Quantitative Analysis of Gamma‐Hydroxybutyrate at Endogenous Concentrations in Hair using Liquid Chromatography Tandem Mass Spectrometry

Abstract: A method capable of quantifying endogenous concentrations of gamma‐hydroxybutyrate (GHB) in human head hair was developed and validated using liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS). Hair was digested under alkaline conditions, and GHB was isolated using liquid–liquid extraction. LC/MS/MS was performed using atmospheric pressure chemical ionization in the negative mode, multiple reaction monitoring, and deuterated internal standard (GHB‐D₆). Linearity was observed between 0.1 and 100 ng/mg GHB (R² = 1.000). The limits of detection and quantitation in human hair were 0.2 and 0.4 ng/mg, respectively. Accuracy at 2 ng/mg and 10 ng/mg was determined to be 97% and 94%, and intra‐assay CVs at these concentrations were 5.2% and 7.4% (n = 4). Beta‐hydroxybutyrate (BHB), alpha‐hydroxybutyrate, gamma‐butyrolactone, and 1,4‐butanediol did not produce an interference, and there was negligible ion suppression or enhancement from the matrix.     

Fatal intoxication with 1,4-butanediol: Case report and comprehensive review of the literature

A fatal case of 1,4-butanediol (1,4-BD) oral ingestion is reported here, in which a 51-year-old man was found dead in his bed. According to the police report, the deceased was a known drug user. A glass bottle labeled (and later confirmed to be) “Butandiol 1,4” (1,4-BD) was found in the kitchen. Furthermore, the deceased's friend stated that he consumed 1,4-BD on a regular basis. The autopsy and histological examination of postmortem parenchymatous organ specimens did not revealed a clear cause of death. Chemical-toxicological investigations revealed gammahydroxybutyrat (GHB) in body fluids and tissues in the following quantities: femoral blood 390 mg/L, heart blood 420 mg/L, cerebrospinal fluid 420 mg/L, vitreous humor 640 mg/L, urine 1600 mg/L, and head hair 26.7 ng/mg. In addition, 1,4-BD was qualitatively detected in the head hair, urine, stomach contents, and the bottle. No other substances, including alcohol, were detected at pharmacologically relevant concentrations. 1,4-BD is known as precursor substance that is converted in vivo into GHB. In the synoptic assessment of toxicological findings, the police investigations and having excluded other causes of death, a lethal GHB-intoxication following ingestion of 1,4-BD, can be assumed in this case. Fatal intoxications with 1,4-BD have seldom been reported due to a very rapid conversion to GHB and, among other things, non-specific symptoms after ingestion. This case report aims to give an overview to the published of fatal 1,4-BD-intoxications and to discuss the problems associated with detection of 1,4-BD in (postmortem) specimens.     

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

γ-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 γ-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 μL 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 Na₂SO₄, 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.     

A hydrophilic interaction liquid chromatography electrospray tandem mass spectrometry method for the simultaneous determination of γ-hydroxybutyrate and its precursors in forensic whole blood

A liquid-chromatography-tandem-mass-spectrometry method using pneumatically assisted electrospray ionisation (LC-ESI-MS/MS) was developed for the simultaneous determination of γ-hydroxybutyric acid (GHB), γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) in human ante-mortem and post-mortem whole blood. The blood proteins were precipitated using a mixture of methanol and acetonitrile, and the extract was cleaned-up by passage through a polymeric strong cation exchange sorbent. Separation of the analytes and their structural isomers was obtained using a column with a zwitterionic stationary phase. Matrix-matched calibrants, combined with isotope dilution, were used for quantitative analysis. GHB was determined in both positive and negative ion modes. The relative intra-laboratory reproducibility standard deviations were better than 10% and 6% for blood samples at concentrations of 2mg/L and 20-150mg/L, respectively. The mean true extraction recoveries were 80% for GHB and greater than 90% for GBL and 1,4-BD at concentration levels of 20-50mg/L. The limits of detection were approximately 0.5mg/L for GHB and GBL, and 0.02mg/L for 1,4-BD in ante-mortem blood. The corresponding lower limits of quantification were less than 1mg/L for GHB and GBL, and less than 0.1mg/L for 1,4-BD. GBL was unstable in whole blood freshly preserved with a sodium fluoride oxalate mixture, but the stability could be improved significantly by preservation with a sodium fluoride citrate EDTA mixture.     

