Detection of gamma-hydroxybutyrate in hair: Validation of GC–MS and LC–MS/MS methods and application to a real case

Abstract

a b s t r a c tA gas chromatography-mass spectrometry (GC-MS) and a liquid chromatography tandem mass spectrometry (LC-MS/MS) method were validated for quantifying endogenous and exogenous hair concentrations of gamma-hydroxybutyrate (GHB). The GC-MS method is based on overnight extraction of 25 mg hair in NaOH at 56 • C, liquid/liquid extraction in ethylacetate and trimethylsylil derivatization; analysis is by electron ionization and single ion monitoring of three ions. The LC-MS/MS method entails a rapid digestion of 25 mg hair with NaOH at 75 • C for 40 min, liquid/liquid extraction in ethylacetate and reconstitution of the extract in the LC mobile phase; negative ion electrospray ionization and multiple reaction monitoring (MRM) analysis are employed for the LC-MS/MS detection. In both cases, GHB-d6 is used as an internal standard. The endogenous amount in "blank" hair are estimated by the standard addition method. Limits of detection are 0.4 and 0.5 ng/mg for GC-MS and LC-MS/MS respectively, while the limit of quantification (LOQ) is 0.6 ng/mg for both methods; the GC-MS method proved to be linear in the range 1-50 ng/mg whereas linearity was demonstrated from 0.6 to 50 ng/mg for the LC-MS/MS; imprecision and inaccuracy were always lower than 23% for quality controls samples. The two methods were applied to a real case of a man addicted to GHB; the drug concentration in segments from 17 cm hair strand well correlated with self-reported use of GHB in different periods of his life. Performances of the two methods were similar.

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

“…[14,15] The segmental analysis of hair samples collected one month after the oral administration of a single dose of GHB in 12 healthy volunteers, showed the highest concentration in the second segment of all cases and its mean concentration is 4.45 times (95% C.I. [14,15] The segmental analysis of hair samples collected one month after the oral administration of a single dose of GHB in 12 healthy volunteers, showed the highest concentration in the second segment of all cases and its mean concentration is 4.45 times (95% C.I.…”

Hair testing of GHB: an everlasting issue in forensic toxicology

“…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.…”

“…Several analytical methods have been published for GHB analysis in hair [7-9, 12-18, 20, 24, 26], using different techniques: GC-MS [7,14,18], GC-MS/MS [8,9,13,20], When a GHB-FSA case is suspected Report, when available, the approximate interval of time between the accident and hair sampling excluding eventual previous exposure to GHB (besides the one for which the analysis is required), which can affect the results of the analysis It is necessary to take into account the onset of clinical symptoms, which must fit with a short duration of the sedative effects (typically 2-3 h)…”

“…The measurement of the hair growth during the month between the first sampling (Time 0) and the second one to carefully determine what should be the 'targeted segment' Segmental hair analysis has to be performed together with the calculation of the ratio between the targeted segments and the others with the exclusion of the first one Each subject has to be used as his/her own control [12,[14][15][16][17] and UHPLC-MS/MS [24,26]. The majority of these methods included only quali-quantitaive determination of GHB.…”

“…In 2012 Bertol et al [14] presented a case involving a 40-year-old man with a long history of GHB abuse and abstinence in the previous 2 months due to house arrest. A 17 cm long hair shaft was taken from the posterior vertex of the head and cut into 1 cm segments for the first 3 cm and then into 2 cm segments for the remaining proximal 14 cm.…”