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Capoun T, Krykorkova J. Internal Standards for Quantitative Analysis of Chemical Warfare Agents by the GC/MS Method: Nerve Agents. JOURNAL OF ANALYTICAL METHODS IN CHEMISTRY 2020; 2020:8857210. [PMID: 32850173 PMCID: PMC7439166 DOI: 10.1155/2020/8857210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
General conditions and requirements for an internal standard useful in the determination of chemical warfare agents (CWAs) by the method of gas chromatography coupled with mass detection (GC/MS) were defined. The determination is based on a GC/MS analysis of a mixture of a CWA with an internal standard, conversion of the TIC chromatogram to a chromatogram extracted at a particular m/z ratio, and calculation of the CWA concentration from the internal standard concentration, response factor, and chromatographic peak areas. Available internal standards were identified, and they were verified for seven organophosphorus nerve-paralysing agents. Corresponding response factors were determined as a ratio of gradients of the linear functions of the peak area and compound concentration. Linearity, repeatability, and accuracy of the measurements were evaluated. The determination can be performed on all GC/MS systems of the Fire Rescue Service of the Czech Republic (FRS), where no CWA standards are available.
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Affiliation(s)
- Tomas Capoun
- Ministry of Interior—Directorate General of the Fire Rescue Service CR, Population Protection Institute, Na Luzci 204, Lazne Bohdanec 533 41, Czech Republic
| | - Jana Krykorkova
- Ministry of Interior—Directorate General of the Fire Rescue Service CR, Population Protection Institute, Na Luzci 204, Lazne Bohdanec 533 41, Czech Republic
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2
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Balanco JMF, Sussmann RAC, Verdaguer IB, Gabriel HB, Kimura EA, Katzin AM. Tocopherol biosynthesis in Leishmania ( L.) amazonensis promastigotes. FEBS Open Bio 2019; 9:743-754. [PMID: 30984548 PMCID: PMC6443866 DOI: 10.1002/2211-5463.12613] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 01/17/2019] [Accepted: 02/12/2019] [Indexed: 01/25/2023] Open
Abstract
Leishmaniasis is a neglected disease caused by a trypanosomatid protozoan of the genus Leishmania. Most drugs used to treat leishmaniasis are highly toxic, and the emergence of drug‐resistant strains has been observed. Therefore, new therapeutic targets against leishmaniasis are required. Several isoprenoid compounds, including dolichols or ubiquinones, have been shown to be important for cell viability and proliferation in various trypanosomatid species. Here, we detected the biosynthesis of tocopherol in Leishmania (L.) amazonensis promastigotes in vitro through metabolic labelling with [1‐(n)‐3H]‐phytol. Subsequently, we confirmed the presence of vitamin E in the parasite by gas chromatography–mass spectrometry. Treatment with usnic acid or nitisinone, inhibitors of precursors of vitamin E synthesis, inhibited growth of the parasite in a concentration‐dependent manner. This study provides the first evidence of tocopherol biosynthesis in a trypanosomatid and suggests that inhibitors of the enzyme 4‐hydroxyphenylpyruvate dioxygenase may be suitable for use as antileishmanial compounds. Database The amino acid sequence of a conserved hypothetical protein [Leishmania mexicana MHOM/GT/2001/U1103] has been deposited in GenBank (CBZ28005.1)
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Affiliation(s)
- José Mário F Balanco
- Department of Parasitology Institute of Biomedical Sciences University of São Paulo Brazil
| | - Rodrigo A C Sussmann
- Department of Parasitology Institute of Biomedical Sciences University of São Paulo Brazil
| | - Ignasi B Verdaguer
- Department of Parasitology Institute of Biomedical Sciences University of São Paulo Brazil
| | - Heloisa B Gabriel
- Department of Parasitology Institute of Biomedical Sciences University of São Paulo Brazil
| | - Emilia A Kimura
- Department of Parasitology Institute of Biomedical Sciences University of São Paulo Brazil
| | - Alejandro M Katzin
- Department of Parasitology Institute of Biomedical Sciences University of São Paulo Brazil
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Saha S, Walia S, Kundu A, Kaur C, Singh J, Sisodia R. Capsaicinoids, Tocopherol, and Sterols Content in Chili (Capsicumsp.) by Gas Chromatographic-Mass Spectrometric Determination. INTERNATIONAL JOURNAL OF FOOD PROPERTIES 2014. [DOI: 10.1080/10942912.2013.833222] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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4
