Paul Van Hee,
Hugo Neels,
Mireille De Doncker,
Nicolas Vrydags,
Katinka Schatteman,
Wim Uyttenbroeck,
Nicole Hamers,
Dirk Himpe,
Willy Lambert
Laboratory of Biochemistry and Toxicology, Ziekenhuis Netwerk Antwerpen Stuivenberg, Antwerp, Belgium.
Analysis of blood of severely intoxicated patients always requires prompt investigation. Diagnosis of intoxication with ethylene glycol, gamma-hydroxybutyric acid or D-lactic acid takes hours, since several different procedures are required. Rapid derivatization of the common hydroxyl function may resolve this analytical problem. Here we describe a fast method for the simultaneous measurement of ethylene glycol, glycolic acid, gamma-hydroxybutyric acid and racemic lactic acid. Only 20 microl of serum, plasma or urine are required for immediate derivatization at 70 degrees C with 750 microl of bis-N,O-trimethylsilyl trifluoroacetamide after adding 20 microl of internal standard solution (1,3-propylene glycol) and 20 microl of the catalyst dimethylformamide. After centrifugation an aliquot is transferred to a gas chromatographic system and analyzed with electron-impact mass spectrometry in selective ion monitoring mode. The derivatized acids and ethylene glycol are well separated and detected with a limit of detection ranging from 0.12 mg/l for ethylene glycol to 0.95 mg/l for gamma-hydroxybutyric acid, while the limit of quantification ranged from 0.4 mg/l for ethylene glycol to 3.15 mg/l for gamma-hydroxybutyric acid. The method is linear from 0.5 to 1800 mg/l blood for ethylene glycol, from 0.7 to 1200 mg/l for lactic acid, from 1.2 to 1800 mg/l for glycolic acid, and from 3.2 to 200 mg/l for gamma-hydroxybutyric acid, with analytical recoveries, accuracy, day-to-day and within-day precision well within the required limits. Total analysis time with one calibrator was 30 min, derivatization time included. This method is very suitable for emergency toxicology, since several toxic substances can be quantified simultaneously in a fast and sensitive manner.
Mesh-terms: Chromatography; Ethylene Glycol :: analysis; Glycolates :: analysis; Glycols :: chemistry; Humans; Hydroxybutyrates :: analysis; Ions; Kinetics; Lactic Acid :: analysis; Mass Fragmentography :: methods; Sensitivity and Specificity; Spectrum Analysis, Mass :: methods; Time Factors; Trimethylsilyl Compounds :: chemistry;
Other papers by authors:
Laboratorium voor Toxicologie, ZNA Stuivenberg, Lange Beeldekensstraat 267, B-2060 Antwerpen, Belgium.
Isabela Tarcomnicu,
Alexander L N van Nuijs,
Katrien Aerts,
Mireille De Doncker,
Adrian Covaci,
Hugo Neels
Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium.
Ethyl glucuronide (EtG) detection in non-conventional matrices, such as hair and meconium, can provide useful information on alcohol abuse over a long time frame, for example during pregnancy or after a withdrawal treatment. This study reports on the development, validation and application of a new hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for the analysis of EtG in meconium and hair. For each matrix, the sample preparation and the chromatographic separation were thoroughly optimised. Additionally, experiments with reversed-phase liquid chromatography were also performed in the development stages. Analyses were carried out using a Phenomenex Luna HILIC column (150mmx3mm, 5mum) and a mobile phase composed by ammonium acetate 2mM and acetonitrile, in gradient. Different SPE cartridges (Oasis MAX, Oasis WAX, aminopropyl silica) and solvents were tested in order to obtain the highest recoveries and cleanest extracts. Optimal results were obtained for meconium with aminopropyl cartridges, while for hair an incubation of 16h with 2mL of water and acetonitrile (50/50, v/v) provided good results. The analytical method was validated for both matrices (meconium and hair) by assessing linearity, precision, accuracy, recovery and limit of quantification. The calibration curve concentrations ranged from 50 to 1200pg/mg for meconium and from 20 to 1000pg/mg for hair. Real meconium and hair samples were analyzed and results were consistent with literature.
