Roberts, KA
1990
Fast, Repetitive GC/MS Analysis of Thermally Desorbed Polycyclic Aromatic Hydrocarbons (PAHs) from Contaminated Soils
McClennen, W.H.; Arnold, N.S.; Roberts, K.A.; Meuzelaar, H.L.C.; Lighty, J.S. and Lindgren, E.R.
Combustion Science and Technology, 1990 (In press). Sponsored by Remediation Technology, Gas Research Institute, ACERC, Finnigan Corp. and IT Corporation.
A system for on-line analysis of organic vapors by short column gas chromatography/mass spectrometry (GC/MS) has been used to monitor products from a thermal soil desorption reactor. The system consists of a unique air-sampling inlet with a 1-meter long capillary column coupled directly to a modified Ion Trap Mass Spectrometer (Finnigan MAT) with demonstrated detection limits for alkylbenzenes in the low ppb range. In this work the mobile instrument is used for repetitive GC/MS and GC/MS (tandem MS) analysis at 30 to 60 sec intervals of PAH products from coal tar contaminated soils in a bed characterization reactor.
Results for napthalene through dibenzanthracenes are compared to conventional, more detailed GC/MS analyses of extracts from the soil before and after thermal treatment.
A combustion map of burnout values was made using the laboratory nozzle at an A/S of 0.7, swirl number of 1.5 and SR of 1.1.
1989
Laser Pyrolysis Mass Spectrometry of Single Levitated Coal Particles
Maswadeh, W.; Roberts, K.A.; McClennen, W.H.; Meuzelaar, H.L.C. and Arnold, N.S.
37th ASMS Conference on Mass Spectrometry and Allied Topics, Miami Beach, Florida, 304-305, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates), US Department of Energy, and the State of Utah.
A laser pyrolysis mass spectrometry experiment was designed to study the devolatilization behavior of individual coal particles at high heating rates (104-106 K/s), characteristic of pulverized coal combustion reactors. The experimental set-up consists of an electrostatic particle levitation cell, also known as an "electrodynamic balance", a 50 W cw CO2 laser and a Finnigan-MAT ITMS system. The particle levitation cell was constructed by modifying a regular ion trap electrode assembly in such a way as to provide line-of-sight access to the center of the cell for the CO2 laser beam as well as for visual observation by means of a stereo microscope. Typical cell operating parameters for levitating a 120 mm dia. Spherocarb particle are: ring electrode 3000 V (60 Hz ac), upper end-cap +100 V dc, lower end-cap -100 V dc. The CO2 laser (Apollo 3050 OEM) is capable of electronic pulsed beam operation. The 8 mm dia. beam is split equally into 2 opposing beams focused at the center of the levitation cell (beam waist ca. 400 um, power density ca. 4-10 MW/m2), as a co-linear parfocal HeNe laser beam permits positioning the levitated particle in the optical and electrical center of the cell. Two IR detectors measure the integrated pulse and time-resolved pulse energy.
A heated transfer line column (2m x .18 mm DB5) equipped with a special air sampling inlet enables intermittent sampling of volatiles from the center of the levitation cell into the ITMS vacuum system. Feasibility studies were performed on 120-150 mm Spherocarb particles impregnated with an alkylnaphthalenes mixture and heated with a single 10 ms CO2 laser pulse. Ample signal intensities were obtained with the first laser pulse to permit the recording of "transfer line" GC/MS profiles. By contrast, the second laser pulse produced <10% of the volatiles observed from the first pulse, thereby demonstrating nearly complete devolatilization of the impregnated particle by a single laser pulse.
