Determination of gamma-hydroxybutyrate (GHB) and its precursors in blood and urine samples: a salting-out approach

Gamma-hydroxybutyrate (GHB) is an increasingly popular drug of abuse that causes stimulation, euphoria, anxiolysis or hypnosis, depending on the dose used. Low doses of the drug are used recreationally, and also implicated in drug-facilitated sexual assaults. Because of the unusually steep dose-response curves, accidental GHB overdosing, leading to coma, seizures or death can occur. Being a controlled substance, GHB is often substituted with its non-scheduled precursors gamma-butyrolactone (GBL) and 1,4-butanediol (BD), which are rapidly metabolized into GHB in the body. Here we describe an assay for GHB, GBL and BD in blood and/or urine samples. GHB and BD were extracted from diluted 200 microL aliquots of samples with t-butylmethylether (plus internal standard benzyl alcohol) in test tubes preloaded with NaCl. After acidification and centrifugation the solvent phase was transferred to a test tube preloaded with Na(2)SO(4), incubated for 30 min, centrifuged again, and evaporated in vacuum. The residue was mixed with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA) in acetonitrile, and injected into a GC-MS. When analyzing GBL, the salting-out step was omitted, and analysis was performed with a GC-FID apparatus. As revealed by the validation data this procedure is suitable for quantitative determination of GHB and its precursors in blood and/or urine samples.     

Validated method for the simultaneous determination of Δ-THC and Δ-THC-COOH in oral fluid, urine and whole blood using solid-phase extraction and liquid chromatography–mass spectrometry with electrospray ionization

A fully validated, sensitive and specific method for the extraction and quantification of Δ⁹-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Δ⁹-THC (THC-COOH) and for the detection of 11-hydroxy-Δ⁹-THC (11-OH THC) in oral fluid, urine and whole blood is presented. Solid-phase extraction and liquid chromatography–mass spectrometry (LC–MS) technique were used, with electrospray ionization. Three ions were monitored for THC and THC-COOH and two for 11-OH THC. The compounds were quantified by selected ion recording of m/z 315.31, 329.18 and 343.16 for THC, 11-OH THC and THC-COOH, respectively, and m/z 318.27 and 346.26 for the deuterated internal standards, THC-d₃ and THC-COOH-d₃, respectively. The method proved to be precise for THC and THC-COOH both in terms of intra-day and inter-day analysis, with intra-day coefficients of variation (CV) less than 6.3, 6.6 and 6.5% for THC in saliva, urine and blood, respectively, and 6.8 and 7.7% for THC-COOH in urine and blood, respectively. Day-to-day CVs were less than 3.5, 4.9 and 11.3% for THC in saliva, urine and blood, respectively, and 6.2 and 6.4% for THC-COOH in urine and blood, respectively. Limits of detection (LOD) were 2 ng/mL for THC in oral fluid and 0.5 ng/mL for THC and THC-COOH and 20 ng/mL for 11-OH THC, in urine and blood. Calibration curves showed a linear relationship for THC and THC-COOH in all samples (r² > 0.999) within the range investigated.The procedure presented here has high specificity, selectivity and sensitivity. It can be regarded as an alternative method to GC–MS for the confirmation of positive immunoassay test results, and can be used as a suitable analytical tool for the quantification of THC and THC-COOH in oral fluid, urine and/or blood samples.     

化学显色法快速筛选饮料及尿液中γ-羟基丁酸和γ-丁内酯

目的建立化学显色法快速筛选饮料及尿液中γ-羟基丁酸(GHB)及其前体γ-丁内酯(GBL)的方法。方法在酸性条件下GHB转化为GBL,GBL和盐酸羟胺在碱性条件下生成γ-羟基丁酰羟胺,γ-羟基丁酰羟胺在酸性条件下和三氯化铁反应,生成紫红色的络合物。结果饮料中GHB最低检出浓度为0.5～2mg/mL,低于常见滥用质量浓度。该方法也可以用于尿液分析,最低检出质量浓度为0.5mg/mL。考察了常见有机溶剂和麻醉镇静药物的干扰。结论该方法简单、安全、快速,为临床和法庭科学实验室快速筛选GHB和GBL提供了便利。     

