munshi, T., Brewster, V. L., Edwards, H. G. M. , Hargreaves, M. D., Jilani, S. K. and Scowen, I. J. (2013) Monitoring of the interconversion of gamma-butyrolactone (GBL) to gamma hydroxybutyric acid (GHB) by Raman spectroscopy. Drug Testing and Analysis, 5 (8). pp. 678-682. ISSN 1942-7603

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Gamma-hydroxybutyric acid (GHB) is a drug-of-abuse that has recently become associated with drug-facilitated sexual assault, known as date rape. For this reason the drug is commonly found 'spiked' in alcoholic beverages. When GHB is in solution it may undergo conversion into the corresponding lactone, Gamma-butyrolactone (GBL). Studies have been carried out to determine the detection limits of GHB and GBL in various solutions by Raman spectroscopy and to monitor the interconversion of GHB and GBL in solution with different pH conditions and temperature. In this study, a portable Raman spectrometer was used to study the interconversion of GHB and GBL in water and ethanol solutions as a function of pH, time, and temperature. The aim of this was to determine the optimum pH range for conversion in order to relate this to the pH ranges that the drug is likely to be subjected to, first in spiked beverages and secondly after ingestion in the digestive system. The aim was also to identify a timescale for this conversion in relation to possible scenarios, for example if GHB takes a number of hours to convert to GBL, it is likely for the beverage to be ingested before esterification can take place. GHB and GBL were then spiked into a selection of beverages of known pH in order to study the stability of GHB and GBL in real systems. © 2012 John Wiley & Sons, Ltd.

Additional Information:Article first published online: 6 DEC 2012
Keywords:4 hydroxybutyric acid, alcohol, gamma butyrolactone, water, article, drug monitoring, drug stability, esterification, high temperature, limit of detection, low temperature, pH, priority journal, Raman spectrometry
Subjects:F Physical Sciences > F100 Chemistry
Divisions:College of Science > School of Chemistry
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ID Code:13012
Deposited On:19 Mar 2014 19:13

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