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Namera A, Uekusa K, Saito T, Yoshimoto K, Ishiuchi N, Murata K, Nagao M. A method for determining valproic acid in human whole blood and urine via gas chromatography-mass spectrometry and small-scale inter-laboratory trial. Leg Med (Tokyo) 2022; 59:102133. [PMID: 35998544 DOI: 10.1016/j.legalmed.2022.102133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 08/01/2022] [Accepted: 08/12/2022] [Indexed: 10/31/2022]
Abstract
A simple and cost-effective method for analyzing valproic acid (VPA) in biological samples was developed. VPA was extracted in methyl tertiary-butyl ether (MTBE) and derivatized using trimethylsilyldiazomethane. The MTBE extract was analyzed by gas chromatography-mass spectrometry (GC-MS). The extraction recovery in human whole blood and urine was over 90 %, with good linearity in the range of 1.0 to 250 µg/mL of VPA. The RSD for 2.0, 20, and 200 μg/mL VPA in whole blood ranged from 0.9 to 4.7 % for intra-day and 1.5 to 5.9 % for inter-day. The RSD for 2.0, 20, and 200 μg/mL VPA in urine ranged from 1.9 to 2.6 % for intra-day and 1.2 to 2.9 % for inter-day. As a preliminary cross-validation study, a cross-check was conducted using blinded concentration samples. The results demonstrated that the assay data of the two laboratories were comparable.
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Affiliation(s)
- Akira Namera
- Department of Forensic Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan.
| | - Kyoko Uekusa
- Department of Legal Medicine, Nippon Medical School, Japan
| | - Takeshi Saito
- Department of Emergency and Critical Care Medicine, Tokai University School of Medicine, Japan
| | - Kanji Yoshimoto
- Department of Food Sciences and Biotechnology, Graduate School of Science and Technology, Hiroshima Institute of Technology, Japan
| | - Naoki Ishiuchi
- Center for Cause of Death Investigation Research, Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan
| | - Kazuhiro Murata
- Department of Forensic Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan
| | - Masataka Nagao
- Department of Forensic Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Japan
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Wu X, Gu M, Wang W, Zhang H, Tang Z. Case Report: Early Recognition, Treatment, and Occupational Safety Protection are Crucial for Methanol Toxicity. Front Med (Lausanne) 2022; 9:918812. [PMID: 35774994 PMCID: PMC9237385 DOI: 10.3389/fmed.2022.918812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/24/2022] [Indexed: 11/16/2022] Open
Abstract
Background Despite significant progress in treating methanol poisoning, the lack of training, hazard communication, and occupational safety protection education contributes to the risk of occupational exposure and methanol toxicity. In addition, early diagnosis and timely medical care are essential to reduce the risk of morbidity and mortality, yet it remains a challenging procedure. Case Report A 35-year-old man working in a fireworks factory came to our emergency department with acute mental change and progressive disturbance of consciousness. The patient's vital signs were stable, and he presented with enlargement of both pupils with a weak reaction to light. Head computed tomography showed low signal intensities in the bilateral basal ganglia. He was admitted to the neurologic intensive care unit, where additional laboratory workup showed high anion-gap metabolic acidosis. Methanol poisoning was thus considered. Before being treated with sodium bicarbonate infusion, hemodialysis, folate, and high-dose vitamin B, the blood and urine samples were collected for toxicity tests, which turned out to be methanol poisoning. After 8 hours of hemodialysis, the patient's consciousness recovered, but he complained of a complete loss of vision in both eyes. Brain and optic nerve magnetic resonance images showed bilateral symmetric putamen lesions and optic neuropathy. Ophthalmic tests indicated visual pathway impairment and optic disc swelling but no fluorescein leakage. The right eye's vision was partially restored on the third day, but he could only count fingers at 20 cm. Unfortunately, his eyesight ceased to improve during the 6 months of follow-up. Conclusions Early diagnosis and prompt treatment will improve the prognosis of methanol poisoning in terms of vision and patient survival. Awareness and supervision of commercial alcohol use are indispensable for similar industrial processes.