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Liu H, Fang G, Zhu H, Wang S. Application of Molecularly Imprinted Polymer Appended onto CdSe/ZnS Quantum Dots for Optosensing of Tocopherol in Rice. FOOD ANAL METHOD 2013. [DOI: 10.1007/s12161-013-9768-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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5
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Sussmann RA, Angeli CB, Peres VJ, Kimura EA, Katzin AM. Intraerythrocytic stages of Plasmodium falciparum
biosynthesize vitamin E. FEBS Lett 2011; 585:3985-91. [DOI: 10.1016/j.febslet.2011.11.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 10/28/2011] [Accepted: 11/02/2011] [Indexed: 01/16/2023]
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Li ZH, Wang Q, Ruan X, Pan CD, Jiang DA. Phenolics and plant allelopathy. Molecules 2010; 15:8933-52. [PMID: 21139532 PMCID: PMC6259130 DOI: 10.3390/molecules15128933] [Citation(s) in RCA: 228] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 11/21/2010] [Accepted: 11/25/2010] [Indexed: 11/16/2022] Open
Abstract
Phenolic compounds arise from the shikimic and acetic acid (polyketide) metabolic pathways in plants. They are but one category of the many secondary metabolites implicated in plant allelopathy. Phenolic allelochemicals have been observed in both natural and managed ecosystems, where they cause a number of ecological and economic problems, such as declines in crop yield due to soil sickness, regeneration failure of natural forests, and replanting problems in orchards. Phenolic allelochemical structures and modes of action are diverse and may offer potential lead compounds for the development of future herbicides or pesticides. This article reviews allelopathic effects, analysis methods, and allelopathic mechanisms underlying the activity of plant phenolic compounds. Additionally, the currently debated topic in plant allelopathy of whether catechin and 8-hydroxyquinoline play an important role in Centaurea maculata and Centaurea diffusa invasion success is discussed. Overall, the main purpose of this review is to highlight the allelopacthic potential of phenolic compounds to provide us with methods to solve various ecology problems, especially in regard to the sustainable development of agriculture, forestry, nature resources and environment conservation.
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Affiliation(s)
- Zhao-Hui Li
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China
| | - Qiang Wang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China
- Authors to whom correspondence should be addressed; E-Mails: (Q.W.); (D.-A.J.); Tel.: +86-574-88134338 (Q.W.); +86-571-88206461(D.-A.J.); Fax: +86-574-88229545 (Q.W.); +86-571-88206461(D.-A.J.)
| | - Xiao Ruan
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, China
| | - Cun-De Pan
- College of Forest, Xinjiang Agricultural University, Urumqi 830052, China
| | - De-An Jiang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, China
- Authors to whom correspondence should be addressed; E-Mails: (Q.W.); (D.-A.J.); Tel.: +86-574-88134338 (Q.W.); +86-571-88206461(D.-A.J.); Fax: +86-574-88229545 (Q.W.); +86-571-88206461(D.-A.J.)
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Biomarkers of exposure to vitamins A, C, and E and their relation to lipid and protein oxidation markers. Eur J Nutr 2008; 47 Suppl 2:3-18. [DOI: 10.1007/s00394-008-2003-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Medeiros PM, Simoneit BRT. Gas chromatography coupled to mass spectrometry for analyses of organic compounds and biomarkers as tracers for geological, environmental, and forensic research. J Sep Sci 2007; 30:1516-36. [PMID: 17623433 DOI: 10.1002/jssc.200600399] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Gas chromatography, especially when coupled with mass spectrometry, is the analytical method of choice for elucidation of biomarker compounds present in organic mixtures extracted from geological, environmental, and biological samples. This review describes the biomarker concept, i. e., the precursor natural products to the geological/environmental derivatives, and their application as multi-tracers in the geosphere and ambient environment. The mass spectrometric methods currently utilized for such analyses are reviewed with a general key to the literature, and typical examples of applications using GC-MS are also described.
