Interpreting GHB concentrations in hair: can a cut-off be established? (original) (raw)
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Variation of intraindividual levels of endogenous GHB in segmented hair samples
Forensic Science International, 2019
Gamma-hydroxybutyrate (GHB) belongs to a group of substances that may be used in drug-facilitated crime (DFC). It is also an endogenous substance. There is a dispute whether or not a single exposure to GHB can be detected in hair. The first aim of this study was to develop and validate a method for the sensitive detection of base levels of GHB in hair. The second aim was to collect analytical data of 88 volunteers (62 females/26 males) not claiming any exposure to GHB and discuss the results in the context of the identification of a potential single exposure in cases of DFC. Furthermore hair samples from a male volunteer, who took GHB twice within 8 weeks, were analysed and the results were discussed with regard to mean values of endogenous GHB analysed in this study. Hair was digested under alkaline conditions, and GHB was isolated using liquid-liquid extraction. LC-MS/MS was performed using Electrospray ionization in the negative mode, multiple reaction monitoring, and a deuterated internal standard (GHB-D6). Segmental hair analysis revealed mean concentrations of 0.673 ng/mg or 0.676 ng/mg (without first segment) in females and 0.935 ng/mg or 0.932 ng/mg (without first segment) in males. Combined mean values were 0.751 ng/mg and 0.752 ng/mg (without first segment). In one individual's hair single doses of 2 g GHB did not lead to an increase compared to his base levels. The limits of detection and quantitation in human hair were 0.1 ng/mg and 0.3 ng/mg, respectively. Accuracy at 0,25 ng/mg, 2,5 ng/mg and 25 ng/mg was determined to be 94% or higher for all levels and intra-assay CVs at these concentrations were always lower than 7% (n = 5). β-hydroxybutyrate (BHB) and glycine did not produce an interference. Recovery at 1 ng/mg and 25 ng/mg GHB was 23% and 13% and Matrix effects were calculated to be 77% and 89% respectively.
Gammahydroxybutyrate in hair of non-GHB and repeated GHB users: A new and optimized method
Forensic Science International, 2018
Gamma-hydroxybutyric acid (GHB) is a short-chain fatty acid used recreationally as a drug of abuse due its strong suppressive effect on the central nervous system.The detectionwindow of GHB in blood and urine is very narrow (t1/2 = 30 min) but can be substantially prolonged using alternative matrices such as hair. We here present a newly developed and limited validated method with a solid phase extraction (SPE) using GC-MS/MS to determine concentrations of GHB in hair samples. The soft extraction technique (water and 90 min ultrasonic bath) preserves GHB with a highyield and clean extracts. In addition, endogenous GHB can be detected in hair of non-GHB users. However, little is known about GHB concentrations in hair of abstinent, frequent and chronic GHB users. Therefore, we present data from hair samples of healthy volunteers to evaluate the proposed endogenous GHB ranges, and from GHB-dependent patients to address GHB concentrations in hair with GHB intake. In 20 non-GHB users, a mean endogenous concentration of 1.1 AE 0.6 ng/mg hair (range of 0.3-2 ng/mg) was found. In GHB-dependent patients, concentrations between 6.3-239.6 ng/mg hair were found, with no correlation between concentrations in hair and dose of GHB intake. In summary, we present a new and limited validated method, adequately sensitive for the detection of GHB in hair, as well as first-time measurements of GHB concentrations in dependent patients in order to better understand the relationship between the frequency of use/dose and concentrations observed in hair samples.
Drug testing and analysis, 2014
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 samp...
2012
A 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.
Simultaneous determination of GHB and EtG in hair using GCMS/MS
Drug Testing and Analysis, 2011
A gas chromatographic tandem mass spectrometric (GCMS/MS) method for simultaneously determining trace concentrations of gamma-hydroxybutyrate (GHB) and ethyl glucuronide (EtG) in hair has been developed. Multiple reaction monitoring (MRM) was used to detect precursor and product ions of GHB, (233 and 147) and EtG (261 and 143) following anion exchange solid phase extraction and derivatization with N,O-bis[trimethylsilyl]trifluoroacetamide (BSTFA). Deuterated standards of GHB and EtG were used as internal standards. The assay produced excellent linearity (r 2 > 0.99) and sensitivity. The lower limit of quantitation (LLOQ) was 10 pg/mg for EtG assuming a 20 mg hair sample. The method has been used to investigate cases of suspected drug facilitated assault as well as being used to identify heavy alcohol consumption in a group of volunteers.