Paediatric Intensive Care Unit ZNA Queen Paola Children's Hospital Antwerp, Belgium.
Background: Chloral hydrate is used worldwide as a first-line agent for procedural sedation in paediatric patients undergoing painless diagnostic investigations. Chloral hydrate overdoses in children and adults have been reported to cause various toxicities, including central nervous system, respiratory and cardiac depression with sometimes fatal outcome. Patient and methods: A 3-month old girl was admitted after an unintentional administration of a 10-fold dose of chloralhydrate (667 mg/kg). She showed respiratory insufficiency in need of intubation and ventilation. Gastric endoscopy revealed esophagitis and gastric ulcerations. To assess the need for haemodialysis, serum trichloroethanol (TCE) was determined using a mass spectrometric quantification after a methyl tertiary butyl ether extraction using an external standard method. The serum TCE level 6 hours after administration was 89 mg/L and declined to 20 mg/L within 24 hours. The child could be extubated the next day, her further course was uneventful. Conclusion: The repeated determination of serum TCE levels prevented a technically difficult and risky haemodialysis in this very young patient.
Maes Clinics, Belgium.
BACKGROUND: Major depression is characterized by a decreased antioxidant status, an induction of the inflammatory and oxidative and nitrosative (IO&NS) pathways and inflammatory-neurodegenerative (I&ND) pathways. This study examines two markers of oxidative stress in depression, i.e. plasma peroxides and serum oxidized LDL (oxLDL) antibodies. METHODS: Blood was sampled in 54 patients with major depression (mean+/-SD age=43.5+/-11.6years) and 37 normal volunteers (43.6+/-11.1years). The severity of illness was measured by means of the Hamilton Depression Rating Scale. The Fibromyalgia and Chronic Fatigue Syndrome Rating Scale was used to measure severity of "psychosomatic" symptoms in depression. RESULTS: We found significantly higher plasma peroxides (p=0.002) and serum oxLDL antibodies (p=0.0002) in depressed patients as compared to normal controls. There was no significant correlation between both markers and both independently from each other predicted major depression. There were significant correlations between the oxLDL antibodies and the scores on two items of the FF scale, i.e. gastro-intestinal symptoms and headache. DISCUSSION: The results show that major depression is accompanied by increased oxidative stress and lipid peroxidation. These results further extend the IO&NS pathophysiology of major depression. Since increased peroxides and oxLDL antibodies are predictors of coronary artery disease (CAD) and neurodegeneration, our findings suggest that IO&NS pathways are involved in the increased incidence of both CAD and neurodegeneration in depression.
Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Wilrijk, Belgium.
BACKGROUND: Hexabromocyclododecane (HBCD) is a high-production-volume chemical used as flame retardant in polystyrene insulation and textiles. Because it is not chemically bound to the polymer, HBCD can migrate into the environment, contaminating indoor dust and foodstuff. OBJECTIVES: We examined for the first time the relationship between combined exposure to three HBCD isomers ( summation operatorHBCDs) via ingestion of food (duplicate diets) and indoor dust and HBCD concentrations in serum for 16 Belgian adults (20-25 years of age). We also determined the chiral signatures of HBCDs to advance understanding of source-to-human enantioselective degradation and/or metabolism. METHODS: Concentrations and chiral signatures of alpha-, beta-, and gamma-HBCD in duplicate diets, dust, and serum were measured by liquid chromatography/tandem mass spectrometry. RESULTS: Dietary intakes of summation operatorHBCDs were 1.2-20 ng/day (average, 7.2 ng/day), whereas those estimated under average (20 mg dust/day) and high (50 mg dust/day) dust ingestion scenarios were 1.1-15 ng/day (average intake, 3.2 ng/day) and 2.8-38 ng/day (average intake, 8.0 ng/day), respectively. Concentrations of summation operatorHBCDs measured in blood serum were < 0.5 to 11 ng/g lipid weight (lw)(average, 2.9 ng/g lw). gamma-HBCD dominated in food, whereas alpha-HBCD dominated in dust and was the sole isomer in serum. Although exposure via dust ingestion correlated significantly (p < 0.01) with concentrations in serum, no such correlation was evident with dietary exposure (p > 0.1). Although no enantioselective enrichment was detected in either dust or diet, substantial enrichment of (-)alpha-HBCD was observed in serum. CONCLUSIONS: Serum concentrations of HBCDs were correlated with the exposure via dust, but not via dietary ingestion. The enrichment of the (-)alpha-HBCD enantiomer in humans appears to be due to in vivo enantioselective metabolism/excretion rather than ingestion of dust or diet.
Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Laboratory of Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.
Harbour porpoises are one of the three cetacean species inhabiting the Black Sea. This is the first study to report on polybrominated diphenyl ethers (PBDEs) and naturally-produced compounds, methoxylated PBDEs (MeO-PBDEs) and polybrominated hexahydroxanthene derivatives (PBHDs), in tissues (kidney, brain, blubber, liver, muscle) of male harbour porpoises (11 adults, 9 juveniles) from the Black Sea. Lipid-normalized concentrations decreased from muscle>blubber>liver>kidney>brain for the sum of polychlorinated biphenyls (PCBs) and for the sum of PBDEs. Among the naturally-produced compounds, levels of PBHDs were higher than of MeO-PBDEs, with tri-BHD and 6-MeO-BDE 47 being the dominant compounds for both groups, respectively. Concentrations of naturally-produced compounds decreased from blubber to brain, similarly to the sum of DDT and metabolites (DDXs). Concentrations of DDXs were highest, followed by PCBs, HCB, PBHDs, PBDEs and MeO-PBDEs. Levels of PCBs and PBDEs in blubber were lower than concentrations reported for harbour porpoises from the North Sea, while concentrations of DDXs were higher.
Maes Clinics, Antwerp, Belgium. crc.mh@telenet.be.
Myalgic encephalomyelitis / chronic fatigue syndrome (ME/CFS) is a medical illness characterized by disorders in inflammatory and oxidative and nitrosative (IO&NS) pathways.This paper examines the role of Coenzyme Q10 (CoQ10), a mitochondrial nutrient which acts as an essential cofactor for the production of ATP in mitochondria and which displays significant antioxidant activities.Plasma CoQ10 has been assayed in 58 patients with ME/CFS and in 22 normal controls; the relationships between CoQ10 and the severity of ME/CFS as measured by means of the FibroFatigue (FF) scale were measured. Plasma CoQ10 was significantly (p=0.00001) lower in ME/CFS patients than in normal controls. Up to 44.8% of patients with ME/CFS had values beneath the lowest plasma CoQ10 value detected in the normal controls, i.e. 490 mug/L. In ME/CFS, there were significant and inverse relationships between CoQ10 and the total score on the FF scale, fatigue and autonomic symptoms. Patients with very low CoQ10 (<390 mug/L) suffered significantly more from concentration and memory disturbances. The results show that lowered levels of CoQ10 play a role in the pathophysiology of ME/CFS and that symptoms, such as fatigue, and autonomic and neurocognitive symptoms may be caused by CoQ10 depletion. Our results suggest that patients with ME/CFS would benefit from CoQ10 supplementation in order to normalize the low CoQ10 syndrome and the IO&NS disorders. The findings that lower CoQ10 is an independent predictor of chronic heart failure (CHF) and mortality due to CHF may explain previous reports that the mean age of ME/CFS patients dying from CHF is 25 years younger than the age of those dying from CHF in the general population. Since statins significantly decrease plasma CoQ10, ME/CFS should be regarded as a relative contraindication for treatment with statins without CoQ10 supplementation.
Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Belgium.
