Search results for "gas chromatography-mass spectrometry"
showing 10 items of 318 documents
Detection of gamma-hydroxybutyrate in hair: Validation of GC–MS and LC–MS/MS methods and application to a real case
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…
Understanding the role of saliva in aroma release from wine by using static and dynamic headspace conditions.
2014
The aim of this work was to determine the role of saliva in wine aroma release by using static and dynamic headspace conditions. In the latter conditions, two different sampling points (t = 0 and t = 10 min) corresponding with oral (25.5 °C) and postoral phases (36 °C) were monitored. Both methodologies were applied to reconstituted dearomatized white and red wines with different nonvolatile wine matrix compositions and a synthetic wine (without matrix effect). All of the wines had the same ethanol concentration and were spiked with a mixture of 45 aroma compounds covering a wide range of physicochemical characteristics at typical wine concentrations. Two types of saliva (human and artifici…
Case report: Another death associated to γ-hydroxybutyric acid intoxication
2019
Abstract We report a fatal γ-hydroxybutyric acid (GHB) intoxication of a forty-year old man. According to an acquaintances’ statement, the deceased had drunk a beverage containing GHB approximately five hours before he was found. Postmortem GHB concentrations were determined using gas chromatography coupled to single quadrupole mass spectrometry after simple protein precipitation with methanol and derivatization with BSTFA (1% TMCS). Concentrations in body fluids and tissues of the deceased were as follows: cardiac blood 384 mg/L, femoral blood 358 mg/L, urine 864 mg/L, brain tissue 211 mg/kg, liver tissue 201 mg/kg, kidney tissue 492 mg/kg, bile 334 mg/L and gastric content 2025 mg/L. In a…
GHB related acids (dihydroxy butyric acids, glycolic acid) can help in the interpretation of post mortem GHB results.
2020
Post mortem gamma hydroxy butyric acid (GHB) concentrations should be interpreted with caution since GHB concentrations can increase after death. Post mortem concentrations after the intake of GHB ante mortem do overlap with concentration ranges in cases without known exposure to GHB and make an interpretation challenging. GHB is known to undergo intensive metabolism to related acids (glycolic acid (GA), succinic acid (SA), 2,4- and 3,4-dihydroxy butyric acid (2,4-OH-BA and 3,4-OH-BA)). GHB and these related acids were analyzed using a validated gas chromatographic mass spectrometric (GC-MS) method after liquid liquid extraction and trimethylsilylation. SA concentrations were not usable pos…
Concentrations of 9-Tetrahydrocannabinol and 11-Nor-9-Carboxytetrahydrocannabinol in Blood and Urine After Passive Exposure to Cannabis Smoke in a C…
2010
Cannabinoid concentrations in blood and urine after passive exposure to cannabis smoke under real-life conditions were investigated in this study. Eight healthy volunteers were exposed to cannabis smoke for 3 h in a well-attended coffee shop in Maastricht, Netherlands. An initial blood and urine sample was taken from each volunteer before exposure. Blood samples were taken 1.5, 3.5, 6, and 14 h after start of initial exposure, and urine samples were taken after 3.5, 6, 14, 36, 60, and 84 h. The samples were subjected to immunoassay screening for cannabinoids and analyzed using gas chromatography-mass spectrometry (GC-MS) for Delta(9)-tetrahydrocannabinol (THC), 11-nor-hydroxy-Delta(9)-tetra…
In vitro production of GHB in blood and serum samples under various storage conditions
2011
Abstract The in vitro production of GHB was observed in freshly collected, untreated whole blood samples using glass BD-Vacutainers and polypropylene S-monovettes. GHB concentrations were determined daily over a period of one week and after 3, 6 and 9 weeks again. Furthermore, the GHB concentration in 40 untreated random whole blood samples stored at 4 °C for a longer period of time (10 samples 12 month, 10 samples 24 month and 20 samples 36 month) was also determined. For comparison, the in vitro production of GHB in freshly collected and prepared serum samples was observed. GHB serum concentrations were determined three times over a period of one week and once again after six weeks. Sampl…
A fatal paramethoxymethamphetamine intoxication.
2003
During the last years in Germany a marked increase in the use of amphetamines such as 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) has been observed. The use of these recreational drugs is especially common among young people participating in rave parties. Occasionally ring-methoxylated phenethylamine derivatives like paramethoxymethamphetamine (PMMA) or paramethoxyamphetamine (PMA) are found in street drugs offered as ecstasy. These compounds exhibit a higher toxicity than the methylenedioxyamphetamine derivatives. We report on the death of a 22-year-old man after the ingestion of ecstasy pills containing PMMA and PMA. The PMMA concentration in femoral blood was 0.85 mg/l. Besides PMA…
Detection of γ‐hydroxybutyric acid‐related acids in blood plasma and urine: Extending the detection window of an exogenous γ‐hydroxybutyric acid inta…
2021
In crimes facilitated by γ-hydroxybutyric acid (GHB) administration, the frequent occurrence of anterograde amnesia of the victims as well as the short detection window and variations of endogenous GHB concentrations complicate obtaining analytical proof of GHB administration. Because elevated endogenous organic acid concentrations have been found in the urine of patients with succinic semialdehyde deficiency (leading to accumulation of GHB in human specimens) and after GHB ingestion, we searched for an alternative way to prove GHB administration via detection of elevated organic acid concentrations in blood plasma and urine. We collected blood and urine samples from narcolepsy patients (n …
Determination of haemoglobin adducts of acrylamide and glycidamide in smoking and non-smoking persons of the general population
2005
Acrylamide (AA) is a food-borne toxicant suspected to be carcinogenic to humans. It is formed in the heating process of starch-containing food. Currently, there is a great discussion about the possible human health risks connected with the dietary uptake of acrylamide. Haemoglobin adducts of acrylamide and its oxidative metabolite glycidamide are both markers of biochemical effect. However, because glycidamide has a higher carcinogenic potency than acrylamide itself, the glycidamide adduct might mirror the genotoxicity better than acrylamide adducts. In order to gain more information about the human metabolism of acrylamide, we investigated a small group of persons for the effective interna…
Biomonitoring of Multiple Mycotoxins in Urine by GC–MS/MS: A Pilot Study on Patients with Esophageal Cancer in Golestan Province, Northeastern Iran
2021
A pilot study to investigate the occurrence of 10 mycotoxins (deoxynivalenol, DON