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Kevin A Schug - One of the best experts on this subject based on the ideXlab platform.
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continuous flow extractive desorption electrospray Ionization analysis from non electrospray Ionization friendly solvents and related mechanism
Analytica Chimica Acta, 2013Co-Authors: Li Li, Samuel H Yang, Karel Lemr, Vladimir Havlicek, Kevin A SchugAbstract:Abstract Due to their low polarities and dielectric constants, analytes in solvents such as hexane, chloroform, and ethyl acetate exhibit poor electrospray Ionization (ESI) efficiency. These are deemed to be “non-ESI-friendly” solvents. Continuous flow extractive desorption electrospray Ionization (CF-EDESI) is a novel ambient Ionization Technique that was recently developed in our group to manipulate protein charge distributions. Here we demonstrate its potential for ionizing analytes from non-ESI-friendly solvents. This feature makes CF-EDESI attractive to the general analytical community due to its apparent potential in lipidomics, normal phase separations, and hyphenation of mass spectrometry with HPLC-NMR systems. In this context, interest was subsequently initiated to discern mechanistic aspects of CF-EDESI. To achieve this, mechanistic experiments associated with a seemingly similar ambient Ionization Technique, extractive electrospray Ionization (EESI), were emulated to compare CF-EDESI and EESI. Analysis of a series of fatty acids in multiple solvents in the negative Ionization mode revealed differences between the two Techniques. Whereas EESI has been previously shown to operate via extraction of analytes into the spray solvent, data presented here for CF-EDESI point toward a liquid-liquid mixing process to facilitate Ionization. Further, a partial factorial design experiment was performed to evaluate the effects of different experimental variables on signal intensity. Sample flow rate was confirmed to be among the most significant factors to affect sensitivity. As a whole, the work presented provides greater insight into a new ambient Ionization process, which exhibits expanded capabilities over conventional ESI; in this case, for direct analysis from non-ESI-friendly solvents.
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manipulation of protein charge states through continuous flow extractive desorption electrospray Ionization a new ambient Ionization Technique
Analytical Chemistry, 2011Co-Authors: Samuel H Yang, Li Li, Aruna B Wijeratne, Brian L Edwards, Kevin A SchugAbstract:Manipulation of protein charge states in electrospray Ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein−protein interactions, post-translational modifications, and protein sequencing. Control of these protein charge states is often difficult to achieve with conventional methods of analysis. A novel ambient Ionization configuration, continuous flow-extractive desorption electrospray Ionization (CF-EDESI), is presented as a means to control the charge state distribution of proteins. A key feature of the CF-EDESI Technique is the continuous flow needle, which is a hypodermic needle presented orthogonal to the electrospray source and delivers a solvent flow containing analytes for extractive desorption Ionization. With this source design, the successful manipulation of cytochrome c and lysozyme charge states with the use of different additives, such as acetic acid and sulfolane, was demonstrated. Results were compared to data obtained with conventional electrospr...
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manipulation of protein charge states through continuous flow extractive desorption electrospray Ionization a new ambient Ionization Technique
Analytical Chemistry, 2011Co-Authors: Samuel H Yang, Aruna B Wijeratne, Brian L Edwards, Kevin A SchugAbstract:Manipulation of protein charge states in electrospray Ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein−protein interactions, post-translational modif...
Marcos N Eberlin - One of the best experts on this subject based on the ideXlab platform.
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venturi easy ambient sonic spray Ionization
Analytical Chemistry, 2011Co-Authors: Vanessa G Santos, Thais Regiani, Fernanda F G Dias, Wanderson Romao, Jose Luis Paz Jara, Clecio F Klitzke, Fernando Coelho, Marcos N EberlinAbstract:The development and illustrative applications of an ambient Ionization Technique termed Venturi easy ambient sonic-spray Ionization (V-EASI) is described. Its dual mode of operation with Venturi self-pumping makes V-EASI applicable to the direct mass spectrometric analysis of both liquid (VL-EASI) and solid (VS-EASI) samples. V-EASI is simple and easy to assemble, operating solely via the assistance of a sonic stream of nitrogen or air. The sonic gas stream causes two beneficial and integrated effects: (a) the self-pumping of solutions via the Venturi effect and (b) sonic-spray Ionization (SSI) of analytes either in solution or resting on solid surfaces. In its liquid mode, VL-EASI is applicable to analytes in solution, forming negatively and/or positively charged intact molecular species in a soft fashion with little or no fragmentation. In its solid mode, VS-EASI relies on Venturi self-pumping of a proper SSI solvent solution in combination with SSI to form a stream of bipolar charged droplets that bomb...