1H NMR analysis of GHB and GBL: further findings on the interconversion and a preliminary report on the analysis of GHB in serum and urine

A 1H nuclear magnetic resonance (1H NMR) method for the determination of gamma-hydroxybutyric acid (GHB) and gamma-hydroxybutyrolactone (GBL) in human serum and urine using spiked samples has been developed. The method gives linear responses (correlation coefficients of 0.99 or greater) over the concentration range 0.01 mg/mL to 4.0 mg/mL in urine and 0.3 mg/mL to 2.0 mg/mL in serum. No sample pretreatment is required. Studies of the chemical interconversion of GBL and GHB showed hydrolysis of GBL to be rapid at pH 11.54, slower and less complete (30% hydrolysis) at pH 2.54 and slowest at pH 7.0, reaching 30% hydrolysis in about 40 days. No esterification of GHB was observed at any pH.     

The chemical interconversion of GHB and GBL: forensic issues and implications.

In this work, the interconversion of GHB and GBL in a variety of aqueous media was studied. The effects of solution pH and time were determined by spiking GHB or GBL into pure water and buffered aqueous solutions, and determining the GHB and GBL contents at various time intervals. The degree of GBL hydrolysis to GHB was determined for several commercial aqueous-based GBL products, and further studied as a function of time. The effects of temperature and time were also determined for five commercial beverages spiked with GHB or GBL. GHB and GBL contents were determined using high performance liquid chromatography (HPLC). GHB and/or GBL confirmations were made using gas chromatography-mass spectrometry (GC-MS) and/or infrared spectroscopy (IR). Solution pH, time, and storage temperature were determined to be important factors affecting the rate and extent of GBL hydrolysis to GHB. Under strongly alkaline conditions (pH 12.0), GBL was completely converted to GHB within minutes. In pure water, GBL reacted to form an equilibrium mixture comprising ca. 2:1 GBL:GHB over a period of months. This same equilibrium mixture was established from either GHB or GBL in strongly acidic solution (pH 2.0) within days. A substantial portion of GBL (ca. 1/3) was hydrolyzed to GHB in aqueous-based GBL products, and in spiked commercial beverages, after ambient storage for a period ranging from several weeks to several months. Heat increased and refrigeration decreased the rate of GBL hydrolysis relative to ambient conditions. These studies show that hydrolysis of GBL to GHB does occur in aqueous-based solutions, with samples and time frames that are relevant to forensic testing. Implications for forensic testing and recommendations are discussed.     

The GC–MS detection and characterization of reticuline as a marker of opium use

Reticuline (a precursor of opium alkaloids) was detected and characterised as its trimethylsilyl ethers, acetyl esters and methyl ethers by GC–EIMS and GC–CIMS in opium and the urine of opium users after hydrolysis by acid or β-glucuronidase as coextractive of morphine. Because this compound cannot be detected in heroin and poppy seeds, it is suggested as a differentiating marker between opium and heroin use, opium and poppy seeds use, or opium and “pharmaceutical” codeine use in cases when opiate use has been confirmed by detection of morphine and codeine in the urine. As well as being a constituent of opium, reticuline in the urine of opium users may also result from the metabolic demethylation of the three other benzyltetrahydroisoquinoline opium alkaloids: codamine, laudanosine and laudanine.     

The reactivity of gamma-hydroxybutyric acid (GHB) and gamma-butyrolactone (GBL) in alcoholic solutions

In this work the stability of GBL (gamma-butyrolactone) and GHB (gamma-hydroxybutyric acid) in alcoholic media was studied. Under acidic conditions the GBL will react with ethanol or methanol to give the corresponding ethyl and methyl esters of GHB. It can be seen that ester formation is dependent on the type of alcohol, the alcohol content of the solution, and the pH of the solution. Under the same conditions it was shown that GHB does not give rise directly to the corresponding ester when merely in the presence of an alcohol; however the ester will be formed if the conditions are present for conversion of GHB to GBL followed by subsequent reaction with alcohol. In alcoholic beverage samples spiked with GBL the expected conversion to GHB occurred, and the formation of the ethyl ester of GHB was also seen in some samples. Wine samples were analyzed for the presence of the ethyl ester of GHB, and the effect of adding GHB/GBL to hot beverages was studied.     

