David Kane - Academia.edu (original) (raw)
Papers by David Kane
Aerosol Science and Technology, 2016
Our objective was to evaluate the suitability of using a capillary aerosol generator (CAG) instea... more Our objective was to evaluate the suitability of using a capillary aerosol generator (CAG) instead of using e-cigarette devices in 90-day or longer inhalation studies. Aerosol characteristics for both the CAG (which uses heat to produce a condensation aerosol) and e-cigarette generators have been previously reported, but a side-by-side comparison with the identical formulation has not been reported. Aerosols from both devices were analyzed immediately after generation for chemicals in the formulation (propylene glycol [PG], glycerin, water, and nicotine), selected carbonyls (acetaldehyde, acrolein, and formaldehyde) by ultra-performance liquid chromatography with ultraviolet detection (UPLC-UV), and a chemical fingerprint analysis using gas chromatographymass spectroscopy (GC-MS). Aerosol capture methods for chemical analysis included Cambridge filter pads or two impingers in series each containing solution to trap and stabilize selected carbonyl compounds. Particle size distribution (cascade impactor) and exposure port uniformity (gravimetric) was measured in four rodent inhalation exposure chambers under inhalation study conditions. The aerosol of both generators contained the same known and unknown chemicals. Similar levels of compounds in the formula except for PG were detected in the aerosol of both generators. CAG produced more consistent particulate aerosol than e-cigarette generator and had lower levels of carbonyls primarily due to lower levels of formaldehyde. Exposure port concentrations were consistent and closer to target values with the CAG compared to the e-cigarette aerosol generator. CAG was easier to operate on a daily basis although more difficult to maintain because it required daily cleaning compared to single-use e-cigarettes. CAG was determined to be suitable for use in 90-day or longer inhalation studies.
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2018
Dosimetry models can be used to predict the dose of inhaled material, but they require several pa... more Dosimetry models can be used to predict the dose of inhaled material, but they require several parameters including particle size distribution. The reported particle size distributions for aerosols from electronic nicotine delivery system (ENDS) products vary widely and don't always identify a specific product. A low-flow cascade impactor was used to determine the particle size distribution [mass median aerodynamic diameter (MMAD); geometric standard deviation (GSD)] from 20 different cartridge based ENDS products. To assess losses and vapor phase amount, collection efficiency of the system was measured by comparing the collected mass in the impactor to the difference in ENDS product mass. The levels of nicotine, glycerin, propylene glycol, water, and menthol in the formulations of each product were also measured. Regardless of the ENDS product formulation, the MMAD of all tested products was similar and ranged from 0.9 to 1.2 μm with a GSD ranging from 1.7 to 2.2. There was no ...
The Journal of Physical Chemistry
... M. Samy El-Shall,' W. Slack, W. Vann, D. &ne, and D. Hanley Departme... more ... M. Samy El-Shall,' W. Slack, W. Vann, D. &ne, and D. Hanley Department of ... peaks of the nanoscale anatase phase of Ti02 (the low temperature phase).I6J7 The Raman line at 144 cm-I is the most intense line in the Raman spectrum of the anatase natural crystal,I7 and ...
AIP Conference Proceedings, 2000
Two limiting regimes of ion induced nucleation kinetics are discussed. Analytical expressions for... more Two limiting regimes of ion induced nucleation kinetics are discussed. Analytical expressions for the nucleation rate are obtained. The influence of the molecular nature of the ion on the nucleation rate is shown. Experimental evidence of the limiting regimes is presented.
A new technique has been developed to study the role of molecular properties in the ion nucleatio... more A new technique has been developed to study the role of molecular properties in the ion nucleation of supersaturated vapors. The method uses resonance enhanced multiphoton ionization (REMPI), to selectively ionize a chromophore present at low concentrations (mole fractions of < 10-3) in a steady-state supersaturated vapor produced in a diffusion cloud chamber (DCC). The combination of REMPI and the
Analytical Chemistry, Jun 1, 2001
Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and gen... more Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and generate tens of thousands of spectra from typical measurement campaigns. The ART-2a spectrum algorithm has been used to classify these spectra. In this work, we generate a range of particles that are models of those that are common in the atmosphere. A single-particle mass spectrometer is used to analyze these known particles, and the spectra are classified using ART-2a. The optimum vigilance parameter is ∼0.5 while the optimum learning rate is ∼0.05. The classifications elucidate limitations in generation of test particles, their analysis by single-particle techniques, and their classification by ART-2a.