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Affiliation(s)
- Patricia M Medeiros
- Environmental and Petroleum Research Group, College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, USA
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Demirkaya F, Kadioglu Y. Simple GC-FID method development and validation for determination of alpha-tocopherol (vitamin E) in human plasma. ACTA ACUST UNITED AC 2006; 70:363-8. [PMID: 17292967 DOI: 10.1016/j.jbbm.2006.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2005] [Revised: 08/13/2006] [Accepted: 08/13/2006] [Indexed: 11/20/2022]
Abstract
This paper describes the development and validation of a novel GC-FID method for the determination of alpha-tocopherol concentration in human plasma which does not requires derivatization. The standard solutions and the plasma working solutions were prepared in absolute ethanol. To determine the concentration of alpha-tocopherol in human plasma, an aliquot of the plasma sample was deproteinized with ethanol. alpha-tocopherol was extracted with a mixture of hexane and dichloromethane (9:1). GC separation was performed using a HP-5 capillary column. Nitrogen was used as carrier gas at a flow-rate of 2 ml min(-1). Calibration curves were linear over the concentration range 1-30 microg ml(-1) (for standard solutions and solutions without endogenous alpha-tocopherol in plasma) and 5-34 microg ml(-1) (for solutions with endogenous alpha-tocopherol in plasma). Absolute recovery, precision, sensitivity and accuracy assays were carried out. The analytical recovery of alpha-tocopherol from plasma averaged 97.44%. The limit of quantification (LOQ) and the limit of detection (LOD) of method for standard samples were 0.35 microg.ml(-1) and 0.30 microg.ml(-1), respectively. Within-day and between-day precision, expressed as the relative standard deviation (RSD) were less than 4%, and accuracy (relative error) was better than 8%. This novel method, developed and validated in our laboratory, could be successfully applied to the in-vivo determination of alpha-tocopherol. The endogenous alpha-tocopherol amounts in blood of twelve healthy volunteers with no vitamin drug usage were measured with this method.
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Affiliation(s)
- Fatma Demirkaya
- Department of Analytical Chemistry, Faculty of Pharmacy, Ataturk University, 25240, Erzurum, Turkey
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Simoneit BRT. A review of current applications of mass spectrometry for biomarker/molecular tracer elucidation. MASS SPECTROMETRY REVIEWS 2005; 24:719-765. [PMID: 15534872 DOI: 10.1002/mas.20036] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Mass spectrometry, especially coupled with gas chromatography or tandem, is the analytical method of choice in elucidation of biomarker compounds present in organic mixtures extracted from geological, environmental, or biological samples. This review describes the biomarker concept; i.e., the precursor natural products to the geological/environmental derivatives, and their application as tracers in the geosphere and ambient environment. The mass spectrometric methods currently utilized for such analyses are reviewed, and typical examples of applications are described with a general key to the literature.
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Affiliation(s)
- Bernd R T Simoneit
- Environmental and Petroleum Research Group, College of Oceanic and Atmospheric Sciences and Department of Chemistry, Oregon State University, Corvallis, Oregon 97331-5503, USA.
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11
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Budnikov GK, Ziyatdinova GK. Antioxidants As Analytes in Analytical Chemistry. JOURNAL OF ANALYTICAL CHEMISTRY 2005. [DOI: 10.1007/s10809-005-0146-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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12
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Seal AN, Pratley JE, Haig T, An M. Identification and quantitation of compounds in a series of allelopathic and non-allelopathic rice root exudates. J Chem Ecol 2005; 30:1647-62. [PMID: 15537165 DOI: 10.1023/b:joec.0000042074.96036.14] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An investigation of the chemical basis for rice allelopathy to the rice weed arrowhead (Sagittaria montevidensis) was undertaken using GC/MS and GC/MS/MS techniques. Twenty-five compounds were isolated and identified from the root exudates of both allelopathic and non-allelopathic rice varieties. Phenolics, phenylalkanoic acids, and indoles were among the chemical classes identified. Two indoles previously unreported in rice were detected in the exudates, 5-hydroxy-2-indolecarboxylic acid and 5-hydroxyindole-3-acetic acid. Several other compounds identified in this study have not previously been reported in rice root exudates, namely mercaptoacetic acid, 4-hydroxyphenylacetic acid, and 4-vinylphenol. The levels of 15 compounds present in the exudates were quantified using GC/MS/MS. Six of the seven most abundant compounds were phenolic acids. Significant differences exist between the allelopathic and non-allelopathic cultivars in their production of three of these six compounds. Greater amounts of trans-ferulic acid, p-hydroxybenzoic acid, and caffeic acid were detected in the exudates of allelopathic cultivars. The seventh compound, abietic acid, was significantly higher in the non-allelopathic cultivars.