Simultaneous analysis of gamma-hydroxybutyric acid, gamma-butyrolactone, and 1,4-butanediol by micellar electrokinetic chromatography

A micellar electrokinetic chromatography (MEKC) method was optimised for simultaneous analysis of gamma-hydroxybutyric acid (GHB), gamma-butyrolactone (GBL), and 1,4-butanediol (BD). Best conditions for separation and baseline stability were achieved using a carrier electrolyte comprising 30.0mM sodium barbital and 150.0mM sodium dodecyl sulphate (SDS) at pH 10.2. Calibration functions were linear, giving correlation coefficients (r(2)) >0.998 for the three target compounds. Limits of detection (LOD) defined as three times the noise, were 5.1mg/l, 0.34 and 0.25g/l for GHB, GBL and BD, respectively. The repeatability of migration times and peak areas, expressed as the R.S.D. (n = 9) was better than 0.41 and 3.05%, respectively. Some casework samples were analysed using the optimised conditions.     

The presence of gamma-hydroxybutyric acid (GHB) and gamma-butyrolactone (GBL) in alcoholic and non-alcoholic beverages

Gamma-hydroxybutyric acid (GHB) and its precursor gamma-butyrolactone (GBL) are regularly implicated in instances of surreptitious drug administration, particularly in beverages (so-called "spiked drinks"). In order to assist in the interpretation of cases where analysis of the actual beverage is required, over 50 beverages purchased in the UK were analysed for the presence of GHB and GBL. It was found that naturally occurring GHB and GBL were detected in those beverages involving the fermentation of white and particularly red grapes. No GHB or GBL was detected in other drinks such as beer, juice, spirits or liqueurs. GHB/GBL was detected in red wine vermouth (8.2 mg/L), sherry (9.7 mg/L), port (GBL), red wine (4.1-21.4 mg/L) and white wine (<3-9.6 mg/L). The presence of GHB/GBL did not appear to be influenced by the alcohol content or the pH of the beverage. In addition, the concentration in wines did not appear to be related to the geographical origin of the grape type. This is believed to be the first published data concerning the endogenous presence of GHB and GBL in the beverages described.     

A novel method for GHB detection in urine and its application in drug-facilitated sexual assaults

A confirmation procedure for the identification and quantification of gamma-hydroxybutyric acid (GHB) in urine is presented. This method is unique in that it does not involve the conversion of GHB to the gamma-butyrolactone (GBL). The urine samples were extracted using ethyl acetate, evaporated and derivatized with N, O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS), and analyzed by gas chromatography-mass spectrometry. Quantification was performed using selective ion monitoring (SIM), using GHB-d(6) as the internal standard. This method is simple and provides excellent linearity and sensitivity for GHB in urine.     

Fatal Overdose of Gamma‐hydroxybutyrate Acid After Ingestion of 1,4‐Butanediol

We report a case of fatal intoxication from 1,4‐butanediol (1,4‐BD), which was ingested by a young and “naïve” gamma‐hydroxybutyrate (GHB) consumer during a party with the co‐ingestion of alcohol, cannabis, and methylene‐dioxy‐methamphetamine. The following drug concentrations were found using gas chromatography coupled with mass spectrometry on autopsy samples and on a cup and a glass found at the scene: 20,350 mg/L (bottle) for 1,4‐BD; 1020 mg/L (femoral blood), 3380 mg/L (cardiac blood), 47,280 mg/L (gastric content), and 570 mg/L (vitreous humor) for GHB. The concentration of GHB is difficult to interpret in forensic cases due to the possibility of an endogenous production of GHB. The variable tolerance of the user may also modify the peri‐ and postmortem GHB concentrations. This case underscores the need to have many different sources of toxicology samples analyzed to avoid the hypothesis of endogenous production of GHB.     