The possible influence of micro-organisms and putrefaction in the production of GHB in post-mortem biological fluid

In recent years, the post-mortem production of the drug of abuse gamma-hydroxybutyric acid (GHB) in biological fluids (e.g. blood and urine) has caused various interpretative problems for toxicologists. Previously, other researchers have shown certain microbial species (Pseudomonas spp. and Clostridium aminobutyricum) possess the necessary enzymes to convert GABA to GHB. A preliminary investigation involving putrefied post-mortem blood indicated there was no observed relationship between "endogenous" GHB concentrations and concentrations of common putrefactive markers (tryptamine and phenyl-2-ethylamine). Microbiological analysis identified the presence of various micro-organisms: Clostridia spp., Escherichia coli, Proteus vulgaris, Enterococcus faecalis and Aeromonoas spp. Equine plasma, human blood and urine samples were inoculated with these and an additional micro-organism (Pseudomonas aeruginosa) and incubated at 22 degrees C for 1 month. Following comparison with control samples and pre-inoculation concentrations, the data indicated an apparent production of GHB in unpreserved P. aeruginosa inoculated blood (2.3 mg/l). All other fluoride-preserved and unpreserved samples (including controls) had GHB concentrations <1mg/l. Although this concentration is lower than is typically associated with "endogenous" post-mortem GHB concentrations, this paper proposes a potential microbial production of GHB with time.     

n‐Ethyl Pentylone‐Related Deaths in Alabama

n‐Ethyl pentylone (NEP) is a chemical substance derived from cathinone. Synthetic cathinones are an evolving group of drugs with stimulating, mind‐altering effects sometimes referred to as novel or new psychoactive substances (NPS). There is scarce information in the medical literature regarding forensic cases in which NEP is detected in toxicological testing. We present four fatalities involving NEP from Alabama in 2017. Deaths were attributed to NEP toxicity in two cases (peripheral blood concentrations of 0.121 and 0.953 mg/L) and injuries caused by gunshot wounds in two cases (peripheral blood concentrations of 0.045 and 0.031 mg/L). One case involving NEP described an individual who exhibited classic CNS‐stimulant induced erratic behavior before being found dead. These cases enhance the forensic literature regarding specific NPS like NEP and provide contextual reference for professionals considering the significance of NEP in toxicological interpretation.     

Determination of Nicotine,Cotinine and Trans‐3′‐Hydroxycotinine using LC/MS/MS in Forensic Samples of a Nicotine Fatal Case by Oral Ingestion of e‐cigarette Liquid,

Nicotine is a potent neurotoxin alkaloid and is used in e‐cigarette liquid. The LC/MS/MS method was linear over 0.01–1.0 mg/L (r² = 0.992–0.995). Limit of detection and limit of quantitation were 0.001 mg/L (S/N = 3) and 0.003 (S/N = 10). The inaccuracy and imprecision were <13.2%. The recoveries were >99.3%. A 39‐year‐old dentist was found dead lying on the floor under the couch in his dental clinic. The concentration of nicotine, cotinine, and trans‐3′‐hydroxycotinine (heart blood/peripheral blood) was analyzed as follows: 87.2/85.2 mg/L (ratio 1.0), 1.4/1.1 mg/L (ratio 1.3), and 0.012/0.0089 mg/L (ratio 1.3), respectively. The concentration of nicotine was determined to be 6734.8 mg/kg in gastric contents and 7262.0 mg/L in remaining e‐liquid. Only, high concentration of nicotine was detected in the gastric contents as well as the two pieces of evidence collected from the death scene. This fatal case resulted from oral ingestion of e‐cigarette liquid. It is estimated that at least 714 mg of nicotine was orally ingested.     