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Affiliation(s)
- Alexa N Seal
- Farrer Centre, Charles Sturt University Locked Bag 588 Wagga Wagga, New South Wales, Australia 2678.
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Richelle M, Tavazzi I, Fay LB. Simultaneous determination of deuterated and non-deuterated alpha-tocopherol in human plasma by high-performance liquid chromatography. J Chromatogr B Analyt Technol Biomed Life Sci 2003; 794:1-8. [PMID: 12888192 DOI: 10.1016/s1570-0232(03)00360-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Labelled tocopherol is used to evaluate its absorption by biodiscriminating the dietary intake from the endogenous tocopherol pool of subject. A normal-phase high-performance liquid chromatographic method is described for the easy separation and quantification of deuterated (d(6)) and non-deuterated alpha-tocopherol. The alpha-tocopherol isotopomers were extracted from plasma triacylglycerol-rich lipoproteins in hexane, separated by two EC Nucleosil columns in series with a mobile phase of hexane-isopropanol (659.34:0.786, w/w) running isocratically. The detection of d(6)-alpha-tocopherol was performed by its UV absorbance at 297 nm with a limit of detection of 34 pmol/ml, a limit of quantification of 83 pmol/ml and a range of determination of 34-9905 pmol/ml. Between- and within-assay RSDs were 2.4% (n=10) and 2.7% (n=5), respectively.
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Affiliation(s)
- Myriam Richelle
- Department of Nutrition, Nestlé Research Center, PO Box 44, CH-1000 26, Lausanne, Switzerland.
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Abstract
The objective of this study was to determine whether the ability of the human placenta to transfer glucose and fatty acids is related to normal fetal growth. The intrinsic nutrient transport capacity of the placenta was measured under standardized conditions during in vitro perfusion of 30 human term placentas and related to birth weight (range 2640-4640g), birth weight centile (8th-99th), ponderal index (2.43-3.69), placental weight (418-1030g) and placental:fetal weight (0.14-0.31). There was no statistically significant change in the rate of nutrient transfer per placenta or per kg fetal weight, with birth weight, birth weight centile, ponderal index, placental weight and placental:fetal weight. There was a weak but significant relationship (P=0.020, r(2)=9 per cent) between the ratio of glucose to fatty acid transport and birth weight centile, largely due to the high ratio found in the lowest birth weight quartile where the babies are thinnest. This study provides no evidence that placental nutrient transport capacity limits fetal growth across a wide range of birth weights in normal pregnancies. It is proposed that the fetus itself may regulate placental nutrient transport in vivo via the fetal cardiac output and the rate of fetal nutrient utilization.
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Affiliation(s)
- P Haggarty
- Rowett Research Institute, Aberdeen, AB2 9SB, UK.
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15
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Oliveira EJ, Watson DG. Chromatographic techniques for the determination of putative dietary anticancer compounds in biological fluids. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 764:3-25. [PMID: 11817034 DOI: 10.1016/s0378-4347(01)00401-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although a great number of papers demonstrate an association between high intake of fruits and vegetables and reduced risk of certain types of cancer, the epidemiological evidence is not conclusive. The identification and quantification of specific dietary anticancer compounds in plasma, urine and tissues is an important aspect of this research. We surveyed the recent literature for original papers which involved the use of separation techniques for the detection and quantification in biological fluids and tissues of putative anticancer compounds which are present in the diet. The compounds included in this review are flavonoids, phytoestrogens, carotenoids, retinoids, vitamin E and ascorbic acid. The review covers papers published in the last 3 years. For each class of compounds we discuss the sample preparation, chromatographic conditions, and validation of the methods used, in order to identify current trends in the bioanalysis of each class of these substances.
