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Opekar S, Kvíčala J, Moos M, Pejchal V, Šimek P. Mechanism of Alkyl Chloroformate-Mediated Esterification of Carboxylic Acids in Aqueous Media. J Org Chem 2021; 86:16293-16299. [PMID: 34546734 DOI: 10.1021/acs.joc.1c01546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The protection of carboxyl groups by esterification has been the most common method in macroscale and microscale chemistries. The esterification is usually conducted under anhydrous conditions; however, in biological chemistry and related fields, the reaction is of major concern in aqueous environments. Immediate esterification of the carboxyl in aqueous alcoholic media driven by an alkyl chloroformate and pyridine has been such a method which has found widespread use in many research and industrial laboratories. Nevertheless, the reaction mechanism has not yet been investigated, to our knowledge, and is not well understood. Herein, we describe the reaction intermediates and demonstrate that the reaction proceeds via a continual formation of the N-acylpyridinium intermediate decomposed by several reaction channels to the final ester. The understanding of the mechanism could encourage novel laboratory applications of this important esterification method.
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Affiliation(s)
- Stanislav Opekar
- Czech Academy of Sciences, Biology Centre, Institute of Entomology, Branišovská 31/1160, České Budějovice 37005, Czech Republic
| | - Jaroslav Kvíčala
- Department of Organic Chemistry, University of Chemistry and Technology Prague, Technická 5, 16628 Prague 6, Czech Republic
| | - Martin Moos
- Czech Academy of Sciences, Biology Centre, Institute of Entomology, Branišovská 31/1160, České Budějovice 37005, Czech Republic
| | - Vladimír Pejchal
- Faculty of Chemical Technology, University of Pardubice, Studentská 95, 53210 Pardubice, Czech Republic
| | - Petr Šimek
- Czech Academy of Sciences, Biology Centre, Institute of Entomology, Branišovská 31/1160, České Budějovice 37005, Czech Republic
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Fully Automated Quantitative Measurement of Serum Organic Acids via LC-MS/MS for the Diagnosis of Organic Acidemias: Establishment of an Automation System and a Proof-of-Concept Validation. Diagnostics (Basel) 2021; 11:diagnostics11122195. [PMID: 34943431 PMCID: PMC8700112 DOI: 10.3390/diagnostics11122195] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/20/2022] Open
Abstract
Gas chromatography-mass spectrometry has been widely used to analyze hundreds of organic acids in urine to provide a diagnostic basis for organic acidemia. However, it is difficult to operate in clinical laboratories on a daily basis due to sample pretreatment processing. Therefore, we aimed to develop a fully automated system for quantifying serum organic acids using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pretreatment CLAM-2030 device was connected to an LC-MS/MS system for processing serum under optimized conditions, which included derivatizing serum organic acids using 3-Nitrophenylhydrazine. The derivatized organic acids were separated on a reverse-phase Sceptor HD-C column and detected using negative-ion electrospray ionization multiple reaction monitoring MS. The automated pretreatment-LC-MS/MS system processed serum in less than 1 h and analyzed 19 serum organic acids, which are used to detect organic acidemias. The system exhibited high quantitative sensitivity ranging from approximately 2 to 100 µM with a measurement reproducibility of 10.4% CV. Moreover, a proof-of-concept validation of the system was performed using sera from patients with propionic acidemia (n = 5), methylmalonic acidemia (n = 2), and 3-methylcrotonylglycinuria (n = 1). The levels of marker organic acids specific to each disease were significantly elevated in the sera of the patients compared to those in control samples. The automated pretreatment-LC-MS/MS system can be used as a rapid in-hospital system to measure organic acid levels in serum for the diagnosis of organic acidemias.