GHB free acid: I. Solution formation studies and spectroscopic characterization by 1HNMR and FT-IR

In forensic evidence, gamma-hydroxybutyric acid (GHB) has frequently been encountered in one of its salt forms (gamma-hydroxybutyrate), but has also been encountered in its free acid form (GHB). Owing to the physical properties, encounters of the free acid have been largely restricted to forensic exhibits comprising aqueous solutions, such as acidic beverages that have been "spiked" or formulated with GHB salts or gamma-butyrolactone (GBL). The analysis of GHB free acid presents particular difficulties including the potential for altering the original proportions of GHB free acid, GHB carboxylate, and GBL in the course of analysis, and discrimination between GHB free acid and carboxylate forms. In this work, the formation of GHB free acid in aqueous solutions (water and/or D2O) was studied as a function of solution pH. Proton nuclear magnetic resonance (1HNMR) and Fourier-transform infrared spectrometry (FT-IR) measurements were obtained on freshly prepared mixtures of NaGHB and HCl stock solutions representing a series of points along the GHB titration curve. Both 1HNMR and FT-IR were shown to track the changing proportions of GHB free acid and carboxylate forms as a function of pH, while simultaneously monitoring for the formation of the lactone (GBL). The results were consistent with acid-base conversion behavior for a carboxylic acid. 1HNMR was shown to provide an ideal means for analysis of aqueous-based GHB/GBL forensic exhibits based on simple dilution of the neat liquid exhibit, without altering the original proportions of GHB free acid, carboxylate, and GBL in the samples.     

Determination of gamma-hydroxybutyrate in water and human urine by solid phase microextraction-gas chromatography/quadrupole ion trap spectrometry

A simple method of detection was developed for gamma-hydroxybutyrate (GHB). The method involves the derivatization of GHB using a hexyl-chloroformate procedure in aqueous media (such as water or urine), extraction of the derivatization product directly from the sample using solid-phase microextraction, and subsequent separation and detection with gas chromatography quadrupole ion trap mass spectrometry. The deuterated form of GHB (GHB-D6) is used as an internal standard for quantitation. The method was linear for GHB-spiked pure water samples from 2 to 150 microg/mL GHB with a detection limit of 0.2 microg/mL. Spiked urine samples showed linearity from 5 to 500 microg/mL GHB with a detection limit of 2 microg/mL. The SPME-GC/MS method is applied to actual case samples, and the results are compared to those values obtained using a conventional GC/MS method. Sensitivity and linearity are comparable to those seen using traditional methods of separation, yet the SPME method is superior due to the simplicity, speed of analysis, reduction in solvent waste, and ability to differentiate between GHB and gamma-butyrolactone (GBL).     

Evaluation of the Cozart RapiScan drug test system for opiates and cocaine in oral fluid

The purpose of this study was to evaluate the efficiency of the Cozart^® RapiScan (CRS) drug test system for detecting opiates and cocaine in oral fluid. Oral fluid samples were collected using the Cozart^® RapiScan collection system from 358 donors who were receiving treatment for their addiction and were monitored for drug misuse. A further 103 oral fluid samples were collected from volunteer donors who were not drug users. The samples were analyzed in the laboratory using the two-panel Cozart^® RapiScan cartridge for opiates and cocaine and confirmed using gas chromatography–mass spectrometry (GC–MS). The samples were stored frozen at −20 °C until analysis by GC–MS. The overall accuracy of the CRS for both opiates and cocaine was 100%. Samples spiked at 50% above and below the cut-off consistently gave negative and positive results respectively. A total of 88 samples were positive for various opiates and 111 samples were positive for cocaine and/or its metabolites. The CRS for opiates and cocaine in oral fluid, using a cut-off of 30 ng/mL morphine or benzoylecgonine equivalents in neat oral fluid, had overall efficiencies of 98% and 99%, respectively, versus GC–MS. A series of potential adulterants of oral fluid were evaluated and shown not to alter the outcome of the test result.     