Investigations concerning the threshold value between endogenous and exogenous GHB (liquid ecstasy)

The article describes critical investigations concerning the threshold value between endogenous and exogenous concentrations of gamma-hydroxybutyric acid (GHB/"liquid ecstasy") in human blood. The values of GHB in the blood samples of 50 blood donors and 50 postmortem cases were measured with a validated gas-chromatographic/mass-spectrometric procedure according to the guidelines of the GTFCh (Society of Toxicological and Forensic Chemistry). GHB-concentrations were found to range between 0.11 and 1.56 mg/L (mean value 0.54 mg/L/standard deviation 0.37 mg/L/coefficient of variation 68.4 %) in the donors' blood, and between 2.2 and 116 mg/L (mean value 32.4 mg/L/standard deviation 25.6 mg/L/coefficient of variation 79 %) in the postmortem samples, respectively.     

A Multi-Drug Intoxication Fatality Involving Xyrem® (GHB)

Abstract:  Gamma-hydroxybutyrate (GHB) is best known as a recreational depressant drug, whose use has also been implicated in drug facilitated sexual assault cases. It is also available as a therapeutic agent (Xyrem^®) used for the treatment of daytime sleepiness or cataplexy associated with narcolepsy. This is a report of a case of a 53-year-old woman undergoing treatment with Xyrem^® for narcolepsy. The decedent was also prescribed tramadol, gabapentin, cetirizine, modafinil, carisoprodol, and Xyrem^®. Toxicological analysis of the blood revealed GHB 165.6 mg/L, and 90.7 mg/L in the urine. Blood GHB concentrations in the range 156–260 mg/L have been reported to induce moderately sound sleep. The combined use of central nervous system depressant drugs, together with her problematic sleep apnea, and snoring (both contraindications for GHB use) were determined to have caused this subject's death. The manner of death was determined to be accidental.     

Characteristics and dose-effect relationship of clinical gamma-hydroxybutyrate intoxication: A case series

Gamma-Hydroxybutyrate (GHB) overdoses cause respiratory depression, coma, or even death. Symptoms and severity of poisoning depend on blood-concentrations and individual factors such as tolerance. A retrospective case study was conducted, evaluating GHB intoxication cases. GHB-concentrations in blood and urine were determined by gas chromatography-mass spectrometry (GC-MS) along with, in part, via enzymatic assay. GHB-concentrations, demographic data, and additional drug use, as well as specific clinical information, were evaluated. The correlation between GHB-levels in blood and associated symptoms were examined. In total, 75 cases originating from the Emergency Departments (EDs) of Hamburg and surrounding hospitals were included. Fifty-four of the patients (72%) were male. The mean GHB-concentration in blood was 248 mg/L (range 21.5–1418 mg/L). Out of the group with detailed clinical information (n = 18), the comatose group (n = 10/18) showed a mean of 244 mg/L (range 136–403 mg/L), which was higher than that of the somnolent and awake patients. Of the comatose collective, 70% (n = 7) showed co-use of one or more substances, with the additional use of cocaine being the most frequently detected (n = 5). In conclusion, a moderate dose-effect relationship was observed, although, there was some overlap in dosage concentration levels of GHB in awake and comatose patients. In GHB-intoxication cases, co-use was common as were clinical effects such as acidosis, hypotension, and impact on the heart rate. Timely analytical determination of the GHB-concentration in blood could support correct diagnosis of the cause of unconsciousness.     

GHB. Club drug or confusing artifact?