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Affiliation(s)
- Xiaomei Wu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Meifeng Gu
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Wei Wang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Hainan Zhang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Zhenchu Tang
- Department of Neurology, The Second Xiangya Hospital, Central South University, Changsha, China
- Hunan Key Laboratory of Tumor Models and Individualized Medicine, The Second Xiangya Hospital, Central South University, Changsha, China
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Houzé P, Labat L. Apport de l’électrophorèse capillaire de zone dans l’exploration étiologique des acidoses métaboliques. TOXICOLOGIE ANALYTIQUE ET CLINIQUE 2021. [DOI: 10.1016/j.toxac.2021.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Pedersen DS, Bélanger P, Frykman M, Andreasen K, Goudreault D, Pedersen H, Hindersson P, Breindahl T. Ethylene glycol: Evidence of glucuronidation in vivoshown by analysis of clinical toxicology samples. Drug Test Anal 2019; 11:1094-1108. [PMID: 30845374 PMCID: PMC6767423 DOI: 10.1002/dta.2584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 02/28/2019] [Accepted: 02/28/2019] [Indexed: 11/06/2022]
Abstract
In the search for improved laboratory methods for the diagnosis of ethylene glycol poisoning, the in vivo formation of a glucuronide metabolite of ethylene glycol was hypothesized. Chemically pure standards of the β‐O‐glucuronide of ethylene glycol (EG‐GLUC) and a deuterated analog (d4‐EG‐GLUC) were synthesized. A high‐performance liquid chromatography and tandem mass spectrometry method for determination of EG‐GLUC in serum after ultrafiltration was validated. Inter‐assay precision (%RSD) was 3.9% to 15.1% and inter‐assay %bias was −2.8% to 12.2%. The measuring range was 2–100 μmol/L (0.48–24 mg/L). Specificity testing showed no endogenous amounts in routine clinical samples (n = 40). The method was used to analyze authentic, clinical serum samples (n = 31) from patients intoxicated with ethylene glycol. EG‐GLUC was quantified in 15 of these samples, with a mean concentration of 6.5 μmol/L (1.6 mg/L), ranging from 2.3 to 15.6 μmol/L (0.55 to 3.7 mg/L). In five samples, EG‐GLUC was detected below the limit of quantification (2 μmol/L) and it was below the limit of detection in 11 samples (1 μmol/L). Compared to the millimolar concentrations of ethylene glycol present in blood after intoxications and potentially available for conjugation, the concentrations of EG‐GLUC found in clinical serum samples are very low, but comparable to concentrations of ethyl glucuronide after medium dose ethanol intake. In theory, EG‐GLUC has a potential value as a biomarker for ethylene glycol intake, but the pharmacokinetic properties, in vivo/vitro stability and the biosynthetic pathways of EG‐GLUC must be further studied in a larger number of patients and other biological matrices.
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Affiliation(s)
- Daniel Sejer Pedersen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Patrick Bélanger
- Centre de Toxicologie du Québec (CTQ)Institut National de Santé Publique du Québec (INSPQ), Québec Québec Canada
| | - Mikael Frykman
- Department of Drug Design and Pharmacology, Faculty of Health and Medical SciencesUniversity of Copenhagen Copenhagen Denmark
| | - Kirsten Andreasen
- Department of Clinical BiochemistryNorth Denmark Regional Hospital Hjørring Denmark
| | - Danielle Goudreault
- Laboratory of Specialized Biochemistry, Department of Clinical BiochemistryOptilab Montréal CHUM, building CHU Ste‐Justine, Montréal Quebec Canada
| | | | - Peter Hindersson
- Department of Clinical BiochemistryNorth Denmark Regional Hospital Hjørring Denmark
| | - Torben Breindahl
- Department of Clinical BiochemistryNorth Denmark Regional Hospital Hjørring Denmark
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Affiliation(s)
- Jeffrey A Kraut
- From Medical and Research Services and Division of Nephrology, Veterans Health Administration Greater Los Angeles (VHAGLA) Healthcare System, and Membrane Biology Laboratory, David Geffen School of Medicine, University of California, Los Angeles - both in Los Angeles (J.A.K.); and the Division of Emergency Medicine, Washington University School of Medicine, St. Louis (M.E.M.)