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Patel BR, Noroozifar M, Kerman K. Prussian blue-doped nanosized polyaniline for electrochemical detection of benzenediol isomers. Anal Bioanal Chem 2020; 412:1769-1784. [PMID: 32043201 DOI: 10.1007/s00216-020-02400-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 12/17/2019] [Accepted: 01/09/2020] [Indexed: 12/14/2022]
Abstract
Simultaneous speciation of benzenediol isomers (BDIs), 1,2-benzenediol (catechol, CC), 1,3-benzenediol (resorcinol, RS), and 1,4-benzenediol (hydroquinone, HQ), was investigated by differential pulse voltammetry (DPV) using a graphite paste electrode (GPE) modified with Prussian blue-polyaniline nanocomposite. The modified GPE showed good stability, sensitivity, and selectivity properties for all the three BDIs. Prussian blue-doped nanosized polyaniline (PBNS-PANI) was synthesized first by using mechanochemical reactions between aniline and ferric chloride hexahydrate as the oxidants and then followed by the addition of potassium hexacyanoferrate(II) in a solid-state and template-free technique. The material was characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The DPV measurements are performed in phosphate electrolyte solution with pH 4.0 at a potential range of - 0.1 to 1.0 V. The proposed modified electrode displayed a strong, stable, and continuous three well-separated oxidation peaks towards electrooxidation at potentials 0.20, 0.31, and 0.76 V for HQ, CC, and RS, respectively. The calibration curves were linear from 1 to 350.5 μM for both HQ and CC, while for RS, it was from 2 to 350.5 μM. The limit of detection was determined to be 0.18, 0.01, and 0.02 μM for HQ, CC, and RS, respectively. The analytical performance of the PBNS-PANI/GPE has been evaluated for simultaneous determination of HQ, CC, and RS in creek water, commercial hair dye, and skin whitening cream samples with satisfactory recoveries between 90 and 106%. Overall, we demonstrated that the presence of NS-PANI and PB resulted in a large redox-active surface area that enabled a promising analytical platform for simultaneous detection of BDIs. Graphical abstract.
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Affiliation(s)
- Bhargav R Patel
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Meissam Noroozifar
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
| | - Kagan Kerman
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada.
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Yamamoto S, Matsumoto A, Yui Y, Miyazaki S, Kumagai S, Hori H, Ichiba M. Concentration determination of urinary metabolites of N,N-dimethylacetamide by high-performance liquid chromatography-tandem mass spectrometry. J Occup Health 2018; 60:140-147. [PMID: 29213009 PMCID: PMC5886881 DOI: 10.1539/joh.17-0098-oa] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 11/08/2017] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES N,N-Dimethylacetamide (DMAC) is widely used in industry as a solvent. It can be absorbed through human skin. Therefore, it is necessary to determine exposure to DMAC via biological monitoring. However, the precision of traditional gas chromatography (GC) is low due to the thermal decomposition of metabolites in the high-temperature GC injection port. To overcome this problem, we have developed a new method for the simultaneous separation and quantification of urinary DMAC metabolites using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS Urine samples were diluted 10-fold in formic acid, and 1-μl aliquots were injected into the LC-MS/MS equipment. A C18 reverse-phase Octa Decyl Silyl (ODS) column was used as the analytical column, and the mobile phase consisted of a mixture of methanol and aqueous formic acid solution. RESULTS Urinary concentrations of DMAC and its known metabolites (N-hydroxymethyl-N-methylacetamide (DMAC-OH), N-methylacetamide (NMAC), and S- (acetamidomethyl) mercapturic acid (AMMA) ) were determined in a single run. The dynamic ranges of the calibration curves were 0.05-5 mg/l (r≥0.999) for all four compounds. The limits of detection for DMAC, DMAC-OH, NMAC, and AMMA in urine were 0.04, 0.02, 0.05, and 0.02 mg/l, respectively. Within-run accuracies were 96.5%-109.6% with relative standard deviations of precision being 3.43%-10.31%. CONCLUSIONS The results demonstrated that the proposed method could successfully quantify low concentrations of DMAC and its metabolites with high precision. Hence, this method is useful for evaluating DMAC exposure. In addition, this method can be used to examine metabolite behaviors in human bodies after exposure and to select appropriate biomarkers.