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perfume fingerprinting by easy ambient sonic spray Ionization mass spectrometry nearly instantaneous typification and counterfeit detection
Rapid Communications in Mass Spectrometry, 2008Co-Authors: Renato Haddad, Rodrigo Ramos Catharino, Lygia Azevedo Marques, Marcos N EberlinAbstract:Perfume counterfeiting is an illegal worldwide practice that involves huge economic losses and potential consumer risk. EASI is a simple, easily performed and rapidly implemented desorption/Ionization Technique for ambient mass spectrometry (MS). Herein we demonstrate that EASI-MS allows nearly instantaneous perfume typification and counterfeit detection. Samples are simply sprayed onto a glass rod or paper surface and, after a few seconds of ambient drying, a profile of the most polar components of the perfume is acquired. These components provide unique and reproducible chemical signatures for authentic perfume samples. Counterfeiting is readily recognized since the exact set and relative proportions of the more polar chemicals, sometimes at low concentrations, are unknown or hard to reproduce by the counterfeiters and hence very distinct and variable EASI-MS profiles are observed for the counterfeit samples. Copyright © 2008 John Wiley & Sons, Ltd.
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easy ambient sonic spray Ionization mass spectrometry combined with thin layer chromatography
Analytical Chemistry, 2008Co-Authors: Renato Haddad, Rodrigo Ramos Catharino, Humberto M S Milagre, Marcos N EberlinAbstract:On-spot detection and analyte characterization on thin-layer chromatography (TLC) plates is performed via ambient desorption/Ionization and (tandem) mass spectrometry detection, that is, via easy ambient sonic spray Ionization mass spectrometry (EASI-MS). As proof-of-principle cases, mixtures of semipolar nitrogenated compounds as well as pharmaceutical drugs and vegetable oils have been tested. The Technique has also been applied to monitor a chemical reaction of synthetic importance. EASI is the simplest and gentlest ambient Ionization Technique currently available, assisted solely by N2 (or air). It uses no voltages, no electrical discharges; no UV or laser beams, and no high temperature and is most easily implemented in all API mass spectrometers. TLC is also the simplest, fastest, and most easily performed chromatographic Technique. TLC plus EASI-MS therefore provide a simple and advantageous combination of chromatographic separation and sensitive detection of the TLC spots as well as on-spot MS or M...
Samuel H Yang - One of the best experts on this subject based on the ideXlab platform.
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continuous flow extractive desorption electrospray Ionization analysis from non electrospray Ionization friendly solvents and related mechanism
Analytica Chimica Acta, 2013Co-Authors: Li Li, Samuel H Yang, Karel Lemr, Vladimir Havlicek, Kevin A SchugAbstract:Abstract Due to their low polarities and dielectric constants, analytes in solvents such as hexane, chloroform, and ethyl acetate exhibit poor electrospray Ionization (ESI) efficiency. These are deemed to be “non-ESI-friendly” solvents. Continuous flow extractive desorption electrospray Ionization (CF-EDESI) is a novel ambient Ionization Technique that was recently developed in our group to manipulate protein charge distributions. Here we demonstrate its potential for ionizing analytes from non-ESI-friendly solvents. This feature makes CF-EDESI attractive to the general analytical community due to its apparent potential in lipidomics, normal phase separations, and hyphenation of mass spectrometry with HPLC-NMR systems. In this context, interest was subsequently initiated to discern mechanistic aspects of CF-EDESI. To achieve this, mechanistic experiments associated with a seemingly similar ambient Ionization Technique, extractive electrospray Ionization (EESI), were emulated to compare CF-EDESI and EESI. Analysis of a series of fatty acids in multiple solvents in the negative Ionization mode revealed differences between the two Techniques. Whereas EESI has been previously shown to operate via extraction of analytes into the spray solvent, data presented here for CF-EDESI point toward a liquid-liquid mixing process to facilitate Ionization. Further, a partial factorial design experiment was performed to evaluate the effects of different experimental variables on signal intensity. Sample flow rate was confirmed to be among the most significant factors to affect sensitivity. As a whole, the work presented provides greater insight into a new ambient Ionization process, which exhibits expanded capabilities over conventional ESI; in this case, for direct analysis from non-ESI-friendly solvents.
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manipulation of protein charge states through continuous flow extractive desorption electrospray Ionization a new ambient Ionization Technique
Analytical Chemistry, 2011Co-Authors: Samuel H Yang, Li Li, Aruna B Wijeratne, Brian L Edwards, Kevin A SchugAbstract:Manipulation of protein charge states in electrospray Ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein−protein interactions, post-translational modifications, and protein sequencing. Control of these protein charge states is often difficult to achieve with conventional methods of analysis. A novel ambient Ionization configuration, continuous flow-extractive desorption electrospray Ionization (CF-EDESI), is presented as a means to control the charge state distribution of proteins. A key feature of the CF-EDESI Technique is the continuous flow needle, which is a hypodermic needle presented orthogonal to the electrospray source and delivers a solvent flow containing analytes for extractive desorption Ionization. With this source design, the successful manipulation of cytochrome c and lysozyme charge states with the use of different additives, such as acetic acid and sulfolane, was demonstrated. Results were compared to data obtained with conventional electrospr...