| | - Michael E Mullins
- From Medical and Research Services and Division of Nephrology, Veterans Health Administration Greater Los Angeles (VHAGLA) Healthcare System, and Membrane Biology Laboratory, David Geffen School of Medicine, University of California, Los Angeles - both in Los Angeles (J.A.K.); and the Division of Emergency Medicine, Washington University School of Medicine, St. Louis (M.E.M.)
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Hložek T, Bursová M, Čabala R. Simultaneous and cost-effective determination of ethylene glycol and glycolic acid in human serum and urine for emergency toxicology by GC-MS. Clin Biochem 2014; 48:189-91. [PMID: 25500419 DOI: 10.1016/j.clinbiochem.2014.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/28/2014] [Accepted: 12/01/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES A simple, cost-effective, and fast gas chromatography method with mass spectrometry detection (GC-MS) for simultaneous measurement of ethylene glycol, 1,2-propylene glycol and glycolic acid was developed and validated for clinical toxicology purposes. DESIGN AND METHODS Successful derivatization of glycolic acid with isobutyl chloroformate was achieved directly in serum/urine while glycols are simultaneously derivatized by phenylboronic acid. The entire sample preparation procedure is completed within 10 min. RESULTS The assay was proved to be quadratic in the range of 50 to 5000 mgL(-1) with adequate accuracy (96.3-105.8%) and precision (CV ≤ 8.9%). CONCLUSION The method was successfully applied to quantify the selected compounds in serum of patients from emergency units and the results correlated well with parallel GC-FID measurements (R(2) 0.9933 for ethylene glycol and 0.9943 for glycolic acid).
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Affiliation(s)
- Tomáš Hložek
- Institute of Forensic Medicine and Toxicology, First Faculty of Medicine, Charles University in Prague and General University Hospital, 121 08 Prague 2, Czech Republic.
| | - Miroslava Bursová
- Institute of Forensic Medicine and Toxicology, First Faculty of Medicine, Charles University in Prague and General University Hospital, 121 08 Prague 2, Czech Republic; Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 6, 128 43 Prague 2, Czech Republic
| | - Radomír Čabala
- Institute of Forensic Medicine and Toxicology, First Faculty of Medicine, Charles University in Prague and General University Hospital, 121 08 Prague 2, Czech Republic; Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 6, 128 43 Prague 2, Czech Republic
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7
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Fast determination of ethylene glycol, 1,2-propylene glycol and glycolic acid in blood serum and urine for emergency and clinical toxicology by GC-FID. Talanta 2014; 130:470-4. [DOI: 10.1016/j.talanta.2014.07.020] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/02/2014] [Accepted: 07/07/2014] [Indexed: 11/17/2022]
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8
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Heytens L, Neels H, Van Regenmortel N, van den Brink W, Henckes M, Schouwers S, Dockx G, Crunelle CL. Near-fatal persistent anion- and osmolal-gap acidosis due to massive gamma-butyrolactone/ethanol intoxication. Ann Clin Biochem 2014; 52:283-7. [PMID: 25205856 DOI: 10.1177/0004563214553278] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We report a case of an ethanol and massive gamma-butyrolactone (GBL) intoxication, the precursor of the recreational drug gamma-hydroxybutyric acid (GHB), resulting in life-threatening metabolic acidosis (pH 6.5) with a highly increased anion- and osmolal gap. Rapid analysis using gas chromatography revealed a GHB plasma concentration of 4400 mg/L, far above the upper limit concentration of 1000 mg/L found in adult fatalities attributed to GBL. Full recovery was established following supportive treatment including haemodialysis. This is the first report of a combined ethanol/GBL intoxication as a cause of high serum anion- and osmolal-gap metabolic acidosis.