尿液、血液中γ-羟丁酸的气质联用法分析

目的为尿液、血液中γ-羟丁酸(gamma-hydroxybutyricacid,GHB),γ-羟丁酸内酯(gamma-butyrolactone,GBL)和1,4-丁二醇(1,4-butanediol,1,4-BD)的鉴定提供方法和依据。方法100μl尿液或血液以GHBd6为内标,经乙酸乙酯提取、BSTFA衍生化后,用GC／MS法分析。结果测尿液中内源性GHB的线性范围是20-800ng／ml,R2=0.9995,最低检出限为10ng／ml(S／N≥3);测尿液、血液中外源性GHB的线性范围为5-60μg／ml,R2分别为0.9999和0.9928。相对回收率为99％-104％。以所建方法测定了健康志愿者尿液中内源性GHB含量,并考察了健康受试者外源性GHB的代谢情况。结论所建方法准确、便捷、省时、选择性好,适用于法医毒物学鉴定。     

Evaluation of the IDS One-Step™ ELISA kits for the detection of illicit drugs in hair

This work presents the validation of a new immunological assay, the One-Step™ enzyme-linked immunosorbent assay (ELISA) tests from International Diagnostic Systems Corp. for the screening of drugs of abuse (cannabis, amphetamines, opiates, and cocaine) in human hair, with subsequent GC–MS confirmation. After decontamination and segmentation into small pieces, 50 mg of hair sample were incubated in 1 ml of methanol during 16 h at 40 °C. A 100 μL aliquot was collected and evaporated to dryness in presence of 100 μL of methanol/hydrochloric acid (99:1, v/v) to avoid amphetamines loss. The dried extract was dissolved in 100 μL of the “sample and standard diluent” solution included in the kit. This solution was submitted to analysis according to the recommended instructions of the manufacturer. During the validation phase, GC–MS confirmations were conducted according to our fully validated and published methods for opiates, cocaine, cannabis, and amphetamines determinations in hair. In a last development step, these procedures were slightly modified to directly confirm ELISA results by GC–MS using the methanolic extract. Ninety-three specimens were simultaneously screened by the ELISA tests (103 for tetrahydrocannabinol (THC)) and confirmed by GC–MS. Twenty were found positive for cannabis (THC: 0.10–6.50 ng/mg), 21 for cocaine (0.50–55.20 ng/mg), 24 for opiates (6-acetylmorphine (6-AM): 0.20–11.60 ng/mg, MOR: 0.20–8.90 ng/mg, codeine (COD): 0.20–5.90 ng/mg), and 13 for amphetamines (AP: 0.20 and 0.27 ng/mg, methamphetamine (MAP): 0.30 and 1.10 ng/mg, methylenedioxymethamphetamine (MDMA): 0.22–17.80 ng/mg). No false negative results were observed according to the Society of Hair Testing's (SoHT) cutoffs (0.5 ng/mg for cocaine, 0.2 ng/mg for opiates and amphetamines, and 0.1 ng/mg for THC). The One-Step™ ELISA kits appear suitable due to their sensitivity and specificity for drug of abuse screening in hair. This technology should find interest in workplace drug testing or driving license regranting, especially when many samples have to be tested with a high rate of negative samples, as ELISA is an easy and high-throughput method.     

Time-dependent immunohistochemical detection of proinflammatory cytokines (IL-1β, IL-6, TNF-α) in human skin wounds

The proinflammatory cytokines interleukin-1beta (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α) hold important functions in the early and late courses of inflammation, trauma and wound healing. In the present study, human skin wounds due to sharp force (n=105) were collected during surgery and autopsy. The wound age mainly varied from several minutes to 5 h, some specimens aged up to 6 weeks. Control specimens from uninjured skin were available in each case. After preparation of cryostat sections, immunohistochemistry was performed according to the APAAP technique, using monoclonal and polyclonal antibodies. The results were evaluated semiquantitatively. All markers were weakly expressed in normal human skin constitutively. However, the staining pattern changed significantly in vital wounds concerning epidermal layers, subepidermal cells, vessels and sweat glands. IL-1β and IL-6 showed enhanced expression after 15 and 20 min at the earliest (increase of epidermal reactivity). After 30–60 and 60–90 min, respectively, marked expression was observed with these markers. Similar alterations were detectable with TNF-α after 15 and 60–90 min. The reactivity of all three markers persisted over several hours, then decreased to basal levels again and sometimes reappeared after days and in granulation tissue. Leukocytes reacting with IL-1β and IL-6 appeared after approximately 2 h. Conclusion: proinflammatory cytokines can serve as a useful tool for the estimation of vitality and wound age, in particular in the early post-traumatic interval prior to leukocyte reaction. Autolysis did not play a role in the samples investigated (postmortem interval up to 8 days). Problems could sometimes rise from constitutive expression. Therefore, it is recommended to examine control samples from the same individual and to compare the reactivity with wound specimens.     