Inhalation Toxicology, Sep 23, 2009
Cigarette mainstream smoke (MS) is a dynamic aerosol consisting of a gas-vapor phase and a partic... more Cigarette mainstream smoke (MS) is a dynamic aerosol consisting of a gas-vapor phase and a particulate phase. In recent years, novel in vitro whole smoke exposure systems have been developed to expose cells directly to whole MS. One such system is the Burghart Mimic Smoker-01 (MSB-01). Our previous data using the MSB-01 indicated that a 50 ± 10% loss of particulate matter occurred prior to MS delivery into the exposure chamber. Additionally, a change in aerosol particle diameter was also measured, suggesting that the chemical composition of MS might be changing within the system. In this study, we have expanded on our previous work and compared the particulate phase chemical composition of undiluted and diluted MS generated by the instrument and that of the MS delivered into the exposure chamber. The average percent delivery of cigarette smoke condensate (CSC) detected for all the measured chemical constituents was 35 ± 13% for undiluted MS and 23 ± 8% for 1:1 diluted MS. The data also indicate that under our experimental conditions, incomplete mixing of the freshly generated MS occurs during its dilution by the system. Taken together, the data presented here show that significant chemical changes occur between the generation of MS by the system and its delivery into the exposure chamber. This indicates that due to the dynamic nature of cigarette smoke, it is important to characterize the exposure conditions in order to gain the best insight and accurately correlate exposure with biological endpoints.
Environmental Science Technology, 2000
The Journal of Physical Chemistry, 1995
... to the Thomas F. and Kate Miller Jeffress Memorial Trust (5-302), and to the Exxon Education ... more ... to the Thomas F. and Kate Miller Jeffress Memorial Trust (5-302), and to the Exxon Education Foundation for the partial support of this research. References and Notes (1) Wilson, C. R. SOC. London. Philos. Trans. A 1989, 193, 289. (2) Loeb, LB; Kipp, AF; Einarson, AW J. Chem ...
Nucleation and Atmospheric Aerosols 1996, 1996
The Journal of Physical Chemistry A, 2000
... El-Shall*. Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 2328... more ... El-Shall*. Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006. J. Phys. Chem. A , 2000, 104 (21), pp 49124919. DOI: 10.1021/jp991934g. Publication Date (Web): May 6, 2000. Copyright © 2000 American Chemical Society. Abstract. ...
The Journal of Chemical Physics, 1999
Recent measurements of critical supersaturations for the vapor phase homogeneous nucleation of se... more Recent measurements of critical supersaturations for the vapor phase homogeneous nucleation of several substances using a diffusion cloud chamber technique exhibit a dependence on the pressure of the carrier gas used in the experiments. A model of droplet growth and motion in a diffusion cloud chamber, combined with the density and temperature profiles of the chamber is presented to explain the pressure dependent results. The model demonstrates that at higher carrier gas pressures the growth of the droplets is retarded and the optical scattering signal from the particles is reduced. It is concluded that the observed effect may not result from a pressure dependence of the nucleation rate, but from a pressure dependence of the droplet growth and motion.
The Journal of Chemical Physics, 2005
A general solution for the steady-state ion-induced nucleation kinetics has been derived, conside... more A general solution for the steady-state ion-induced nucleation kinetics has been derived, considering the differences between ion-induced nucleation and homogeneous nucleation. This solution includes a new effect for nucleation kinetics, the interaction of charged clusters with vapor molecules. Analytical expressions for the ion-induced nucleation rate have been obtained for the limiting cases of high and low thermodynamic barriers. The physical explanation of the so-called sign effect is proposed based on multipole expansion of an electric field of the cluster ion. This theory gives good agreement with experiments and is used to elucidate experimentally observed phenomena.