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manipulation of protein charge states through continuous flow extractive desorption electrospray Ionization a new ambient Ionization Technique
Analytical Chemistry, 2011Co-Authors: Samuel H Yang, Aruna B Wijeratne, Brian L Edwards, Kevin A SchugAbstract:Manipulation of protein charge states in electrospray Ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein−protein interactions, post-translational modif...
Aruna B Wijeratne - One of the best experts on this subject based on the ideXlab platform.
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manipulation of protein charge states through continuous flow extractive desorption electrospray Ionization a new ambient Ionization Technique
Analytical Chemistry, 2011Co-Authors: Samuel H Yang, Li Li, Aruna B Wijeratne, Brian L Edwards, Kevin A SchugAbstract:Manipulation of protein charge states in electrospray Ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein−protein interactions, post-translational modifications, and protein sequencing. Control of these protein charge states is often difficult to achieve with conventional methods of analysis. A novel ambient Ionization configuration, continuous flow-extractive desorption electrospray Ionization (CF-EDESI), is presented as a means to control the charge state distribution of proteins. A key feature of the CF-EDESI Technique is the continuous flow needle, which is a hypodermic needle presented orthogonal to the electrospray source and delivers a solvent flow containing analytes for extractive desorption Ionization. With this source design, the successful manipulation of cytochrome c and lysozyme charge states with the use of different additives, such as acetic acid and sulfolane, was demonstrated. Results were compared to data obtained with conventional electrospr...
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manipulation of protein charge states through continuous flow extractive desorption electrospray Ionization a new ambient Ionization Technique
Analytical Chemistry, 2011Co-Authors: Samuel H Yang, Aruna B Wijeratne, Brian L Edwards, Kevin A SchugAbstract:Manipulation of protein charge states in electrospray Ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein−protein interactions, post-translational modif...
Li Li - One of the best experts on this subject based on the ideXlab platform.
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continuous flow extractive desorption electrospray Ionization analysis from non electrospray Ionization friendly solvents and related mechanism
Analytica Chimica Acta, 2013Co-Authors: Li Li, Samuel H Yang, Karel Lemr, Vladimir Havlicek, Kevin A SchugAbstract:Abstract Due to their low polarities and dielectric constants, analytes in solvents such as hexane, chloroform, and ethyl acetate exhibit poor electrospray Ionization (ESI) efficiency. These are deemed to be “non-ESI-friendly” solvents. Continuous flow extractive desorption electrospray Ionization (CF-EDESI) is a novel ambient Ionization Technique that was recently developed in our group to manipulate protein charge distributions. Here we demonstrate its potential for ionizing analytes from non-ESI-friendly solvents. This feature makes CF-EDESI attractive to the general analytical community due to its apparent potential in lipidomics, normal phase separations, and hyphenation of mass spectrometry with HPLC-NMR systems. In this context, interest was subsequently initiated to discern mechanistic aspects of CF-EDESI. To achieve this, mechanistic experiments associated with a seemingly similar ambient Ionization Technique, extractive electrospray Ionization (EESI), were emulated to compare CF-EDESI and EESI. Analysis of a series of fatty acids in multiple solvents in the negative Ionization mode revealed differences between the two Techniques. Whereas EESI has been previously shown to operate via extraction of analytes into the spray solvent, data presented here for CF-EDESI point toward a liquid-liquid mixing process to facilitate Ionization. Further, a partial factorial design experiment was performed to evaluate the effects of different experimental variables on signal intensity. Sample flow rate was confirmed to be among the most significant factors to affect sensitivity. As a whole, the work presented provides greater insight into a new ambient Ionization process, which exhibits expanded capabilities over conventional ESI; in this case, for direct analysis from non-ESI-friendly solvents.
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manipulation of protein charge states through continuous flow extractive desorption electrospray Ionization a new ambient Ionization Technique
Analytical Chemistry, 2011Co-Authors: Samuel H Yang, Li Li, Aruna B Wijeratne, Brian L Edwards, Kevin A SchugAbstract:Manipulation of protein charge states in electrospray Ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein−protein interactions, post-translational modifications, and protein sequencing. Control of these protein charge states is often difficult to achieve with conventional methods of analysis. A novel ambient Ionization configuration, continuous flow-extractive desorption electrospray Ionization (CF-EDESI), is presented as a means to control the charge state distribution of proteins. A key feature of the CF-EDESI Technique is the continuous flow needle, which is a hypodermic needle presented orthogonal to the electrospray source and delivers a solvent flow containing analytes for extractive desorption Ionization. With this source design, the successful manipulation of cytochrome c and lysozyme charge states with the use of different additives, such as acetic acid and sulfolane, was demonstrated. Results were compared to data obtained with conventional electrospr...