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Affiliation(s)
- Shinobu Yamamoto
- Department of Environmental Measurement and Control, University of Occupational and Environmental Health
- Department of Social Medicine, Saga University
| | | | | | | | - Shinji Kumagai
- Department of Occupational and Environmental Management, University of Occupational and Environmental Health
| | - Hajime Hori
- Department of Environmental Measurement and Control, University of Occupational and Environmental Health
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Ambati CSR, Yuan F, Abu-Elheiga LA, Zhang Y, Shetty V. Identification and Quantitation of Malonic Acid Biomarkers of In-Born Error Metabolism by Targeted Metabolomics. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2017; 28:929-938. [PMID: 28315235 DOI: 10.1007/s13361-017-1631-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 02/13/2017] [Accepted: 02/17/2017] [Indexed: 06/06/2023]
Abstract
Malonic acid (MA), methylmalonic acid (MMA), and ethylmalonic acid (EMA) metabolites are implicated in various non-cancer disorders that are associated with inborn-error metabolism. In this study, we have slightly modified the published 3-nitrophenylhydrazine (3NPH) derivatization method and applied it to derivatize MA, MMA, and EMA to their hydrazone derivatives, which were amenable for liquid chromatography- mass spectrometry (LC-MS) quantitation. 3NPH was used to derivatize MA, MMA, and EMA, and multiple reaction monitoring (MRM) transitions of the corresponding derivatives were determined by product-ion experiments. Data normalization and absolute quantitation were achieved by using 3NPH derivatized isotopic labeled compounds 13C2-MA, MMA-D3, and EMA-D3. The detection limits were found to be at nanomolar concentrations and a good linearity was achieved from nanomolar to millimolar concentrations. As a proof of concept study, we have investigated the levels of malonic acids in mouse plasma with malonyl-CoA decarboxylase deficiency (MCD-D), and we have successfully applied 3NPH method to identify and quantitate all three malonic acids in wild type (WT) and MCD-D plasma with high accuracy. The results of this method were compared with that of underivatized malonic acid standards experiments that were performed using hydrophilic interaction liquid chromatography (HILIC)-MRM. Compared with HILIC method, 3NPH derivatization strategy was found to be very efficient to identify these molecules as it greatly improved the sensitivity, quantitation accuracy, as well as peak shape and resolution. Furthermore, there was no matrix effect in LC-MS analysis and the derivatized metabolites were found to be very stable for longer time. Graphical Abstract ᅟ.
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Affiliation(s)
- Chandra Shekar R Ambati
- Metabolomics Core Facility, Molecular and Cellular Biology, Alkek Center for Molecular Discovery, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Furong Yuan
- Department of Biochemistry, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Lutfi A Abu-Elheiga
- Department of Biochemistry, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yiqing Zhang
- Metabolomics Core Facility, Molecular and Cellular Biology, Alkek Center for Molecular Discovery, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Vivekananda Shetty
- Metabolomics Core Facility, Molecular and Cellular Biology, Alkek Center for Molecular Discovery, Baylor College of Medicine, Houston, TX, 77030, USA.
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Pervova MG, Plotnikova KA, Chizhov DL, Pestov AV, Saloutin VI. Determination of glycols in glycol-containing oligomers using gas-liquid reaction chromatography. JOURNAL OF ANALYTICAL CHEMISTRY 2016. [DOI: 10.1134/s1061934816060137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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A new method for immediate derivatization of hydroxyl groups by fluoroalkyl chloroformates and its application for the determination of sterols and tocopherols in human serum and amniotic fluid by gas chromatography–mass spectrometry. J Chromatogr A 2014; 1339:154-67. [DOI: 10.1016/j.chroma.2014.03.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/13/2014] [Accepted: 03/03/2014] [Indexed: 01/02/2023]
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Holčapek M, Virelizier H, Chamot-Rooke J, Jandera P, Moulin C. Trace determination of glycols by HPLC with UV and electrospray ionization mass spectrometric detections. Anal Chem 2012; 71:2288-93. [PMID: 21662779 DOI: 10.1021/ac981087y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A high-performance liquid chromatography/mass spectrometry (HPLC/MS) method is developed for trace determination of glycols (ethylene glycol, 1,2- and 1,3-propylene glycols, and 2,3-butylene glycol) in water after derivatization with benzoyl chloride. Benzoyl esters of glycols are separated by microcolumn reversed-phase HPLC. Sensitivity and linearity of UV detection at 237 nm is compared with electrospray ionization mass spectrometric (ESI-MS) detection using selected ion monitoring. Limits of detection (LOD) and quantitation (LOQ) for UV detection are 1 and 2 mg/L, respectively. For ESI-MS detection, LOD and LOQ are in the ranges 10-25 and 20-50 μg/L, respectively. LOD obtained by ESI-MS for the determination of glycols is improved by 2-3 orders of magnitude in comparison to previously published methods. The effect of the structure of isomeric glycols on their electrospray mass spectra is discussed. The method has been applied for the determination of glycols in aqueous matrixes containing high concentrations of salts occurring in nuclear waste disposal treatment.