Toxics
Ethyl glucuronide (EtG) is a non-volatile, non-oxidative, hydrophilic, and stable ethanol phase II metabolite. EtG is produced through ethanol glucuronidation by UDP-glucuronosyltransferase (UGT), a phase II enzyme. EtG can be extracted from different biological matrices, including keratin ones, such as hair or nails. The purpose of this scoping review is to describe the relationship between EtG levels in hair and some of the most common and frequent pathological conditions and verify whether different reference cut-offs in relation to various pathologies have been identified in the scientific literature. In fact, in-depth knowledge of the influence of pathologies, such as diabetes mellitus, hepatic and renal dysfunction, on EtG production and its storage in keratin matrices would allow a more appropriate interpretation of obtained data and rule out false positives or false negatives. This scoping review is based on bibliographic research carried out on PubMed regarding the quantifi...
International journal of legal medicine, 2016
Gamma-hydroxybutyric acid (GHB) is an endogenous compound which has a story of clinical use and illicit abuse since the 1960's. The possibility to use a multi-sample approach for GHB evaluation, including whole blood and hair, to better characterize a forensic toxicology case and evaluate a possible causal association with the death is an exciting up-to-date issue. In addition, its post-mortem behaviour, namely regarding degradation and metabolism, has been increasingly investigated as a putative biomarker for post-mortem interval (PMI) estimation. Thus, in order to contribute to clarification of this specific aspect, whole blood and hair post-mortem GHB levels were evaluated in 32 real cases with previous information on death and autopsy data. The results obtained suggest that the PMI (until 5 days between death and sampling) influences GHB whole blood concentration, but not GHB levels in hair samples. No differences were encountered for the other parameters evaluated, includin...
Influence of Body Mass Index on Hair Ethyl Glucuronide Concentrations
Alcohol and Alcoholism, 2016
Aim: Analysis of ethyl glucuronide (EtG) concentrations in hair is increasingly used to estimate the consumption of alcohol of the prior months. Linear correlations between the amount of alcohol consumed and the concentration of EtG in hair have been reported, and several variables that may influence this correlation have been investigated: e.g. cosmetic hair treatments, gender influences or hair color. Here, we investigate the influence of body mass index (BMI) on this correlation. Methods: A post hoc analysis on the influence of BMI on the relation between amounts of alcohol consumed and the measured EtG concentrations in hair in 199 participants. Results: Our data show higher EtG concentrations in participants with high BMI (≥25) compared to participants with low BMI (<25) (P = 0.001) across a wide range of amounts of alcohol consumed. Conclusions: We conclude that BMI should be taken into account when interpreting hair EtG concentrations. Short summary: Ethyl glucuronide concentrations in hair (hEtG) can be used to estimate the consumption of alcohol of the prior months. Body mass index (BMI) influences this relation and BMI should be taken into account when interpreting hEtG concentrations in participants with high BMI (≥25) compared to participants with low BMI (<25).
Proceedings of the Ninth World Congress for Hair Research (2015)
Journal of Investigative Dermatology Symposium Proceedings, 2017
Faculty of the Ninth World Congress of Hair Research* OVERVIEW There is growing research interest in the hair follicle as a model system because of the ease of access for study and the ability to use a wide variety of technologies, including sophisticated imaging techniques, to watch hair follicle growth in real time. The follicle is one of the most proliferative organs/cells, along with the bone marrow and gastrointestinal tract. Therefore, with greater understanding of hair cycling, cells outside the follicle that influence the cycle, auxiliary cells, inflammation, and other factors, major crosstransfer of that knowledge to other organ systems and diseases, such as autoimmune disease, asthma, and allergies, will be possible.
Journal of pharmaceutical and biomedical analysis, 2018
Quantitative determination of ethyl glucuronide in keratin matrix, particularly in hair samples, provides a significant contribution to the evaluation of the extent of ethanol intake. The first-choice method to carry out this analysis is LC-MS/MS, but other techniques may be used. The aim of this work is: a) to develop and validate a GC-MS/MS method for ethyl glucuronide determination in hair; b) to compare GC-MS/MS and LC-MS/MS in analysis of real samples; c) to compare EtG concentration obtained after hair cutting and pulverization. About 30 mg hair samples were washed, pulverized and soaked in 1 ml deionized water. After incubation, the solution was purified through a SPE anion exchange cartridge; the eluate was dried under nitrogen stream, derivatized with PFPA and reconstituted in n-hexane. Then, the sample was injected in the GC-MS/MS system, operating in negative chemical ionization mode and in selected reaction monitoring. The two most intense transitions were used to monito...