The development and validation of an analytical method is presented for the determination of bisphenol-A (BPA) and triclosan (TCS), two ubiquitous contaminants, in serum and urine. The glucuronidated metabolites were first turned into their free forms to determine total BPA and TCS. The determination consisted of a solid-phase extraction on Oasis HLB cartridges followed by an extractive derivatization with pentafluorobenzoylchloride. The extract was then purified on 10%(w/w) acidified silica and analyzed by gas chromatography-mass spectrometry in electron-capture negative ionization mode. Monitored ions were m/z 616 and 406 for BPA and m/z 482 and 287 for TCS, respectively. Limits of quantification were 0.5ng/mL in serum and 0.2ng/mL in urine for BPA and 0.1ng/mL in serum and 0.05ng/mL in urine for TCS. Method recoveries were between 76 and 110%, while repeatability was below 20%. The method was applied on 20 serum and 20 urine samples. The detection frequency in serum was 10% and 55% for BPA and TCS, respectively. BPA and TCS could be detected in all urine samples with median concentrations of 1.25ng BPA/mL (range 0.58-5.20ng/mL) and 1.71ng TCS/mL (0.18-672ng/mL).
Paulo R Dorneles,
José Lailson-Brito,
Alin C Dirtu,
Liesbeth Weijs,
Alexandre F Azevedo,
João P M Torres,
Olaf Malm,
Hugo Neels,
Ronny Blust,
Krishna Das,
Adrian Covaci
Biophysics Institute, Rio de Janeiro Federal University (UFRJ), Rio de Janeiro, Brazil; Aquatic Mammal and Bioindicator Laboratory (MAQUA), School of Oceanography, Rio de Janeiro State University (UERJ), Brazil.
Liver samples from 51 cetaceans, comprising 10 species, stranded between 1994 and 2006 in a highly industrialized and urbanized region in Southeast Brazil, were analyzed for polybrominated diphenyl ethers (PBDEs) and methoxylated-PBDEs (MeO-PBDEs). A concentration range of PBDEs (3-5960ng/g lw) similar to that observed in Northern Hemisphere dolphins was found. MeO-PBDE concentrations in continental shelf (CS) dolphins from Brazil are among the highest detected to date in cetaceans (up to 250microg/g lw). Higher SigmaMeO-PBDE concentrations were measured in CS and oceanic dolphins than in estuarine dolphins. The SigmaPBDE/SigmaMeO-PBDE ratio varied significantly ranging from a mean value of 7.12 to 0.08 and 0.01 for estuarine, CS and oceanic species, respectively. A positive correlation was observed between SigmaPBDE and year of stranding of male estuarine dolphins (Sotalia guianensis), which suggests temporal variation in the exposure. Placental transfer of organobrominated compounds was also evidenced in S. guianensis.
Latest similar papers:
Laboratoire de Génie des Procédés et Matériaux (LGPM), Ecole Centrale Paris, Grande voie des vignes, 92295 chatenay-Malabry, PressUniverSud, France; Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Université Paris XII, Créteil, France.
Within the context of the future space missions to Mars (MSL 2011 and Exomars 2016), which aim at searching for traces of life at the surface, the detection and quantitation of enantiomeric organic molecules is of major importance. In this work, we have developed and optimized a method to derivatize and analyze chiral organic molecules suitable for space experiments, using N,N-dimethylformamide dimethylacetal (DMF-DMA) as the derivatization agent. The temperature, duration of the derivatization reaction, and chromatographic separation parameters have been optimized to meet instrument design constraints imposed upon space experiment devices. This work demonstrates that, in addition to its intrinsic qualities, such as production of light-weight derivatives and a great resistance to drastic operating conditions, DMF-DMA facilitates simple and fast derivatization of organic compounds (three minutes at 140 degrees C in a single-step) that is suitable for an in situ analysis in space. By using DMF-DMA as the derivatization agent, we have successfully identified 19 of the 20 proteinic amino acids and been able to enantiomerically separate ten of the potential 19 (glycine being non-chiral). Additionally, we have minimized the percentage of racemized amino acid compounds produced by optimizing the conditions of the derivatization reaction itself. Quantitative linearity studies and the determination of the limit of detection show that the proposed method is also suitable for the quantitative determination of both enantiomeric forms of most of the tested amino acids, as limits of detection obtained are lower than the ppb level of organic molecules already detected in Martian meteorites.
Department of Pathology and Laboratory Medicine, Albany Medical Center, Albany, New York, USA.