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Affiliation(s)
- M Holčapek
- Faculty of Chemical Technology, Department of Analytical Chemistry, University of Pardubice, nám. Čs.legií 565, 53210 Pardubice, Czech Republic, and CEA Saclay, DPE/SPCP/LASO, 91191 Gif sur Yvette Cedex, France
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Vincenti M, Fasano F, Valsania MC, Guarda P, Richardson SD. Application of the novel 5-chloro-2,2,3,3,4,4,5,5-octafluoro-1-pentyl chloroformate derivatizing agent for the direct determination of highly polar water disinfection byproducts. Anal Bioanal Chem 2010; 397:43-54. [DOI: 10.1007/s00216-010-3477-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 01/14/2010] [Accepted: 01/14/2010] [Indexed: 11/29/2022]
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Lakso HA, Appelblad P, Schneede J. Quantification of methylmalonic acid in human plasma with hydrophilic interaction liquid chromatography separation and mass spectrometric detection. Clin Chem 2008; 54:2028-35. [PMID: 18845771 DOI: 10.1373/clinchem.2007.101253] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Measurement of methylmalonic acid (MMA) in serum or plasma is useful for diagnosing cobalamin deficiency. We developed a method for quantifying MMA in plasma based on hydrophilic interaction liquid chromatography (HILIC) and single-stage negative electrospray ionization (ESI) mass spectrometry. METHODS We deproteinized plasma samples (200 microL) with 800 microL acidified acetonitrile containing 0.17 micromol/L deuterated MMA (D(3)-MMA) internal standard, centrifuged the samples, and injected 4 microL of the supernatant into the LC-MS instrument. Separation was achieved within 3 min on a Merck SeQuant ZIC-HILIC column with a mobile phase consisting of 4 volumes acetonitrile plus 1 volume 100 mmol/L ammonium acetate buffer, pH 4.5, at a flow rate of 400 microL/min. Subsequent column washing and reconditioning contributed to a total run time of 10 min. MMA and D(3)-MMA were quantified by single-ion monitoring (m/z 117.2 and 120.2, respectively) in negative ESI mode at a drying-gas flow rate of 10 L/min, 300 degrees C, and a capillary voltage of 3.0 kV. RESULTS The estimated limits of MMA quantification and detection were 0.09 micromol/L and 0.03 micromol/L, respectively, in plasma. The assay was linear to 200 micromol/L. Interassay and intraassay CVs were < or = 5% at all tested concentrations. Recoveries were 90%-93%. CONCLUSIONS This robust assay allows analysis of MMA in human plasma without derivatization. Sample preparation is simple and suitable for automation.
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Affiliation(s)
- Hans-Ake Lakso
- Department of Clinical Pharmacology, University of Umeå, Umeå, Sweden
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Judefeind A, van Rensburg PJ, Langelaar S, du Plessis J. Stable isotope dilution analysis of salicylic acid and hydroquinone in human skin samples by gas chromatography with mass spectrometric detection. J Chromatogr B Analyt Technol Biomed Life Sci 2007; 852:300-7. [PMID: 17336602 DOI: 10.1016/j.jchromb.2007.01.031] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2006] [Revised: 01/16/2007] [Accepted: 01/19/2007] [Indexed: 11/19/2022]
Abstract
A sensitive and accurate gas chromatographic-mass spectrometric (GC-MS) method has been developed for the quantitative determination of salicylic acid (SA) and hydroquinone (HQ) from human skin samples and cosmetic emulsions. Deuterium labeled SA-d(6) and HQ-d(6) were used as internal standards (IS). The samples were extracted with methanol, dried under nitrogen and derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)+1% trimethylchlorosilane (TMCS). Quantification was performed in SIM mode with a limit of quantification (LOQ) of 50 ng ml(-1) for SA and 10 ng ml(-1) for HQ. The inter-day variation (R.S.D.) was less than 5% and the accuracy was better than 13.3% for both compounds. The recoveries from the different matrices ranged between 93.1 and 103.3% for SA, and 97.3 and 100.8% for HQ.
