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Damia Barcelo - One of the best experts on this subject based on the ideXlab platform.
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determinatIon of haloacetic acids in aqueous environments by solid phase extractIon followed by Ion Pair liquid Chromatography electrospray IonizatIon mass spectrometric detectIon
Journal of Chromatography A, 2001Co-Authors: Robert Loos, Damia BarceloAbstract:Haloacetic acids (HAAs) were determined in different water samples by a new, fast and simple analysis method based on enrichment of 50-ml water samples at pH 1.8 by solid-phase extractIon (SPE) followed by liquid Chromatography (LC) separatIon and electrospray IonizatIon mass spectrometric detectIon in the negative IonizatIon mode. Deprotonated (M-H)− haloacetates and decarboxylated (M-COOH)− Ions were detected. Different polymeric SPE sorbents were tested, and LiChrolut EN was found to be the best material for the extractIon. Complete LC separatIon of all compounds could only be achieved by Ion-Pair Chromatography using triethylamine as volatile Ion-Pairing reagent. The detectIon limits were in the low μg/l range. High μg/l concentratIon levels for the chlorinated and brominated haloacetates were found in drinking water from a drinking water treatment plant in Barcelona, and the corresponding tap water. In swimming pool water samples from Catalonia mg/l levels and in surface river water from Portugal μg/l values were detected. These results confirm other recent reports on the ubiquitous occurrence of HAAs in aqueous environments.
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characterisatIon of organic pollutants in textile wastewaters and landfill leachate by using toxicity based fractIonatIon methods followed by liquid and gas Chromatography coupled to mass spectrometric detectIon
Analytica Chimica Acta, 2001Co-Authors: Monserrat Castillo, Damia BarceloAbstract:Abstract In the present work, the characterisatIon of toxic organic compounds present in complex mixtures like textile effluents and landfill leachates is proposed. The protocol developed for the wastewater characterisatIon is based on solid phase extractIon (SPE) combined with toxicity-fractIonatIon followed by high temperature-gas Chromatography-mass spectrometry (HT-GC-MS) and liquid Chromatography-mass spectrometry (LC-MS). In this work Daphnia magna was used as the target organism to identify the toxic compounds in the different fractIons. The highest toxicity was observed in the fractIons exhibiting log K ow (octanol–water partitIon coefficient) between 1.7 and 5.16. After SPE followed by GC-MS and LC-MS using atmospheric pressure chemical IonisatIon (APCI) the compounds identified in the more toxic fractIons were bis(2-ethylhexyl)phthalate, dibutyl phthalate, alcohol decyclic alcohol polyethoxylated, disulphonate hydoxynaphthalene, nonylphenol polyethoxylated and nonylphenol isomers. In additIon to the toxicity based fractIonatIon, a sequential solid phase extractIon protocol (SSPE) followed by LC-APCI-MS, LC-electrospray (ESI)-MS and Ion-Pair Chromatography (IPC)-ESI-MS) was also applied to the raw samples in order to identify the major number of polar organic pollutants.