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Affiliation(s)
- Luc Heytens
- Department of Intensive Care, Sint-Augustinus Hospital, Wilrijk, Belgium
| | - Hugo Neels
- Toxicological Center, University of Antwerp, Antwerp, Belgium Laboratory for Clinical Chemistry and Toxicology, ZNA Stuivenberg, Antwerp, Belgium
| | | | - Wim van den Brink
- Amsterdam Institute for Addiction Research, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Manu Henckes
- Department of Nephrology, Sint-Augustinus Hospital, Wilrijk, Belgium
| | - Sofie Schouwers
- Clinical Laboratory, Sint-Augustinus Hospital, Wilrijk, Belgium
| | - Greet Dockx
- Laboratory for Clinical Chemistry and Toxicology, ZNA Stuivenberg, Antwerp, Belgium
| | - Cleo L Crunelle
- Toxicological Center, University of Antwerp, Antwerp, Belgium
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XXXIV International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 27–30 May 2014, Brussels, Belgium. Clin Toxicol (Phila) 2014. [DOI: 10.3109/15563650.2014.906213] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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10
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Presence of appreciable amounts of ethylene glycol, propylene glycol, and diethylene glycol in human urine of healthy subjects. Forensic Toxicol 2013. [DOI: 10.1007/s11419-013-0206-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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11
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Determination of gamma-hydroxybutyric acid in biofluids using a one-step procedure with “in-vial” derivatization and headspace-trap gas chromatography–mass spectrometry. J Chromatogr A 2013; 1296:84-92. [DOI: 10.1016/j.chroma.2013.04.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/09/2013] [Accepted: 04/11/2013] [Indexed: 01/15/2023]
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12
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Wurita A, Suzuki O, Hasegawa K, Gonmori K, Minakata K, Yamagishi I, Nozawa H, Watanabe K. Sensitive determination of ethylene glycol, propylene glycol and diethylene glycol in human whole blood by isotope dilution gas chromatography–mass spectrometry, and the presence of appreciable amounts of the glycols in blood of healthy subjects. Forensic Toxicol 2013. [DOI: 10.1007/s11419-013-0188-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Ethylene glycol poisoning: Quintessential clinical toxicology; analytical conundrum. Clin Chim Acta 2013; 415:107-8. [DOI: 10.1016/j.cca.2012.10.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 10/01/2012] [Accepted: 10/01/2012] [Indexed: 11/23/2022]
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14
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Grenier V, Huppé G, Lamarche M, Mireault P. Enzymatic assay for GHB determination in forensic matrices. J Anal Toxicol 2012; 36:523-8. [PMID: 22722059 DOI: 10.1093/jat/bks053] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Current procedures for the determination of gamma-hydroxybutyric acid (GHB) require time-consuming extraction and derivatization steps before chromatographic detection, making a high-throughput alternative desirable. Bühlmann Laboratories offers an enzymatic assay for the quantitative determination of GHB in urine and serum. We report the adaptation of this photometric assay to the Thermo Scientific MGC-240 analyzer and its use in the determination of GHB in forensic matrices including urine, whole blood and vitreous humour. Most matrices require only a brief centrifugation before analysis, while blood requires an additional protein precipitation step. A variety of cases (sexual assaults, impaired drivers and death investigations) have been analyzed alongside the gas chromatography-mass spectrometry (GC-MS) reference method. Correlation with the GC-MS has been found to be acceptable, with no false negatives and few false positives, although postmortem samples appear more prone to testing false positive than do antemortem samples. Simple sample preparation and high throughput allow for a significant reduction in analysis time relative to chromatographic methods. This assay is used as a screening method in our laboratory, with a quantitative GC-MS method serving for the confirmation of positive results. To our knowledge, this represents the first evaluation of an enzymatic assay for GHB in a forensic context.
