Determination of GHB in human hair by HPLC‐MS/MS: Development and validation of a method and application to a study group and three possible single exposure cases

Abstract

Gamma-hydroxybutyrate (GHB) over the last two decades has generated increased notoriety as a euphoric and disinhibiting drug of abuse in cases of drug-related sexual assault and for this reason it is considered a 'date rape' drug. The first aim of this paper was to develop and fully validate a method for the detection of GHB in human hair by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) after liquid-liquid extraction (LLE). The second aim was the application of the method to hair samples of 30 GHB-free users in order to determine the basal level. The results obtained showed no significant differences in endogenous concentrations (p = 0.556) between hair samples of the three groups (black, blonde, and dyed hair) and the age and sex of the subjects did not affect the endogenous levels. Another 12 healthy volunteers, with no previous history of GHB use, were selected and a single dose (25 mg/Kg) was orally administered to all of them and hair samples were collected before the administration of the single dose and other two samples were collected one month and two months later, respectively. The segmental analysis of the latter two samples allowed us to calculate two ratios: 4.45:1 (95% C.I. 3.52-5.63) and 3.35:1 (95% C.I. 2.14-5.18), respectively, which can be recommended as reasonable values for a positive identification of GHB intake. Finally the method was applied to three real cases where a GHB single exposure probably occurred.

Gamma-Hydroxybutyrate (GHB) Content in Hair Samples Correlates Negatively with Age in Succinic Semialdehyde Dehydrogenase Deficiency

“…The GHB range was <0.32-1.00 ng/mg hair in controls, with 0.32 ng/mg representing LOQ. Other investigators have reported higher values, including Goullé et al (2003), 0.32-1.86 ng/mg, n ¼ 61; Bertol et al (2015), 0-5.09 ng/mg, n ¼ 30; and Shi et al (2016), 0.28-4.91 ng/ mg, n ¼ 66. Statistical analysis of GHB concentrations in hair employed the Spearman rank order correlation for nonparametric data, with a post-hoc Bonferroni analysis employing a standard two-way t-test.…”

Hair testing of GHB: an everlasting issue in forensic toxicology

“…In the same year, Bertol et al [16] reported that, due to sweat contamination, GHB concentration in the first 0.5 cm hair segment of a group of non-consumers was statistically higher in comparison to all the other subsequent segments where mean GHB concentration was 1.27 ± 0.73 ng/mg.…”

“…Of the 2304 sources found, only 20 [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] were considered appropriate for the purpose of this paper. A flowchart of the selected papers and inclusion criteria are reported in Figure 1.…”

“…In 2015, Bertol and Busardò and their respective research groups performed a study where hair samples of 30 volunteers were selected and divided according to color (10 samples of black hair, 10 samples of blond hair, and 10 samples of hair dyed with different colors) for the determination of endogenous GHB [16]. GHB was detected in the range between 0 and 5.09 ng/mg.…”

“…Literature searching has identified eight different studies [8,9,15,16,18,[20][21][22] where endogenous GHB values were investigated in hair. The first study by Kintz and collected from 8 males and 16 females [8].…”