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tracing polar benzene and naphthalenesulfonates in untreated industrial effluents and water treatment works by Ion Pair Chromatography fluorescence and electrospray mass spectrometry
Analytica Chimica Acta, 1999Co-Authors: M C Alonso, Damia BarceloAbstract:Abstract This paper presents a protocol for the determinatIon of a class of polar, Ionic and highly water-soluble organic pollutants: benzene- and naphthalenesulfonic acids, compounds widely used in chemical, pharmaceutical, tannery, paper and textile industries. This protocol involves the use of a solid-phase extractIon (SPE) followed by Ion-Pair Chromatography-electrospray-mass spectrometry (IPC-ESI-MS). In this work two polymeric solid-phase extractIon cartridges (Isolute ENV+ and Lichrolut EN) were compared, with the more effective being Isolute ENV+ sorbent. Recoveries and breakthrough volumes were calculated by loading volumes of 150, 200 and 300 ml of spiked ground water through the SPE columns. To enhance the effectiveness of the methodology, 1 ml of water containing 5 mM TEA was added before eluting with methanol. Average recoveries ranging from 70 to 100% were obtained for a variety of 13 analytes (only two naphthalenesulfonate compounds had recoveries below 50%.). DeterminatIon of benzene- and naphthalenesulfonates was accomplished by Ion-Pair Chromatography-fluorescence detectIon (IPC-FLD). The ESI-MS parameters were optimized to achieve maximum sensitivity. [M–H]− Ion was the base peak using low energies (fragmentor voltage: 80 V). Significant fragmentatIon of the quasi-molecular [M–H]− Ion occurs at higher fragmentor voltages, leading to [M–SO2H]−, [M–SO3H]− and [SO3]− as diagnostic Ions, but with some sensitivity losses (more than two orders of magnitude when 150 V are applied as fragmentor voltage). CollisIon-induced dissociatIon (CID) of the parent Ions for the benzene- and naphthalenesulfonates studied gave the [SO3]− fragment Ion common to sulfonated compounds, it has been shown to be characteristic of aromatic sulfonated compounds and could be used as a diagnostic tool to indicate the presence of these compounds. Limits of detectIon (signal-to-noise ratio = 3) ranging from 0.03 pg to 0.05 ng, were achieved when 150 ml of ground water were processed and quantified by IPC-FLD. In IPC-ESI-MS, time-scheduled SIM mode with post-column additIon of 0.2 m min−1 of methanol was used. LODs range from 0.6 pg to 0.13 ng. In summary, with the development of a methodology based on SPE followed by IPC-ESI-MS, good sensitivity, structural informatIon and unequivocal identificatIon can be achieved. This protocol was applied to the analysis of surface waters, untreated industrial waste waters and wastewater treatment works effluents and influents. In the case of tannery effluent samples, isomers of naphthalenesulfonic acid were found as major pollutants in concentratIons up to 0.8 and 1.0 mg l−1, for 1-naphthalenesulfonate and 2-naphthalenesulfonate, respectively. The main contaminants in wastewater treatment work samples were 2,6-naphthalenedisulfonate, 1-hydroxy-3,6-naphthalenedisulfonate, 3-nitrobenzenesulfonate, 1-naphthalenesulfonate and 2-naphthalenesulfonate, with levels of ug/l.
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solid phase extractIon procedure of polar benzene and naphthalenesulfonates in industrial effluents followed by unequivocal determinatIon with Ion Pair Chromatography electrospray mass spectrometry
Analytical Chemistry, 1999Co-Authors: M C Alonso, Montserrat Castillo, Damia BarceloAbstract:Highly water soluble benzene- and naphthalenesulfonates are widely used in the chemical, pharmaceutical, tannery, paper, and textile industries. In this work, Isolute ENV+ polystyrene divinylbenzene sorbent was used for the enrichment of 14 benzene- and naphthalenesulfonates from industrial wastewaters. The elutIon step was performed by adding 1 mL of water containing Ion-Pair reagent (5 mM of triethylamine (TEA) and 5 mM of acetic acid at pH 6.5) and 9 mL of methanol at 1 mL/min. The most relevant contributIon was the use of Ion-Pair liquid Chromatography followed by an orthogonal electrospray interface coupled to mass spectrometry in the negative IonizatIon mode with postcolumn additIon at 0.2 mL/min of methanol in combinatIon with a volatile substance (triethylamine) as an Ion-Pair reagent. [M−H]- Ion was the base peak using low fragmentor voltages of 80 V with the electrospray interface. Significant fragmentatIon of the quasimolecular [M−H]- Ion occurs at high fragmentor voltage, producing [M−SO2H]-, ...
Horst Thiermann - One of the best experts on this subject based on the ideXlab platform.