Ethylene glycol (EG), a relatively infrequent cause of fatal intoxication, presents an analytical challenge for forensic confirmation in postmortem toxicology. We report EG and glycolic acid (GA) quantification in postmortem blood by gas chromatography coupled with ion trap mass spectrometry (GC-MS) analysis using a modification of a previously reported clinical method. The method is linear from 50 to 4000 mg/L with a limit of detection of 25 mg/L for both EG and GA. Interassay coefficient of variation (2.1-8.6%, 4.3-6.0%) and accuracy (96-101%, 92-105%) were determined for EG and GA, respectively. EG concentration by ion trap GC-MS correlated closely (R(2)= 0.995) with EG quantified by GC-flame-ionization detection. Analysis of blood from 20 autopsies with no evidence of EG exposure did not reveal detectable EG or GA. In 12 medical examiner cases with EG poisoning as cause of death, EG concentrations ranged widely from 58 to 7790 mg/L with a mean of 1830 mg/L, and the GA concentration averaged 1360 mg/L with a narrower range of 810-1770 mg/L. EG and GA levels correlate poorly (R(2)= 0.15) in postmortem blood with discordantly low EG concentrations in two cases. Birefringent oxylate crystals in renal tissue was a consistent finding. In conclusion, a sensitive and specific GC-MS method for detection and quantification of EG and GA has been validated and a study of fatal EG poisonings revealed forensic application of the method.
Forensic Medicine and Science, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom. Huda.Hassan@formed.gla.ac.uk
Beta-hydroxybutyrate (BHB) is considered a potential biomarker for alcoholic ketoacidosis (AKA). A robust and sensitive method was developed and validated for the quantitative determination of BHB in postmortem blood and urine using deuterated gamma-hydroxybutyrate as an internal standard. Samples were analyzed by gas chromatography-mass spectrometry following liquid-liquid extraction and silyl derivatization. The limits of detection and lower limits of quantification in blood and urine were 2 and 7 mg/L and 2 and 6 mg/L, respectively. The interday and intraday precision was measured by coefficients of variation for blood and urine and ranged from 1.0 to 12.4% for quality control samples spiked at 50 and 300 mg/L. The linear range of 50-500 mg/L resulted in an average correlation of R(2)> 0.99, and the average extraction recoveries in blood and urine were >or= 82% and >or= 59%, respectively. BHB remains stable in blood spiked at a concentration of 300 mg/L for 15 days when stored within a refrigerator (2-5 degrees C). Postmortem blood and urine samples were analyzed using the validated method for cases where the deceased had a history of chronic alcohol abuse to establish the use of BHB as a potential marker of AKA.
PKU Green Chemistry Center, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (PR China), Fax:(+86) 10-62751708.
Analytical Research and Development, US Pharmacopeial Convention, Rockville, MD 20852-1790, USA.
This paper describes a capillary gas chromatographic method with flame ionization detection for the identification/quantification of ethylene glycol (EG) and diethylene glycol (DEG) in glycerin. The validation study shows that the proposed method is specific, sensitive, precise, and accurate. The linear range of the method was 0.013-0.031mg/mL for EG and 0.012-0.030mg/mL for DEG. Wider ranges may be achievable but were not investigated. The limit of detection of EG and DEG were determined as 0.0018% and 0.0036%(w/w) respectively, and at this concentration the signal-to-noise ratios for EG and DEG were approximately 3:1. The method was also used to determine EG and DEG in toothpaste. The results were compared to those obtained by thin-layer chromatography (TLC) and showed greater sensitivity and specificity.
AP-HP CIB GHU Sud Henri Mondor, Faculté de Médecine, 8 rue du Général Sarrail, 94010 Créteil, France; Inserm U955 Eq07, CHU Henri Mondor, Faculté de Médecine, 8 rue du Général Sarrail, 94010 Créteil, France.