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Affiliation(s)
- E J Oliveira
- Department of Pharmaceutical Sciences, University of Strathclyde, Strathclyde Institute of Biomedical Sciences, Glasgow, UK
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16
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Moreno Frías M, Garrido Frenich A, Martínez Vidal JL, Mateu Sánchez M, Olea F, Olea N. Analyses of lindane, vinclozolin, aldrin, p,p'-DDE, o,p'-DDT and p,p'-DDT in human serum using gas chromatography with electron capture detection and tandem mass spectrometry. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 760:1-15. [PMID: 11522051 DOI: 10.1016/s0378-4347(01)00212-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A sensitive, selective and reliable procedure was developed and validated to determine organochlorinated compounds, which present endocrine-disrupting effects, lindane, vinclozolin, aldrin, p,p'-DDT, o,p'-DDT and p,p'-DDE, in human serum. The analytical methodology combines serum extraction with organic solvents, clean-up of the organic extract using acid treatment with H2SO4, elution of the cleaned-up extract through liquid column chromatography system and analysis of the fraction eluted by gas chromatography (GC) with electron capture detection (ECD) and tandem mass spectrometry (MS-MS) detection mode. Performance characteristics, such as linearity, sensitivity, precision, accuracy or recovery, of both chromatographic methods were studied. The proposed analytical methodology was applied to analyse the target compounds in serum samples from women living in agricultural areas of Almería (Spain). Comparison of the MS-MS and the ECD results was made and the advantage of the MS-MS operation mode to determine endocrine disrupting compounds in complex matrices is also presented.
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Affiliation(s)
- M Moreno Frías
- Department of Analytical Chemistry, University of Almería, Spain
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Infante JP, Huszagh VA. Impaired arachidonic (20:4n-6) and docosahexaenoic (22:6n-3) acid synthesis by phenylalanine metabolites as etiological factors in the neuropathology of phenylketonuria. Mol Genet Metab 2001; 72:185-98. [PMID: 11243724 DOI: 10.1006/mgme.2001.3148] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The recent literature on polyunsaturated fatty acid metabolism in phenylketonuria (PKU) is critically analyzed. The data suggest that developmental impairment of the accretion of brain arachidonic (20:4n-6) and docosahexaenoic (22:6n-3, DHA) acids is a major etiological factor in the microcephaly and mental retardation of uncontrolled PKU and maternal PKU. These fatty acids appear to be synthesized by the recently elucidated carnitine-dependent, channeled, mitochondrial fatty acid desaturases for which alpha-tocopherolquinone (alpha-TQ) is an essential enzyme cofactor. alpha-TQ can be synthesized either de novo or from alpha-tocopherol. The fetus and newborn would primarily rely on de novo alpha-TQ synthesis for these mitochondrial desaturases because of low maternal transfer of alpha-tocopherol. Homogentisate, a pivotal intermediate in the de novo pathway of alpha-TQ synthesis, is synthesized by 4-hydroxyphenylpyruvate dioxygenase. The major catabolic products of excess phenylalanine, viz. phenylpyruvate and phenyllactate, are proposed to inhibit alpha-TQ synthesis at the level of the dioxygenase reaction by competing with its 4-hydroxyphenylpyruvate substrate, thus leading to a developmental impairment of 20:4n-6 and 22:6n-3 synthesis in uncontrolled PKU and fetuses of PKU mothers. The data suggest that dietary supplementation with carnitine, 20:4n-6, and 22:6n-3 may have therapeutic value for PKU mothers and for PKU patients who have been shown to have a low plasma status of these essential metabolites.
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Affiliation(s)
- J P Infante
- Institute for Theoretical Biochemistry and Molecular Biology, Ithaca, New York 14852, USA.
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18
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Affiliation(s)
- R C Murphy
- Division of Cell Biology, National Jewish Medical and Research Center, 1400 Jackson Street, Denver, Colorado 80206, USA.
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19
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Comparison of gas chromatography with NPD, MS, and tandem MS-MS in the multiresidue analysis of pesticides in environmental waters. Chromatographia 2000. [DOI: 10.1007/bf02789761] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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High-pressure ion source combined with an in-axis ion trap mass spectrometer. 1. Instrumentation and applications. Anal Chem 2000; 72:5055-62. [PMID: 11055728 DOI: 10.1021/ac000171m] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new combination of a dual EI/CI ion source with a quadrupole ion trap mass spectrometer has been realized in order to efficiently produce negative ions in the reaction cell. Analysis of volatile compounds was performed under negative ion chemical ionization (NICI) during a reaction period where selected reactant negative ions, previously produced in the external ion source, were allowed to interact with molecules, introduced by hyphenated techniques such as gas chromatography. The O2*-, CH3O-, and Cl- reactant ions were used in this study to ensure specific ion/molecule interactions such as proton transfer, nucleophilic displacement, or charge exchange processes, respectively leading to even-electron species, i.e., deprotonated [M - H]- molecules, diagnostic [M - R]- ions, or odd-electron M*- molecular species. The reaction orientation depends on the thermochemistry of reactions within kinetic controls. First analytical results are presented here for the trace-level detection of several contaminants under NICI/Cl- conditions. Phosphorus-containing compounds (malathion, ethyl parathion, and methyl parathion as representative for pesticides) and nitro-containing compounds (2,4,6-trinitrotoluene for explosive material) have been chosen in order to explore the analytical ability of this promising instrumental coupling.