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Affiliation(s)
- Anja Judefeind
- School of Pharmacy, North-West University, Potchefstroom Campus, Potchefstroom 2520, South Africa
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Vincenti M, Biazzi S, Ghiglione N, Valsania MC, Richardson SD. Comparison of highly-fluorinated chloroformates as direct aqueous sample derivatizing agents for hydrophilic analytes and drinking-water disinfection by-products. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2005; 16:803-13. [PMID: 15907696 DOI: 10.1016/j.jasms.2005.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2004] [Revised: 02/01/2005] [Accepted: 02/02/2005] [Indexed: 05/02/2023]
Abstract
Four highly-fluorinated alkyl and aryl chloroformates, including 2,2,3,3,4,4,5,5-octafluoro-1-pentyl chloroformate (OFPCF), 2,3,4,5,6-pentafluorobenzyl chloroformate (PFBCF), 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-1-octyl chloroformate (TDFOCF), and 2-(2,3,4,5,6-pentafluorophenoxy)-ethyl chloroformate (PFPECF), were synthesized and tested as reagents for the direct water derivatization of polar and hydrophilic analytes. The goal of this research was to develop an optimal derivatizing agent to aid in the identification of highly polar ozonation drinking water disinfection by-products (DBPs) that are believed to be missed with current analytical procedures. The chemical properties (reactivity, selectivity, derivatization products, and their chromatographic and spectral features) for the four chloroformates were investigated using a set of highly polar standard analytes, including malic and tartaric acids, hydroxylamine, valine, 2-aminoethanol, resorcinol, 1,3,5-trihydroxybenzene, and 2,4-dihydroxybenzoic acid. Upon derivatization, the analytes were extracted from the aqueous solvent and analyzed by gas chromatography (GC)-mass spectrometry (MS) in the electron capture negative ionization (ECNI) mode. Positive chemical ionization (PCI)-MS was used for confirmation of molecular ions that were weak or absent in ECNI mass spectra. Of the four derivatizing reagents tested, OFPCF showed the best performance, with good reaction efficiency, good chromatographic and spectroscopic properties, low detection limits (10-100 fmol), and a linear response more than two orders of magnitude. Further, the entire procedure from raw aqueous sample to ready-to-inject hexane solutions of the derivatives requires less than 10 min. PFBCF showed ideal applicability for derivatizing aminoalcohols and aminoacids. The two chloroformates with the highest intrinsic stability (TDFOCF and PFPECF) failed to derivatize some of the analytes. Finally, the OFPCF derivatizing agent was tested with simulated ozonated drinking water (aqueous fulvic acid treated with ozone), and three highly polar reaction by-products were determined.
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Affiliation(s)
- Marco Vincenti
- Dipartimento di Chimica Analitica, Università di Torino, Via Pietro Giuria 5, 10125 Turin, Italy.
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Zaikin VG, Halket JM. Review: derivatization in mass spectrometry-6. Formation of mixed derivatives of polyfunctional compounds. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2005; 11:611-36. [PMID: 16322667 DOI: 10.1255/ejms.773] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The review describes chemical transformations of multifunctional compounds (amino acids and peptides, amino alcohols, amino thiols, hydroxy acids, oxo acids, oxo alcohols, compounds containing simultaneously three or more different groups etc.) by using step-wise or one-step modification or protection of functional groups. Some chemical aspects of mixed derivatization performed for improving the physical-chemical properties and mass spectral characteristics are discussed. Application of mixed derivatization to qualitative and quantitative analysis of various multifunctional compounds mainly in biological fluids and other matrices by gas chromatography/mass spectrometry in electron ionization, chemical ionization, negative-ion chemical ionization and selected ion monitoring modes is considered.
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Affiliation(s)
- Vladimir G Zaikin
- Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninsky prospect 29, 119991 Moscow, Russia.