GHB can be produced either as a pre- or postmortem artifact. The authors describe two cases in which GHB was detected and discuss the problem of determining the role of GHB in each case. In both cases, NaF-preserved blood and urine were analyzed using gas chromatography. The first decedent, a known methamphetamine abuser, had GHB concentrations similar to those observed with subanesthetic doses (femoral blood, 159 microg/ml; urine, 1100 microg/ml). Myocardial fibrosis, in the pattern associated with stimulant abuse, was also evident. The second decedent had a normal heart but higher concentrations of GHB (femoral blood, 1.4 mg/ml; right heart, 1.1 mg/ml; urine, 6.0 mg/ml). Blood cocaine and MDMA levels were 420 and 730 ng/ml, respectively. Both decedents had been drinking and were in a postabsorptive state, with blood to vitreous ratios of less than 0.90. If NaF is not used as a preservative, GHB is produced as an artifact. Therefore, the mere demonstration of GHB does not prove causality or even necessarily that GHB was ingested. Blood and urine GHB concentrations in case 1 can be produced by a therapeutic dose of 100 mg, and myocardial fibrosis may have had more to do with the cause of death than GHB. The history in case 2 is consistent with the substantial GHB ingestion, but other drugs, including ethanol, were also detected. Ethanol interferes with GHB metabolism, preventing GHB breakdown, raising blood concentrations, and making respiratory arrest more likely. Combined investigational, autopsy, and toxicology data suggest that GHB was the cause of death in case 2 but not case 1. Given the recent discovery that postmortem GHB production occurs even in stored antemortem blood samples (provided they were preserved with citrate) and the earlier observations that de novo GHB production in urine does not occur, it is unwise to draw any inferences about causality unless (1) blood and urine are both analyzed and found to be elevated; (2) blood is collected in NaF-containing tubes; and (3) a detailed case history is obtained.     

Death of a 10‐Month‐Old Boy After Exposure to Ethylmorphine

Abstract: Ethylmorphine, an opiate that is partially metabolized to morphine, is a common ingredient in antitussive preparations. We present a case where a 10‐month‐old boy was administered ethylmorphine in the evening and found dead in bed the following morning. Postmortem toxicological analyses of heart blood by gas chromatography‐mass spectrometry and liquid chromatography‐mass spectrometry revealed the presence of ethylmorphine and morphine at concentrations of 0.17 μM (0.054 mg/L) and 0.090 μM (0.026 mg/L), respectively. CYP2D6 genotyping showed that the deceased had an extensive metabolizer genotype, signifying a “normal” capacity for metabolizing ethylmorphine to morphine. The autopsy report concluded that death was caused by a combination of opiate‐induced sedation and weakening of respiratory drive, a respiratory infection, and a sleeping position that could have impeded breathing. This is the first case report where the death of an infant has been linked to ethylmorphine ingestion.     

“Bath Salts” the New York City Medical Examiner Experience: A 3‐Year Retrospective Review

“Bath salts” are synthetic derivatives of cathinones, compounds found in the leaves of Catha edulis, which possesses amphetamine‐like properties. At the New York City Office of Chief Medical Examiner, we conducted a 3‐year retrospective analysis of deaths in which cathinones were detected. Two categories emerged; those in which cathinones were a contributory cause of death (15 cases) and those in which they were an incidental finding (15 cases). Of the former group, 13 were associated with additional intoxicants; two deaths were attributed solely to cathinone intoxication, both survived 10 h: a man whose postmortem blood methylone concentration was 0.71 mg/L and a woman whose postmortem blood ethylone concentration was 1.7 mg/L. In the latter category, there were several individuals who had higher concentrations of cathinones than the above two, the highest being a blood methylone of 4.8 mg/L. Based upon our data and the literature presented, lethal concentrations of cathinones cannot be established.     

Gamma-hydroxybutyric acid stability and formation in blood and urine

Gamma-hydroxybutyric acid (GHB) can cause problems in interpretation of toxicological findings due to its endogenous nature, significant production in tissues after death and potential formation in stored samples. Our study was designed to determine the influence of storage conditions on GHB levels and its possible in vitro formation in blood and urine in cases where no exogenous use of GHB or its precursors was suspected. The samples were prepared by validated method based on liquid-liquid reextraction with adipic acid internal standard and MSTFA derivatization and assayed on a GC-MS operating in EI SIM mode. The first part of the study was performed with pooled blood and urine samples obtained from living and deceased subjects stored with and without NaF (1% w/v) at 4 and -20 degrees C over 8 months. In ante-mortem samples (both blood and urine) no significant GHB production was found. After 4 months of storage, the substantial GHB rise up to 100 mg/Lwas observed in post-mortem blood stored at 4 degrees C without NaF with subsequent gradual decrease in following months. The inhibition of GHB production was apparent during storage in NaF treated frozen blood samples. In post-mortem urine only slight temporary GHB levels were ascertained (up to 8 mg/L). The second part of our study was aimed to analyse 20 individual post-mortem blood samples stored at 4 degrees C for 16-27 days between autopsy and analysis without preservation followed by storage at 4 degrees C with NaF for 4 months. The temporary GHB production with maximum of 28 mg/Lwas detected in some samples.     