Inhalation Toxicology, 2009
It is known that puffing conditions such as puff volume, duration, and frequency vary substantial... more It is known that puffing conditions such as puff volume, duration, and frequency vary substantially among individual smokers. This study investigates how these parameters affect the particle size distribution and concentration of fresh mainstream cigarette smoke (MCS) and how these changes affect the predicted deposition of MCS particles in a model human respiratory tract. Measurements of the particle size distribution made with an electrical low pressure impactor for a variety of puffing conditions are presented. The average flow rate of the puff is found to be the major factor effecting the measured particle size distribution of the MCS. The results of these measurements were then used as input to a deterministic dosimetry model (MPPD) to estimate the changes in the respiratory tract deposition fraction of smoke particles. The MPPD dosimetry model was modified by incorporating mechanisms involved in respiratory tract deposition of MCS: hygroscopic growth, coagulation, evaporation of semivolatiles, and mixing of the smoke with inhaled dilution air. The addition of these mechanisms to MPPD resulted in reasonable agreement between predicted airway deposition and human smoke retention measurements. The modified MPPD model predicts a modest 10% drop in the total deposition efficiency in a model human respiratory tract as the puff flow rate is increased from 1050 to 3100 ml/min, for a 2-s puff.
Inhalation Toxicology, 2009
In vitro systems are frequently used to study mechanisms of mainstream cigarette smoke (MS)induce... more In vitro systems are frequently used to study mechanisms of mainstream cigarette smoke (MS)induced lung injury. Traditional methods of exposure involve the capture of MS particulate phase with filter pads or bubbling MS through phosphate buffered saline (PBS) or cell culture medium. Although useful for in vitro experiments, these exposure methods may fail to capture potential interactions between the gas and particulate phases. To better understand the effect of MS on the human airway, in vitro whole smoke exposure systems that utilize freshly generated whole smoke are needed. Here we report the characterization of a new in vitro whole smoke exposure system (Burghart Mimic Smoker-01 (MSB-01)). This system uses a smoke distribution manifold to simultaneously deliver MS to each well of a 96-well plate. Intraday and interday variations for particulate matter deposition were less than 5% and 13% respectively. Cytotoxicity measurements using lung epithelial BEAS-2B cells indicate variations in calculated EC 50 (half maximal effective concentration) values of 13% intraday and 20% interday. Smoke particulate losses and changes in particle size distribution were also analyzed. The data indicate that 45-50% of the MS generated at the smoking ports is lost within the system prior to delivery into the exposure chamber; however, no changes in particle size distribution were detected throughout the system. Overall, the MSB-01 reproducibly delivered mainstream cigarette smoke in a dose dependent manner across the multiwell plate. The MSB-01 is a high throughput system capable of exposing cells to both the MS particulate and gas/vapor phases simultaneously.
Environmental Science & Technology, 2000
Chemical Physics Letters, 1997
ABSTRACT
Chemical Physics Letters, 1996
Resonance enhanced multiphoton ionization (REMPI) of aromatic molecules present in a small concen... more Resonance enhanced multiphoton ionization (REMPI) of aromatic molecules present in a small concentration within a supersaturated host vapor is demonstrated. The method is applied to the study of ion nucleation in supersaturated vapors of methanol, acetoniWile and nonane induced by the molecular ions of benzene, toluene, and p-xylene. With this method it is now possible to selectively and unambiguously generate specific ions of interest and study their nucleating behavior. Furthermore, the selectivity of REMPI combined with the amplification and detection capabilities of nucleation and growth offer valuable analytical features for the identification of trace components in supersaturated vapors.
Analytical Chemistry, 2001
Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and gen... more Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and generate tens of thousands of spectra from typical measurement campaigns. The ART-2a spectrum algorithm has been used to classify these spectra. In this work, we generate a range of particles that are models of those that are common in the atmosphere. A single-particle mass spectrometer is used to analyze these known particles, and the spectra are classified using ART-2a. The optimum vigilance parameter is ∼0.5 while the optimum learning rate is ∼0.05. The classifications elucidate limitations in generation of test particles, their analysis by single-particle techniques, and their classification by ART-2a.