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Porter WH. Ethylene glycol poisoning: quintessential clinical toxicology; analytical conundrum. Clin Chim Acta 2011; 413:365-77. [PMID: 22085425 DOI: 10.1016/j.cca.2011.10.034] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 10/21/2011] [Accepted: 10/25/2011] [Indexed: 12/20/2022]
Abstract
Ethylene glycol poisoning is a medical emergency that presents challenges both for clinicians and clinical laboratories. Untreated, it may cause morbidly or death, but effective therapy is available, if administered timely. However, the diagnosis of ethylene glycol poisoning is not always straightforward. Thus, measurement of serum ethylene glycol, and ideally glycolic acid, its major toxic metabolite in serum, is definitive. Yet measurement of these structurally rather simple compounds is but simple. This review encompasses an assessment of analytical methods for the analytes relevant for the diagnosis and prognosis of ethylene glycol poisoning and of the role of the ethylene glycol metabolites, glycolic and oxalic acids, in its toxicity.
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Affiliation(s)
- William H Porter
- Department of Pathology and Laboratory Medicine, University of Kentucky Medical Center, Lexington, KY, United States.
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Dried blood spot punches for confirmation of suspected γ-hydroxybutyric acid intoxications: validation of an optimized GC–MS procedure. Bioanalysis 2011; 3:2271-81. [DOI: 10.4155/bio.11.204] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: γ-hydroxybutyric acid ( GHB ), notorious as a club- and date-rape drug, was quantified in dried blood spots (DBS) by punching out a disc, followed by ‘on-spot’ derivatization and analysis by GC–MS. Results: A homogenous distribution in DBS was demonstrated and accurate results were obtained when analyzing a disc punched out from a 20–35 µl spot, regardless the hematocrit of the blood sample. Validation based on US FDA and European Medicines Agency guidelines was performed, with a calibration range covering 2–100 µg/ml. Conclusion: A sensitive GC–MS method for GHB analysis in DBS was successfully optimized and validated. The successful analysis of DBS collected from GHB abusers suggests the routine applicability of the DBS sampling technique for GHB analysis in toxicological cases.
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Roberts DM, Smith MW, Gopalakrishnan M, Whittaker G, Day RO. Extreme γ-Butyrolactone Overdose With Severe Metabolic Acidosis Requiring Hemodialysis. Ann Emerg Med 2011; 58:83-5. [DOI: 10.1016/j.annemergmed.2011.01.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 01/15/2011] [Accepted: 01/24/2011] [Indexed: 11/25/2022]
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A validated GC-MS procedure for fast, simple, and cost-effective quantification of glycols and GHB in human plasma and their identification in urine and plasma developed for emergency toxicology. Anal Bioanal Chem 2011; 400:411-4. [DOI: 10.1007/s00216-011-4760-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 01/31/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
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19
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Brown SD, Melton TC. Trends in bioanalytical methods for the determination and quantification of club drugs: 2000-2010. Biomed Chromatogr 2010; 25:300-21. [DOI: 10.1002/bmc.1549] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 09/09/2010] [Accepted: 09/10/2010] [Indexed: 11/10/2022]
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20
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Determination of gamma-hydroxybutyric acid in dried blood spots using a simple GC-MS method with direct “on spot” derivatization. Anal Bioanal Chem 2010; 398:2173-82. [DOI: 10.1007/s00216-010-4183-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 08/13/2010] [Accepted: 08/30/2010] [Indexed: 01/18/2023]
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21
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False Positive Ethylene Glycol Determination by Spectrophotometry in the Presence of Severe Lactic Acidosis and Ketosis. Ann Emerg Med 2010; 56:75-6. [DOI: 10.1016/j.annemergmed.2010.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 02/09/2010] [Accepted: 02/10/2010] [Indexed: 11/22/2022]