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Frenich AG, Vidal JL, Frías MM, Olea-Serrano F, Olea N. Quantitative determination of endocrine- disrupting polychlorinated biphenyls and organochlorinated pesticides in human serum using gas chromatography with electron-capture detection and tandem mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:967-975. [PMID: 10972996 DOI: 10.1002/1096-9888(200008)35:8<967::aid-jms24>3.0.co;2-v] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A sensitive, selective and reliable procedure was developed and validated to determine organochlorinated compounds, which have endocrine-disrupting effects, in human serum. Target compounds were selected between polychlorinated biphenyls and organochlorinated pesticides. Sample workup consisted of (1) extraction of serum with organic solvents, (2) clean-up of the organic extract using acid treatment with H(2)SO(4), (3) elution of the cleaned-up extract through a liquid column chromatographic system and (4) analysis of the fraction eluted by gas chromatography with electron capture detection (ECD) and tandem mass spectrometry (MS/MS) detection. Performance characteristics, such as linearity, sensitivity, precision, accuracy and recovery, of both chromatographic methods were studied. The proposed analytical methodology was applied to determine the target compounds in serum samples from women living in agricultural areas of Almería (Spain). The results show the advantage of MS/MS over ECD in the analysis of real human serum samples where matrix interferences can be confused with target pesticides.
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Affiliation(s)
- A G Frenich
- Department of Analytical Chemistry, University of Almería, 04071 Almería, Spain
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Gee AJ, Groen LA, Johnson ME. Ion trap mass spectrometry of trimethylsilylamides following gas chromatography. JOURNAL OF MASS SPECTROMETRY : JMS 2000; 35:305-310. [PMID: 10767758 DOI: 10.1002/(sici)1096-9888(200003)35:3<305::aid-jms917>3.0.co;2-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Fatty acid amides are a class of compounds with newly discovered biological activity. The ion trap mass spectrometric characteristics of silylated fatty acid amides were examined. Silylation of primary fatty acid amides is required prior to gas chromatography owing to thermal instability of the underivatized compound. The trimethylsilylated amides do not yield a molecular ion under normal electron ionization conditions (70 eV). With methane as a chemical ionization gas, the [M+H]+ ion appears. The [M+H]+ ion also appears when the helium buffer gas pressure is increased in the ion trap. There are three fragments other than the [M+H]+ peak that are predominant in the ion trap mass spectra of these compounds. Two of the fragments have been reported previously, namely the m/z 59 and the [M-71]+ fragments. The fragment of m/z 72 was identified and is the result of a rearrangement. Isotopic labeling was used to confirm fragment identity and the composition of the rearrangement products. Fragmentation patterns were affected by the amide chain length and concentration.
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Affiliation(s)
- A J Gee
- Duquesne University, Department of Chemistry and Biochemistry, Pittsburgh, Pennsylvania 15282-1530, USA
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Wu H, Haig E, Pratley J, Lemerle D, An M. Simultaneous determination of phenolic acids and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one in wheat (Triticum aestivum L.) by gas chromatography-tandem mass spectrometry. J Chromatogr A 1999; 864:315-21. [PMID: 10669299 DOI: 10.1016/s0021-9673(99)01034-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A procedure using gas chromatography and tandem mass spectrometry (GC-MS-MS) has been developed for the identification and quantification of some allelochemicals in wheat (Triticum aestivum L.). The quantities of allelochemicals in wheat shoots ranged from 2.9 to 110 mg per kilogram of dry shoot residues. Compared with gas chromatography-mass spectrometry (GC-MS), the GC-MS-MS technique significantly increased instrument selectivity and sensitivity, thereby providing more reliable quantitation results in the determination of the phytotoxic compounds examined during this allelopathy research.
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Affiliation(s)
- H Wu
- Farrer Centre for Conservation Farming, Charles Sturt University, Wagga Wagga, NSW, Australia.
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