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Black RM, Muir B. Derivatisation reactions in the chromatographic analysis of chemical warfare agents and their degradation products. J Chromatogr A 2003; 1000:253-81. [PMID: 12877174 DOI: 10.1016/s0021-9673(03)00183-3] [Citation(s) in RCA: 167] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The analysis of chemical warfare agents and their degradation products is an important component of verification of compliance with the Chemical Weapons Convention. Gas and liquid chromatography, particularly combined with mass spectrometry, are the major techniques used to detect and identify chemicals of concern to the Convention. The more polar analytes, and some of the more reactive or highly volatile agents, are usually derivatised to facilitate chromatography, and to impart properties beneficial for detection. This review focuses on derivatisation reactions used in the chromatographic analysis of chemical warfare agents, their degradation products and metabolites.
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Zaikin VG, Halket JM. Review: Derivatization in mass spectrometry--2. Acylation. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2003; 9:421-434. [PMID: 14624012 DOI: 10.1255/ejms.576] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The present review is devoted to acylation as a widely employed derivatization procedure for protection of OH (alcohols, polyols, phenols, enols), SH (thiols) and NH (amines, amides) groups in order to increase volatility, improve chromatographic properties and, if possible, improve mass spectral properties of derivatives. Chemical aspects of derivatization and various acylating agents are characterized. Mass spectral [electron ionization (EI), chemical ionization (CI) and negative-ion (NI) CI] properties of derivatives that are helpful in identification, structure elucidation and quantitative determination of the analyzed compounds are discussed. Some recent analytical applications of the procedure in synthetic organic chemistry, clinical chemistry, environmental chemistry etc. are summarized.
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Affiliation(s)
- Vladimir G Zaikin
- Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia.
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Henriksen T, Svensmark B, Lindhardt B, Juhler RK. Analysis of acidic pesticides using in situ derivatization with alkylchloroformate and solid-phase microextraction (SPME) for GC-MS. CHEMOSPHERE 2001; 44:1531-1539. [PMID: 11545518 DOI: 10.1016/s0045-6535(00)00532-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A solid-phase microextraction (SPME) method was developed for the analysis of acidic pesticide residues in water. The method utilizes in situ derivatization with butylchloroformate (BuCF), followed by on-line SPME extraction using a PDMS fibre, and analysis by GC-MS. Derivatives of the phenoxy acids mechlorprop (MCPP), dichlorprop (DCPP), MCPA and 2,4-D and their phenol degradation products 4-chloro-2-methylphenol and 2,4-dichlorophenol (DCP) were identified. Detection limits at 0.16-2.3 microg/l were achieved. Optimization of derivatization, ion strength, extraction time, SPME-fibre, desorption time and temperature are described. Standard curves in the range 0.5-10.0 microg/l were fitted to a second-degree polynomial. Standard deviation (n = 5) was below 10% for the phenol derivatives, but 20-50% for the phenoxy acids. For method verification groundwater samples from a field experiment were screened for content of MCPP and compared to the results from the HPLC analysis. A good agreement was obtained with respect to identification of positive samples, even though concentrations measured by the SPME were lower than with HPLC. Even if the precision and accuracy do not meet the demands for a strictly quantitative analysis, the SPME method is suitable for screening, because it is cheap, it can be automated, and uses smaller amounts of potential harmful solvents. Also, the method is less labour-intensive, as it requires a minimum of sample preparation when compared to traditional analyses. The acidic pesticides bentazon, dicamba, bromoxynil, ioxynil, dinoseb and DNOC were included in the study but could not be analysed by the current method.
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Affiliation(s)
- T Henriksen
- Department of Geochemistry, Geological Survey of Denmark and Greenland (GEUS), Copenhagen, Denmark.