OBJECTIVES: Preparation of reusable and easy to handle Celite(R) chromatographic columns. DESIGN AND METHODS: Weighting precise Celite(R) quantities in cartridges and introducing ethylene glycol methanol solutions. The chromatographic solvents pass throughout Celite(R) under negative pressure. RESULTS: These new minicolumns are reusable. The steroid recoveries' coefficients of variation are less than 10%, and the steroid separation is good. CONCLUSIONS: The reusable Celite(R) cartridge use before steroid immunoassays is easier and less time-consuming than classical glass Celite(R) minicolumns.
Department of Pathology and Laboratory Medicine, Children's Mercy Hospital, Kansas City, MO, USA. ugarg@cmh.edu
A unique case of an intentional overdose of ethylene glycol resulting in a fatality is described. The decedent had a very high concentration of ethylene glycol without elevated concentrations of its metabolites or crystalluria. The ethylene glycol concentrations in blood, urine, and vitreous fluid were 2340, 2261, and 1028 mg/dL, respectively. Osmolality of blood and vitreous fluid was also very high at 1426 and 534 mOsm/kg, respectively. No crystals were found in the urine. Furthermore, on the urine organic acids profile the ethylene glycol metabolites oxalic, glycolic, and glyoxylic acids were within the reference ranges. In addition to ethylene glycol, the decedent had an elevated level of mirtazapine, an antidepressant, and a low level of bupropion. It was estimated that the subject consumed 1034 g of ethylene glycol. To our knowledge, this is the first case of death from severe ethylene glycol poisoning in the absence of ethylene glycol metabolites or crystalluria.
Department of Critical Care Medicine, University Hospital of Antwerp, Edegem, Belgium.
Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139.
The accurate quantification of nucleic acids is of utmost importance for clinical diagnostics, drug discovery, and basic science research. These applications require the concurrent measurement of multiple targets while demanding high-throughput analysis, high sensitivity, specificity between closely related targets, and a wide dynamic range. In attempt to create a technology that can simultaneously meet these demands, we recently developed a method of multiplexed analysis using encoded hydrogel particles. Here, we demonstrate tuning of hydrogel porosity with semi-interpenetrating networks of poly(ethylene glycol), develop a quantitative model to understand hybridization kinetics, and use the findings from these studies to enhance particle design for nucleic acid detection. With an optimized particle design and efficient fluorescent labeling scheme, we demonstrate subattomole sensitivity and single-nucleotide specificity for small RNA targets.
Laboratoire de Recherche et Développement Analytique, Centre Technique de la Conservation des Produits Agricoles, 41 avenue Paul Claudel, 80480, Dury les Amiens, France, cedric.przybylski@univ-evry.fr.
The carbamates are a well-known thermosensible pesticides class, which are highly prone to degradation via fragmentation and/or rearrangement mechanisms leading to a difficult direct gas chromatography (GC) analysis, i.e., without derivatization. In this paper, spermine and thiabendazole both at 1 mg/mL were highlighted as efficient analyte protectants to improve the direct and simultaneous analysis of 16 carbamates both in solvent and green vegetable matrices. These two molecules were compared in mixture or in combination with three well-known efficient analyte protectants 3-ethoxy-1,2-propanediol, D:-sorbitol, and L:-gulonic acid-gamma-lactone. The potential benefits were investigated in GC hyphenated to mass spectrometry (GC-MS) with two injection modes: programmable temperature vaporizing injector in a solvent split mode (PTV-SSI) and on-column injection (OCI). It was shown that the combined effect of the five protective agents led to the best sensitivity improvement with limits of detection between 0.1-0.4 and 0.03-0.1 mug/kg and limits of quantification between 0.3-1.1 and 0.1-0.5 mug/kg for PTV-SSI and OCI mode, respectively. The correlation coefficients from the analyzed 1-500 mug/kg range were all >0.999 both in the solvent and matrices studied. The recoveries of carbamates from three spiked matrices over five replicates at 20 and 100 microg/kg were in the range 90-107% with relative standard deviation (RSD) equal to 2-7% for PTV-SSI and 92-107% with an RSD equal to 1-6% for OCI. The use of spermine and thiabendazole with other analyte protectants shows very efficient partial or total reduction of breakdown of the most sensitive carbamates such as the N-sulfenylated ones.