Aerosol Science and Technology, 2016
Our objective was to evaluate the suitability of using a capillary aerosol generator (CAG) instea... more Our objective was to evaluate the suitability of using a capillary aerosol generator (CAG) instead of using e-cigarette devices in 90-day or longer inhalation studies. Aerosol characteristics for both the CAG (which uses heat to produce a condensation aerosol) and e-cigarette generators have been previously reported, but a side-by-side comparison with the identical formulation has not been reported. Aerosols from both devices were analyzed immediately after generation for chemicals in the formulation (propylene glycol [PG], glycerin, water, and nicotine), selected carbonyls (acetaldehyde, acrolein, and formaldehyde) by ultra-performance liquid chromatography with ultraviolet detection (UPLC-UV), and a chemical fingerprint analysis using gas chromatographymass spectroscopy (GC-MS). Aerosol capture methods for chemical analysis included Cambridge filter pads or two impingers in series each containing solution to trap and stabilize selected carbonyl compounds. Particle size distribution (cascade impactor) and exposure port uniformity (gravimetric) was measured in four rodent inhalation exposure chambers under inhalation study conditions. The aerosol of both generators contained the same known and unknown chemicals. Similar levels of compounds in the formula except for PG were detected in the aerosol of both generators. CAG produced more consistent particulate aerosol than e-cigarette generator and had lower levels of carbonyls primarily due to lower levels of formaldehyde. Exposure port concentrations were consistent and closer to target values with the CAG compared to the e-cigarette aerosol generator. CAG was easier to operate on a daily basis although more difficult to maintain because it required daily cleaning compared to single-use e-cigarettes. CAG was determined to be suitable for use in 90-day or longer inhalation studies.
Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association, 2018
Dosimetry models can be used to predict the dose of inhaled material, but they require several pa... more Dosimetry models can be used to predict the dose of inhaled material, but they require several parameters including particle size distribution. The reported particle size distributions for aerosols from electronic nicotine delivery system (ENDS) products vary widely and don't always identify a specific product. A low-flow cascade impactor was used to determine the particle size distribution [mass median aerodynamic diameter (MMAD); geometric standard deviation (GSD)] from 20 different cartridge based ENDS products. To assess losses and vapor phase amount, collection efficiency of the system was measured by comparing the collected mass in the impactor to the difference in ENDS product mass. The levels of nicotine, glycerin, propylene glycol, water, and menthol in the formulations of each product were also measured. Regardless of the ENDS product formulation, the MMAD of all tested products was similar and ranged from 0.9 to 1.2 μm with a GSD ranging from 1.7 to 2.2. There was no ...
The Journal of Physical Chemistry
... M. Samy El-Shall,' W. Slack, W. Vann, D. &ne, and D. Hanley Departme... more ... M. Samy El-Shall,' W. Slack, W. Vann, D. &ne, and D. Hanley Department of ... peaks of the nanoscale anatase phase of Ti02 (the low temperature phase).I6J7 The Raman line at 144 cm-I is the most intense line in the Raman spectrum of the anatase natural crystal,I7 and ...
AIP Conference Proceedings, 2000
Two limiting regimes of ion induced nucleation kinetics are discussed. Analytical expressions for... more Two limiting regimes of ion induced nucleation kinetics are discussed. Analytical expressions for the nucleation rate are obtained. The influence of the molecular nature of the ion on the nucleation rate is shown. Experimental evidence of the limiting regimes is presented.
A new technique has been developed to study the role of molecular properties in the ion nucleatio... more A new technique has been developed to study the role of molecular properties in the ion nucleation of supersaturated vapors. The method uses resonance enhanced multiphoton ionization (REMPI), to selectively ionize a chromophore present at low concentrations (mole fractions of < 10-3) in a steady-state supersaturated vapor produced in a diffusion cloud chamber (DCC). The combination of REMPI and the
Analytical Chemistry, Jun 1, 2001
Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and gen... more Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and generate tens of thousands of spectra from typical measurement campaigns. The ART-2a spectrum algorithm has been used to classify these spectra. In this work, we generate a range of particles that are models of those that are common in the atmosphere. A single-particle mass spectrometer is used to analyze these known particles, and the spectra are classified using ART-2a. The optimum vigilance parameter is ∼0.5 while the optimum learning rate is ∼0.05. The classifications elucidate limitations in generation of test particles, their analysis by single-particle techniques, and their classification by ART-2a.