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reversed phase Ion Pair Chromatography diode array detectIon of the bispyridinium compound mb327 plasma analysis of a potential novel antidote for the treatment of organophosphorus poisoning
Drug Testing and Analysis, 2016Co-Authors: Harald John, Franz Worek, John Mikler, Horst ThiermannAbstract:In the case of poisoning by organophosphorus nerve agents or pesticides, there is still a lack of pharmacological treatment of the cholinergic crisis selectively targeting the nicotinic acetylcholine receptor. Recently, the compound MB327 was identified as a potential novel lead structure to close this gap, thus demanding a quantitative assay for initial pharmacokinetic (PK) studies. MB327 is a salt consisting of the dicatIonic bispyridinium compound (BPC) 1,1´-(propane-1,3-diyl)bis(4-tert-butylpyridinium) and two iodide counter Ions. Due to the permanent positive charge of the BPC, an isocratic reversed-phase Ion-Pair chromatographic separatIon (RPIPC) was developed using heptanesulfonic acid as Ion-Pairing reagent and 45% v/v methanol as organic modifier (1 mL/min). Selective UV-detectIon (230 nm) was done by a diode array detector (DAD) for reliable, rugged, precise (RSD < 7%) and accurate (96–104%) quantitative analysis of 50 μL swine plasma (linear range 1–1000 µg BPC/mL plasma, lower limit of quantificatIon 2 µg/mL). During method validatIon, diverse parameters essential for the chromatographic process were investigated to generate van´t Hoff, van Deemter and width plots allowing calculatIon of thermodynamic data like the distributIon constant K (5.7 ± 0.3), change in enthalpy, ΔH0: −23.66 kJ/mol, and entropy, ΔS0: −65 J/(mol*K). In additIon, RPIPC-DAD analysis enabled calculatIon of molar absorptivities of the BPC, e230: 17 400 ± 1100 L/(mol*cm), and iodide, e230: 9900 ± 400 L/(mol*cm), which determinatIon was hampered by interference with each other in conventIonal cuvette UV-spectrophotometric measurements. Finally, the RPIPC-DAD procedure was applied to samples from an in vivo study of swine. Copyright © 2015 John Wiley & Sons, Ltd.
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quantificatIon of pralidoxime 2 pam in urine by Ion Pair Chromatography diode array detectIon applicatIon to in vivo samples from minipig
Drug Testing and Analysis, 2012Co-Authors: Harald John, Michael Eddleston, Eddie R Clutton, Franz Worek, Horst ThiermannAbstract:Pralidoxime (2-PAM) is a monopyridinium oxime used as an antidote for the treatment of poisoning with organophosphorus (OP) compounds, for example, pesticides and nerve agents, reactivating OP-inhibited acetylcholinesterase. However, appropriate dosing and efficacy remains a matter of discussIon requiring experimental data. Therefore, we developed and validated an Ion Pair Chromatography-diode array detectIon (IPC-DAD) method suitable for quantitative analysis of 2-PAM in human and porcine urine. Before injectIon of 20 µl, urine was acidified with trichloroacetic acid, mixed with internal standard (pyridine-4-aldoxime, 4-PAO), and diluted with IPC solvent yielding a total dilutIon of 1:49.5 and a 100% recovery. Isocratic separatIon was carried out at 25 °C on a LiChrospher 60 RP-select B column (125 x 4.0 mm I.D.) using phosphate buffer (7.5 mM Na2HPO4, 7.5 mM KH2PO4, pH 2.6) mixed with octanesulfonate (2.5 mM) as Ion Pair reagent and acetonitrile (6% v/v) as organic modifier (1 ml/min). 2-PAM was detected at 293 nm and 4-PAO at 275 nm. The method is rugged, selective, and characterized by good intra-day and inter-day precisIon (RSD, 1.3–6.0%) and accuracy (88–100%) with a limit of detectIon at 4.9 µg/ml, a limit of quantificatIon at 9.8 µg/ml, and a broad calibratIon range from 4.9–2500 µg/ml. The procedure was applied to urine samples obtained from dimethoate poisoned minipigs receiving 2-PAM therapy (intravenous bolus injectIon and infusIon). Results indicate that 60–80% of infused 2-PAM is rapidly (within 1–2 h) excreted in the urine. Copyright © 2011 John Wiley & Sons, Ltd.
M T Galceran - One of the best experts on this subject based on the ideXlab platform.