GC–MS studies on acylated derivatives of 3-methoxy-4-methyl- and 4-methoxy-3-methyl-phenethylamines: Regioisomers related to 3,4-MDMA

A series of side chain regioisomers of 3-methoxy-4-methyl- and 4-methoxy-4-methyl-phenethylamines have mass spectra essentially equivalent to the controlled drug substance 3,4-methylenedioxymethamphetamine (3,4-MDMA), all have molecular weight of 193 and major fragment ions in their electron ionization mass spectra at m/z 58 and 135/136. The acetyl, propionyl and trifluoroacetyl derivatives of the primary and secondary regioisomeric amines were prepared and evaluated in GC–MS studies. The mass spectra for these derivatives were significantly individualized and the resulting unique fragment ions allowed for specific side chain identification. The trifluoroacetyl derivatives provided more fragment ions for molecular individualization among these regioisomeric substances. These trifluoroacetyl derivatives showed excellent resolution on a non-polar stationary phase such as Rtx-1.     

A preliminary investigation into the comparison of dissolution/digestion techniques for the chemical characterization of polyurethane foam

Due to their widespread use in domestic and commercial premises, polyurethane foams, as either fragmented or bulk foam, are types of evidence commonly found at crime scenes. The traditional approach to determining the evidential value of polyurethane foam (PF) involves comparing recovered and control fragments under low and high magnification, under various lighting conditions, as well as the comparison of their respective dye spectra. As with most forms of trace evidence, chemical comparison is also desirable. In this work, two approaches to chemically comparing foam fragments were investigated, i.e. inductively coupled plasma–optical emission spectrometry (ICP–OES) analysis of the Tin (Sn) content in different foam types; and gas chromatography–flame ionization detection (GC–FID) analysis of soluble components in PFs mobilized by dichloromethane. Seven different foam types were studied and their Sn content was found to be different. They also produced characteristic GC–FID chromatographic profiles whose compounds were identified with gas chromatography–mass spectrometry (GC–MS) analysis. This study suggests that incorporating chemical data obtained from GC–FID/GC–MS and ICP–OES into a case involving PF could be advantageous, as this will enable the forensic scientist to broaden the comparison between control and recovered fragments, and further assess the strength of the evidence. However, ICP–OES analysis is a destructive technique with a relatively short sample turnaround time, whilst GC–FID analysis is more time-consuming and non-destructive, requiring corroboration with GC–MS data. The values of these two analytical techniques in the forensic chemical characterization of PFs are discussed.     

GHB free acid: II. Isolation and spectroscopic characterization for forensic analysis

A reference standard for gamma-hydroxybutyric acid (GHB) free acid is not commercially available, making its analysis in forensic exhibits more difficult. GHB free acid is typically encountered in aqueous solution and in the presence of the lactone, gamma-butyrolactone (GBL), presenting difficulty in Fourier transform infrared (FT-IR) analysis. The strong infrared (IR) absorptivity of the GBL carbonyl band, the shifting of the GBL carbonyl band in aqueous solutions, and the position of the O-H bend for water can mask the main carbonyl band for GHB free acid. Model solutions of beta-hydroxybutyric acid (BHB) and GBL were studied in order to further understand the masking of the GHB free acid carbonyl band in FT-IR analysis. The use of second derivative FT-IR spectroscopy was shown to provide resolution of the free acid carbonyl band, and a presumptive test for GHB free acid was developed and applied. An extension of this work included preparing, for use as a standard reference material, small amounts (< or = 10 mg) of GHB free acid. Preparation was based on the instantaneous reaction of GHB's sodium salt with a stoichiometric amount of hydrochloric acid in aqueous solution, and subsequent isolation of the free acid in neat liquid form. Both FT-IR and proton nuclear magnetic resonance spectra of the neat reference material were obtained and used to verify its identity. The isolation of GHB free acid from actual forensic exhibits is also presented, with identity confirmation using FT-IR.