Inhalation Toxicology, Sep 23, 2009
Cigarette mainstream smoke (MS) is a dynamic aerosol consisting of a gas-vapor phase and a partic... more Cigarette mainstream smoke (MS) is a dynamic aerosol consisting of a gas-vapor phase and a particulate phase. In recent years, novel in vitro whole smoke exposure systems have been developed to expose cells directly to whole MS. One such system is the Burghart Mimic Smoker-01 (MSB-01). Our previous data using the MSB-01 indicated that a 50 ± 10% loss of particulate matter occurred prior to MS delivery into the exposure chamber. Additionally, a change in aerosol particle diameter was also measured, suggesting that the chemical composition of MS might be changing within the system. In this study, we have expanded on our previous work and compared the particulate phase chemical composition of undiluted and diluted MS generated by the instrument and that of the MS delivered into the exposure chamber. The average percent delivery of cigarette smoke condensate (CSC) detected for all the measured chemical constituents was 35 ± 13% for undiluted MS and 23 ± 8% for 1:1 diluted MS. The data also indicate that under our experimental conditions, incomplete mixing of the freshly generated MS occurs during its dilution by the system. Taken together, the data presented here show that significant chemical changes occur between the generation of MS by the system and its delivery into the exposure chamber. This indicates that due to the dynamic nature of cigarette smoke, it is important to characterize the exposure conditions in order to gain the best insight and accurately correlate exposure with biological endpoints.
Environmental Science Technology, 2000
The Journal of Physical Chemistry, 1995
... to the Thomas F. and Kate Miller Jeffress Memorial Trust (5-302), and to the Exxon Education ... more ... to the Thomas F. and Kate Miller Jeffress Memorial Trust (5-302), and to the Exxon Education Foundation for the partial support of this research. References and Notes (1) Wilson, C. R. SOC. London. Philos. Trans. A 1989, 193, 289. (2) Loeb, LB; Kipp, AF; Einarson, AW J. Chem ...
Nucleation and Atmospheric Aerosols 1996, 1996
The Journal of Physical Chemistry A, 2000
... El-Shall*. Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 2328... more ... El-Shall*. Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284-2006. J. Phys. Chem. A , 2000, 104 (21), pp 49124919. DOI: 10.1021/jp991934g. Publication Date (Web): May 6, 2000. Copyright © 2000 American Chemical Society. Abstract. ...
The Journal of Chemical Physics, 1999
Recent measurements of critical supersaturations for the vapor phase homogeneous nucleation of se... more Recent measurements of critical supersaturations for the vapor phase homogeneous nucleation of several substances using a diffusion cloud chamber technique exhibit a dependence on the pressure of the carrier gas used in the experiments. A model of droplet growth and motion in a diffusion cloud chamber, combined with the density and temperature profiles of the chamber is presented to explain the pressure dependent results. The model demonstrates that at higher carrier gas pressures the growth of the droplets is retarded and the optical scattering signal from the particles is reduced. It is concluded that the observed effect may not result from a pressure dependence of the nucleation rate, but from a pressure dependence of the droplet growth and motion.
The Journal of Chemical Physics, 2005
A general solution for the steady-state ion-induced nucleation kinetics has been derived, conside... more A general solution for the steady-state ion-induced nucleation kinetics has been derived, considering the differences between ion-induced nucleation and homogeneous nucleation. This solution includes a new effect for nucleation kinetics, the interaction of charged clusters with vapor molecules. Analytical expressions for the ion-induced nucleation rate have been obtained for the limiting cases of high and low thermodynamic barriers. The physical explanation of the so-called sign effect is proposed based on multipole expansion of an electric field of the cluster ion. This theory gives good agreement with experiments and is used to elucidate experimentally observed phenomena.