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on line Ion Pair solid phase extractIon liquid Chromatography mass spectrometry for the analysis of quaternary ammonium herbicides
Journal of Chromatography A, 2000Co-Authors: R Castro, Encarnacion Moyano, M T GalceranAbstract:An Ion-Pair on-line solid-phase extractIon procedure using C8 extractIon disks, suitable for liquid Chromatography-mass spectrometry analysis is developed to determine quaternary ammonium herbicides (quats) in water samples. The separatIon of these compounds was performed using Ion-Pair Chromatography with heptafluorobutyric acid (15 mM, pH 3.3) and acetonitrile gradient elutIon. DetectIon was carried out using a quadrupole mass spectrometer. Water sample volumes up to 50 ml can be preconcentrated with recoveries higher than 70%. Good precisIon and accuracy (day-to-day and run-to-run) were obtained and the detectIon limits ranged from 6 to 85 ng l(-1). The proposed on-line Ion-Pair solid-phase method enables compliance with European Community directives for drinking waters (100 ng l(-1)).
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Ion Pair liquid Chromatography atmospheric pressure IonizatIon mass spectrometry for the determinatIon of quaternary ammonium herbicides
Journal of Chromatography A, 1999Co-Authors: R Castro, Encarnacion Moyano, M T GalceranAbstract:Abstract High-performance liquid Chromatography coupled with atmospheric pressure IonizatIon mass spectrometry (electrospray and atmospheric pressure chemical IonizatIon) has been used to characterize some quaternary ammonium herbicides (quats). The separatIon of these compounds was carried out using Ion-Pair Chromatography with heptafluorobutyric acid (15 mM, pH 3.3) and acetonitrile gradient elutIon for successful coupling to mass spectrometry. DetectIon limits down to 0.1–4 μg l−1 were obtained for spiked tap water following a preconcentratIon step. Good reproducibilities (day-to-day and run-to-run) were also obtained.
Harald John - One of the best experts on this subject based on the ideXlab platform.
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reversed phase Ion Pair Chromatography diode array detectIon of the bispyridinium compound mb327 plasma analysis of a potential novel antidote for the treatment of organophosphorus poisoning
Drug Testing and Analysis, 2016Co-Authors: Harald John, Franz Worek, John Mikler, Horst ThiermannAbstract:In the case of poisoning by organophosphorus nerve agents or pesticides, there is still a lack of pharmacological treatment of the cholinergic crisis selectively targeting the nicotinic acetylcholine receptor. Recently, the compound MB327 was identified as a potential novel lead structure to close this gap, thus demanding a quantitative assay for initial pharmacokinetic (PK) studies. MB327 is a salt consisting of the dicatIonic bispyridinium compound (BPC) 1,1´-(propane-1,3-diyl)bis(4-tert-butylpyridinium) and two iodide counter Ions. Due to the permanent positive charge of the BPC, an isocratic reversed-phase Ion-Pair chromatographic separatIon (RPIPC) was developed using heptanesulfonic acid as Ion-Pairing reagent and 45% v/v methanol as organic modifier (1 mL/min). Selective UV-detectIon (230 nm) was done by a diode array detector (DAD) for reliable, rugged, precise (RSD < 7%) and accurate (96–104%) quantitative analysis of 50 μL swine plasma (linear range 1–1000 µg BPC/mL plasma, lower limit of quantificatIon 2 µg/mL). During method validatIon, diverse parameters essential for the chromatographic process were investigated to generate van´t Hoff, van Deemter and width plots allowing calculatIon of thermodynamic data like the distributIon constant K (5.7 ± 0.3), change in enthalpy, ΔH0: −23.66 kJ/mol, and entropy, ΔS0: −65 J/(mol*K). In additIon, RPIPC-DAD analysis enabled calculatIon of molar absorptivities of the BPC, e230: 17 400 ± 1100 L/(mol*cm), and iodide, e230: 9900 ± 400 L/(mol*cm), which determinatIon was hampered by interference with each other in conventIonal cuvette UV-spectrophotometric measurements. Finally, the RPIPC-DAD procedure was applied to samples from an in vivo study of swine. Copyright © 2015 John Wiley & Sons, Ltd.