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Determination of Gamma-hydroxybutyrate in Water and Human Urine by Solid Phase Microextraction-Gas Chromatography/Quadrupole Ion Trap Spectrometry. J Forensic Sci 2001. [DOI: 10.1520/jfs15023j] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Affiliation(s)
- S D Richardson
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Athens, Georgia 30605, USA
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Wittman GY, Van Langenhove H, Dewulf J. Determination of acetic acid in aqueous samples, by water-phase derivatisation, solid-phase microextraction and gas chromatography. J Chromatogr A 2000; 874:225-34. [PMID: 10817361 DOI: 10.1016/s0021-9673(00)00114-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The direct derivatisation of acetic acid with n-hexyl chloroformate and with benzyl bromide in water was evaluated. With n-hexyl chloroformate, acetic acid did not give the n-hexyl acetate derivative, but the reaction of acetic acid with benzyl bromide in aqueous solution resulted in the formation of benzyl acetate. The derivatisation of acetic acid with benzyl bromide and the headspace solid-phase microextraction (SPME) of benzyl acetate were optimised. Under optimum conditions, the limit of detection for acetic acid was 260 nM, and the relative standard deviation of the overall procedure at 1.10(-4) M acetic acid was 15.6% (n = 10). A linear response was obtained in the 1 x 10(-4) to 5 x 10(-6) M concentration range (R2 = 0.993, n = 6). Although Carbowax-divinylbenzene (CW-DVB)-coated fibres exhibited a higher extraction capacity for benzyl acetate, polyacrylate (PA) was selected, because its mechanical stability was better than that of CW-DVB fibres. Moreover, the relative standard deviation of the SPME was better with PA (1.5%, n = 10 at 1 x 10(-5) M) than with CW-DVB-coated fibres (8.0%, n = 10 at 1 x 10(-5) M). Thus, a new analytical method for the quantitative determination of micromolar concentrations of acetic acid in the aqueous phase was developed. This method is based on water-phase derivatisation with benzyl bromide, headspace SPME with PA fibres and GC-FID. It was observed experimentally that benzyl alcohol formed by hydrolysis of the reagent affected the fibre-gas phase partitioning of benzyl acetate.
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Affiliation(s)
- G Y Wittman
- Department of Inorganic and Analytical Chemistry, József Attila University, Szeged, Hungary.
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Aqueous Phase Hexylchloroformate Derivatization and Solid Phase Microextraction: Determination of Benzoylecgonnine in Urine by Gas Chromatography-Quadrupole Ion Trap Mass Spectrometry. J Forensic Sci 1999. [DOI: 10.1520/jfs14504j] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Improved procedure for n-hexyl chloroformate-mediated derivatization of highly hydrophilic substances directly in water: hydroxyaminic compounds. J Chromatogr A 1998. [DOI: 10.1016/s0021-9673(97)00911-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Affiliation(s)
- R E Clement
- Laboratory Services Branch, Ontario Ministry of Environment and Energy, Etobicoke, Canada
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Simpson JT, Torok DS, Markey SP. Pentafluorobenzyl chloroformate derivatization for enhancement of detection of amino acids or alcohols by electron capture negative ion chemical ionization mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 1995; 6:525-528. [PMID: 24214307 DOI: 10.1016/1044-0305(95)00231-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/1995] [Revised: 02/27/1995] [Accepted: 02/27/1995] [Indexed: 06/02/2023]
Abstract
Pentafluorobenzyl chloroformate (PFB-chloroformate) has been utilized as a derivatization reagent to impart electron affinity and provide structurally relevant fragmentation in electron capture negative ion chemical ionization mass spectrometry (ECNICI-MS). Phenylalanine (Phe) and decanol were used as model analytes. The conditions used for their derivatization and the chromatographic and mass spectrometric properties of the derivatives are reported. Phenylalanine in aqueous solution was derivatized in one step by using PFB-chloroformate and a mixture of water, ethanol, and pyridine. The phenylalanine N-pentafluorobenzyl-oxycarbonyl ethyl ester (N-PFBC-Phe-OEt) exhibited good gas chromatographic properties and in ECNICI-MS, a dominant [M - 181](-) fragment carries most of the ion current. Selected ion monitoring experiments on N-PFBC-Phe-OEt resulted in the facile detection of 400 fmol of material. Decanol was derivatized by using anhydrous conditions, and the resultant pentafluorobenzyl carbonate also exhibited a predominant [M - 181](-) ion in ECNICI-MS. Initial results indicate that the ECNICI-MS molar response of the decyl pentafluorobenzyl carbonate derivative is six-fold that of the decyl pentafluorobenzoate.
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Affiliation(s)
- J T Simpson
- Section on Analytical Biochemistry, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA
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