Inhalation Toxicology, 2009
It is known that puffing conditions such as puff volume, duration, and frequency vary substantial... more It is known that puffing conditions such as puff volume, duration, and frequency vary substantially among individual smokers. This study investigates how these parameters affect the particle size distribution and concentration of fresh mainstream cigarette smoke (MCS) and how these changes affect the predicted deposition of MCS particles in a model human respiratory tract. Measurements of the particle size distribution made with an electrical low pressure impactor for a variety of puffing conditions are presented. The average flow rate of the puff is found to be the major factor effecting the measured particle size distribution of the MCS. The results of these measurements were then used as input to a deterministic dosimetry model (MPPD) to estimate the changes in the respiratory tract deposition fraction of smoke particles. The MPPD dosimetry model was modified by incorporating mechanisms involved in respiratory tract deposition of MCS: hygroscopic growth, coagulation, evaporation of semivolatiles, and mixing of the smoke with inhaled dilution air. The addition of these mechanisms to MPPD resulted in reasonable agreement between predicted airway deposition and human smoke retention measurements. The modified MPPD model predicts a modest 10% drop in the total deposition efficiency in a model human respiratory tract as the puff flow rate is increased from 1050 to 3100 ml/min, for a 2-s puff.
Inhalation Toxicology, 2009
In vitro systems are frequently used to study mechanisms of mainstream cigarette smoke (MS)induce... more In vitro systems are frequently used to study mechanisms of mainstream cigarette smoke (MS)induced lung injury. Traditional methods of exposure involve the capture of MS particulate phase with filter pads or bubbling MS through phosphate buffered saline (PBS) or cell culture medium. Although useful for in vitro experiments, these exposure methods may fail to capture potential interactions between the gas and particulate phases. To better understand the effect of MS on the human airway, in vitro whole smoke exposure systems that utilize freshly generated whole smoke are needed. Here we report the characterization of a new in vitro whole smoke exposure system (Burghart Mimic Smoker-01 (MSB-01)). This system uses a smoke distribution manifold to simultaneously deliver MS to each well of a 96-well plate. Intraday and interday variations for particulate matter deposition were less than 5% and 13% respectively. Cytotoxicity measurements using lung epithelial BEAS-2B cells indicate variations in calculated EC 50 (half maximal effective concentration) values of 13% intraday and 20% interday. Smoke particulate losses and changes in particle size distribution were also analyzed. The data indicate that 45-50% of the MS generated at the smoking ports is lost within the system prior to delivery into the exposure chamber; however, no changes in particle size distribution were detected throughout the system. Overall, the MSB-01 reproducibly delivered mainstream cigarette smoke in a dose dependent manner across the multiwell plate. The MSB-01 is a high throughput system capable of exposing cells to both the MS particulate and gas/vapor phases simultaneously.
Environmental Science & Technology, 2000
Chemical Physics Letters, 1997
ABSTRACT
Chemical Physics Letters, 1996
Resonance enhanced multiphoton ionization (REMPI) of aromatic molecules present in a small concen... more Resonance enhanced multiphoton ionization (REMPI) of aromatic molecules present in a small concentration within a supersaturated host vapor is demonstrated. The method is applied to the study of ion nucleation in supersaturated vapors of methanol, acetoniWile and nonane induced by the molecular ions of benzene, toluene, and p-xylene. With this method it is now possible to selectively and unambiguously generate specific ions of interest and study their nucleating behavior. Furthermore, the selectivity of REMPI combined with the amplification and detection capabilities of nucleation and growth offer valuable analytical features for the identification of trace components in supersaturated vapors.
Analytical Chemistry, 2001
Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and gen... more Single-particle mass spectrometers are now commonly used to analyze atmospheric particles and generate tens of thousands of spectra from typical measurement campaigns. The ART-2a spectrum algorithm has been used to classify these spectra. In this work, we generate a range of particles that are models of those that are common in the atmosphere. A single-particle mass spectrometer is used to analyze these known particles, and the spectra are classified using ART-2a. The optimum vigilance parameter is ∼0.5 while the optimum learning rate is ∼0.05. The classifications elucidate limitations in generation of test particles, their analysis by single-particle techniques, and their classification by ART-2a.