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quantificatIon of pralidoxime 2 pam in urine by Ion Pair Chromatography diode array detectIon applicatIon to in vivo samples from minipig
Drug Testing and Analysis, 2012Co-Authors: Harald John, Michael Eddleston, Eddie R Clutton, Franz Worek, Horst ThiermannAbstract:Pralidoxime (2-PAM) is a monopyridinium oxime used as an antidote for the treatment of poisoning with organophosphorus (OP) compounds, for example, pesticides and nerve agents, reactivating OP-inhibited acetylcholinesterase. However, appropriate dosing and efficacy remains a matter of discussIon requiring experimental data. Therefore, we developed and validated an Ion Pair Chromatography-diode array detectIon (IPC-DAD) method suitable for quantitative analysis of 2-PAM in human and porcine urine. Before injectIon of 20 µl, urine was acidified with trichloroacetic acid, mixed with internal standard (pyridine-4-aldoxime, 4-PAO), and diluted with IPC solvent yielding a total dilutIon of 1:49.5 and a 100% recovery. Isocratic separatIon was carried out at 25 °C on a LiChrospher 60 RP-select B column (125 x 4.0 mm I.D.) using phosphate buffer (7.5 mM Na2HPO4, 7.5 mM KH2PO4, pH 2.6) mixed with octanesulfonate (2.5 mM) as Ion Pair reagent and acetonitrile (6% v/v) as organic modifier (1 ml/min). 2-PAM was detected at 293 nm and 4-PAO at 275 nm. The method is rugged, selective, and characterized by good intra-day and inter-day precisIon (RSD, 1.3–6.0%) and accuracy (88–100%) with a limit of detectIon at 4.9 µg/ml, a limit of quantificatIon at 9.8 µg/ml, and a broad calibratIon range from 4.9–2500 µg/ml. The procedure was applied to urine samples obtained from dimethoate poisoned minipigs receiving 2-PAM therapy (intravenous bolus injectIon and infusIon). Results indicate that 60–80% of infused 2-PAM is rapidly (within 1–2 h) excreted in the urine. Copyright © 2011 John Wiley & Sons, Ltd.
R Castro - One of the best experts on this subject based on the ideXlab platform.
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on line Ion Pair solid phase extractIon liquid Chromatography mass spectrometry for the analysis of quaternary ammonium herbicides
Journal of Chromatography A, 2000Co-Authors: R Castro, Encarnacion Moyano, M T GalceranAbstract:An Ion-Pair on-line solid-phase extractIon procedure using C8 extractIon disks, suitable for liquid Chromatography-mass spectrometry analysis is developed to determine quaternary ammonium herbicides (quats) in water samples. The separatIon of these compounds was performed using Ion-Pair Chromatography with heptafluorobutyric acid (15 mM, pH 3.3) and acetonitrile gradient elutIon. DetectIon was carried out using a quadrupole mass spectrometer. Water sample volumes up to 50 ml can be preconcentrated with recoveries higher than 70%. Good precisIon and accuracy (day-to-day and run-to-run) were obtained and the detectIon limits ranged from 6 to 85 ng l(-1). The proposed on-line Ion-Pair solid-phase method enables compliance with European Community directives for drinking waters (100 ng l(-1)).
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Ion Pair liquid Chromatography atmospheric pressure IonizatIon mass spectrometry for the determinatIon of quaternary ammonium herbicides
Journal of Chromatography A, 1999Co-Authors: R Castro, Encarnacion Moyano, M T GalceranAbstract:Abstract High-performance liquid Chromatography coupled with atmospheric pressure IonizatIon mass spectrometry (electrospray and atmospheric pressure chemical IonizatIon) has been used to characterize some quaternary ammonium herbicides (quats). The separatIon of these compounds was carried out using Ion-Pair Chromatography with heptafluorobutyric acid (15 mM, pH 3.3) and acetonitrile gradient elutIon for successful coupling to mass spectrometry. DetectIon limits down to 0.1–4 μg l−1 were obtained for spiked tap water following a preconcentratIon step. Good reproducibilities (day-to-day and run-to-run) were also obtained.