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22
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Cooreman S, Cuypers E, De Doncker M, Van Hee P, Uyttenbroeck W, Neels H. Comparison of three immunoassays and one GC-MS method for the determination of valproic acid. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.immbio.2008.01.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Ha J, Hyun Yoon T, Wang Y, Musgrave CB, Brown GE. Adsorption of organic matter at mineral/water interfaces: 7. ATR-FTIR and quantum chemical study of lactate interactions with hematite nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:6683-6692. [PMID: 18522441 DOI: 10.1021/la800122v] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The interaction of the l-lactate ion ( l-CH3CH(OH)COO(-), lact(-1)) with hematite (alpha-Fe2O3) nanoparticles (average diameter 11 nm) in the presence of bulk water at pH 5 and 25 degrees C was examined using a combination of (1) macroscopic uptake measurements, (2) in situ attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, and (3) density functional theory modeling at the B3LYP/6-31+G* level. Uptake measurements indicate that increasing [ lact(-1)]aq results in an increase in lact(-1) uptake and a concomitant increase in Fe(III) release as a result of the dissolution of the hematite nanoparticles. The ATR-FTIR spectra of aqueous lact(-1) and lact(-1) adsorbed onto hematite nanoparticles at coverages ranging from 0.52 to 5.21 micromol/m2 showed significant differences in peak positions and shapes of carboxyl group stretches. On the basis of Gaussian fits of the spectra, we conclude that lact(-1) is present as both outer-sphere and inner-sphere complexes on the hematite nanoparticles. No significant dependence of the extent of lact(-1) adsorption on background electrolyte concentration was found, suggesting that the dominant adsorption mode for lact(-1) is inner sphere under these conditions. On the basis of quantum chemical modeling, we suggest that inner-sphere complexes of lact(-1) adsorbed on hematite nanoparticles occur dominantly as monodentate, mononuclear complexes with the hydroxyl functional group pointing away from the Fe(III) center.
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Affiliation(s)
- Juyoung Ha
- Surface & Aqueous Geochemistry Group, Department of Geological & Environmental Sciences, Stanford University, Stanford, CA 94305-2115, USA.
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Mercer JW, Oldfield LS, Hoffman KN, Shakleya DM, Bell SC. Comparative analysis of gamma-hydroxybutyrate and gamma-hydroxyvalerate using GC/MS and HPLC. J Forensic Sci 2007; 52:383-8. [PMID: 17316236 DOI: 10.1111/j.1556-4029.2007.00392.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper describes two analytical techniques used to separate and quantify gamma-hydroxybutyrate (GHB) and gamma-hydroxyvalerate (GHV). The first technique was a N,O-bis(trimethylsilyl)triflouro-acetimide-trimethylchlorosilane derivatization, followed by gas chromatography/mass spectrometry analysis using an HP-5 capillary column at a rate of 1.0 mL/min with a run time of 9.25 min. This technique was found to be sensitive (LOD 1 pg on column) and gave a low average error (5%) in a beverage study. When supplemented by a surrogate spike, the method yielded 97% analyte recovery from beverages. The second technique was high-performance liquid chromatography/UV (HPLC/UV) using a C-18 column with a (20:80% v/v) methanol:dibasic phosphoric buffer (10 mM, pH 3) at a rate of 1.00 mL/min with a run time of 7.5 min. UV detection occurred at 254 nm. This method was found to be less sensitive (LOD 0.05 microg on column) for direct analysis of aqueous samples. To remove interferences seen in the beverage study, a liquid-liquid extraction before HPLC analysis was tested. However, a decreased sensitivity (LOD 100 microg on column) and irreproducible peak profiles resulted.
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Affiliation(s)
- Jennifer W Mercer
- C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, WV 26056, USA.
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