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.     

Acute Benztropine Intoxication and Fatality

A woman was found unresponsive with an empty bottle of Cogentin^® prescribed to another. Admitted to an area hospital, her condition steadily declined until death 29 h after admission. Following toxicological screening on hospital (admission) whole blood, the only significant compound detected was benztropine. Benztropine was confirmed at 0.28 mg/L – the highest antemortem blood concentration recorded in a case of toxicity or fatality uniquely associated with benztropine. A second serum antemortem specimen showed a benztropine concentration of 0.19 mg/L. Despite over 24 h in the hospital, benztropine was also found in the postmortem specimens collected at autopsy. Peripheral blood, central blood, liver, and gastric concentrations were 0.47 mg/L, 0.36 mg/L, 9.6 mg/kg, and 44 mg, respectively. These results indicate that benztropine exhibited a potential difference between whole‐blood and serum (plasma) concentrations. Additionally, in consideration of literature data, benztropine was found indicative of a compound prone to at least some postmortem redistribution.     

A Rare Case of Poisoning with a Volatile Substance: Quantitative Determination of n‐Butane in Postmortem Tissue

Poisoning with volatile substances remains exceptional. Authors report the case of a married couple who were found in a car with a butane gas bottle: the woman was dead and her husband alleged it was an unsuccessful suicide pact. A specific research of volatile substances on postmortem samples with headspace gas chromatography–mass spectrometry following a quantitative determination was performed. The n‐butane concentrations detected were composed of 610 μg/L (cardiac blood), 50 μg/kg (brain), 134 μg/kg (lungs), 285 μg/kg (liver), and 4090 μg/kg (heart) and were compatible with the rare lethal concentrations evoked in the literature. The cause of death was determined to be asphyxiation through n‐butane criminal poisoning. Authors recommendation therefore is to take samples immediately and place them in properly sealed containers and hence analyzing the samples as soon as possible after collecting them or storing them under ?30°C (?22°F) if analyses cannot be performed immediately.     

Methyl tert‐Butyl Ether (MTBE) Detected in Abnormally High Concentrations in Postmortem Blood and Urine from Two Persons Found Dead Inside a Car Containing a Gasoline Spill

Two deep frozen persons, a female and a male, were found dead in a car. There had been an explosive fire inside the car which had extinguished itself. On the floor inside the car were large pools of liquid which smelled of gasoline. The autopsy findings and routine toxicological analyses could not explain the cause of death. Carboxyhemoglobin levels in the blood samples were <10%. Analysis with a headspace gas chromatography revealed methyl tert‐butyl ether (MTBE) concentrations of 185 mg/L (female victim) and 115 mg/L (male victim) in peripheral blood. The urine MTBE concentrations were 150 mg/L and 256 mg/L, respectively. MTBE is a synthetic chemical which is added to gasoline as a fuel oxygenate. Gasoline poisoning is likely to be the cause of the death in these two cases, and MTBE can be a suitable marker of gasoline exposure, when other volatile components have vaporized.     

Assessment of the Role Played by N‐propanol Found in Postmortem Blood in the Discrimination Between Antemortem Consumption and Postmortem Formation of Ethanol Using Rats

This study disproves the reliability of n‐propanol as a biomarker to establish whether the ethanol found in postmortem blood is derived from antemortem ingestion or postmortem putrefactive processes. Two groups of rats were given ethanol or normal saline solution, respectively, and sacrificed 1.5 h later. After putrefaction, blood and, in a few cases, urine samples from the rats were analyzed for ethanol and n‐propanol by head‐space gas chromatography equipped with flame ionization detection. Although the concentration ratios of ethanol/n‐propanol in the postmortem blood collected from the bodies without prior alcohol consumption were expected to be <20 (as per limited case reports and previous in vitro studies), in samples from several rats that were on saline solution, this ratio was found to exceed 20. In conclusion, the concentration ratio of ethanol/n‐propanol in postmortem blood does not allow for the discernment between antemortem ingestion and the postmortem synthesis of ethanol.