Urinary γ-hydroxybutyrate concentrations in 1126 female subjects

TY - JOUR

T1 - Urinary γ-hydroxybutyrate concentrations in 1126 female subjects

AU - Brailsford, Alan

AU - Cowan, David A

AU - Kicman, Andrew T

PY - 2010/11

Y1 - 2010/11

N2 - γ-Hydroxybutyrate (GHB) and its metabolic precursor γ-butyrolactone (GBL) are often implicated in cases of drug-facilitated sexual assault (DFSA), although definitive confirmation of GHB/GBL ingestion is complicated by GHB's endogenous nature and rapid elimination following ingestion. Multiple studies have attempted to establish a discriminant limit (generally 10 mg/L) above which urinary GHB concentrations can be considered consistent with GHB/GBL consumption. To supplement the currently available data, a rapid gas chromatography-mass spectrometry method was developed and validated for the analysis of GHB (following acidic conversion to GBL) and used to analyze urine samples collected from 1126 women (mean = 0.84 mg/L, median = 0.68 mg/L, range = 0.00-5.5 mg/L). GHB concentrations were shown to be independent of urinary pH (within the range 4.6-9.3), age (within the range 18-35 years), body mass index (within the range 13.8-36.3), and race. Adjusting GHB concentrations with respect to urinary specific gravity had little effect on the mean value (0.91 mg/L) and range (0.0-7.76 mg/L), although a statistically significant trend of increasing GHB concentration with specific gravity could be observed. Our results can be taken to offer further support for the 10 mg/L discriminant limit for GHB administration in antemortem urine samples.

AB - γ-Hydroxybutyrate (GHB) and its metabolic precursor γ-butyrolactone (GBL) are often implicated in cases of drug-facilitated sexual assault (DFSA), although definitive confirmation of GHB/GBL ingestion is complicated by GHB's endogenous nature and rapid elimination following ingestion. Multiple studies have attempted to establish a discriminant limit (generally 10 mg/L) above which urinary GHB concentrations can be considered consistent with GHB/GBL consumption. To supplement the currently available data, a rapid gas chromatography-mass spectrometry method was developed and validated for the analysis of GHB (following acidic conversion to GBL) and used to analyze urine samples collected from 1126 women (mean = 0.84 mg/L, median = 0.68 mg/L, range = 0.00-5.5 mg/L). GHB concentrations were shown to be independent of urinary pH (within the range 4.6-9.3), age (within the range 18-35 years), body mass index (within the range 13.8-36.3), and race. Adjusting GHB concentrations with respect to urinary specific gravity had little effect on the mean value (0.91 mg/L) and range (0.0-7.76 mg/L), although a statistically significant trend of increasing GHB concentration with specific gravity could be observed. Our results can be taken to offer further support for the 10 mg/L discriminant limit for GHB administration in antemortem urine samples.

KW - Young Adult

KW - Reference Values

KW - Humans

KW - Hydrogen-Ion Concentration

KW - Aging

KW - Specific Gravity

KW - Algorithms

KW - Calibration

KW - Body Mass Index

KW - Forensic Medicine

KW - Analytic Sample Preparation Methods

KW - Adult

KW - Gas Chromatography-Mass Spectrometry

KW - Adolescent

KW - Sodium Oxybate

KW - Female

U2 - 10.1093/jat/34.9.555

DO - 10.1093/jat/34.9.555

M3 - Article

C2 - 21073808

VL - 34

SP - 555

EP - 561

JO - Journal of Analytical Toxicology

JF - Journal of Analytical Toxicology

IS - 9

ER -