Finally, a series of experiments was performed with actual coal particles in the 100-130 mm size range, prepared by careful sieving of two coals from the Argonne National Laboratory Premium Coal Sample bank, namely a Pittsburgh #8 seam (Illinois) coal and a Blind Canyon seam (Utah) coal of comparable rank. From previous studies of Pitt. #8 coal using time-resolved Curie-point pyrolysis, pyrolysis temperatures necessary to produce these phenolic building blocks at heating rates of 105 K/sec are estimated to be ca. 900 K. Of course, kinetic parameters obtained at the much lower heating rates of the Curie-point pyrolysis MS experiment (approx. 102 K/s) may only be extrapolated to the laser pyrolysis experiment if the underlying reaction mechanisms are comparable. Evidence supporting this assumption is presented showing similar C1 and C2-alkyl phenol profiles for the Pitt. #8 coal obtained by Curie-point pyrolysis GC/MS using a 15 m fused silica capillary with temperature programming.
Direct On-Site Vapor Monitoring by Transfer Line GC/MS
Arnold, N.S.; Roberts, K.A.; McClennen, W.H. and Meuzelaar, H.L.C.
Proc. 37th ASMS Conference on Mass Spectrometry and Allied Topics, Miami Beach, Florida, 1424-1426, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, US Department of Energy, the Department of Defense Chemical Research Development and Engineering Center and Finnigan-MAT Corp.
A direct atmospheric vapor sampling inlet has been used for on-line monitoring of vapors in laboratory scale reactors. The inlet consists of three concentric tubes with appropriate flow control plumbing and electronics. This inlet provides for direct introduction of a pulse of air (.5 to 2 s) into a short (1 m) coated fused silica capillary column enclosed in the heated transfer line housing of a Finnigan-MAT ITD. Effluent from the column emerges directly into the ion trap. Data presented here were obtained by sampling from a bed-characterization reactor (for waste disposal studies) using the MINITMASS, a modified mobile Ion Trap Mass Spectrometer. (Alternate sampling environments have included a coal combustor, an open air chemical release, a micro-scale laser pyrolysis chamber, and in-building ambient atmospheres.) Vapor samples were obtained repetitively at 60 s intervals, allowing for an isothermal GC separation of various components. A ~1.5 s vapor sample allowed up to 100 ul (@STP) of reactor atmosphere to enter the transfer line for chromatographic separation. A .18 mm ID transfer line with a .4 um DB-5 coating (J+W Scientific) was operated isothermally at either 25º, 80º or 125ºC. Carrier gas (helium) velocity was -2.7 m/s (at column temp=25ºC and 4400 ft elevation). All analyses were performed using electron impact ionization. Detection limits have been established near the 1 ppb level for various substituted aromatic compounds using this (MINITMASS) system and taking advantage of the Axial Modulation* and Selective Mass Storage* features to improve sensitivity. Estimations of concentration in this presentation are provided from the calibration data obtained on toluene, ethylbenzene, o-, m-, and p-xylene and general sensitivity characteristics of ion trap mass spectrometers for the compounds of interest. In the present analyses, halogen-, nitrogen- and oxygen-substituted aromatics have been detected at <100 ppb. Various column temperatures allowed for analysis of compounds with atmospheric boiling points from 80ºC (benzene) to 350ºC (anthracene) present in reactor vapors. To date, test analyses of high boiling compounds than these have required the reactor be run under nitrogen to prevent rapid column degradation, though compounds as involatile as dibenzanthracenes (bp 550ºC) have been detected under test conditions.
Monitoring the Evolution of Organic Compounds from the Thermal Treatment of Contaminated Soil Samples Using Short Column GC/MS
McClennen, W.H.; Arnold, N.S.; Lighty, J.S.; Eddings, E.G.; Lindgren, E.R.; Roberts, K.A. and Meuzelaar, H.L.C.
Preprints of Papers Presented at the 198th ACS National Meeting, 34 (3), Miami Beach, Florida, 1989. Funded by the Gas Research Institute, Dave Linz, Project Manager, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
Incineration is an effective technology for the remediation of organic chemical contaminated wastes. For solid wastes, such as contaminated soils, processes involving separate stages of a primary desorber and secondary afterburner are particularly useful. The desorption stage is currently being modeled using a particle-characterization reactor (PCR, 0-500 g capacity), a bed-characterization reactor (BCR, 0.5-5 kg), and a rotary kiln simulator (2-15 kg) to study fundamental processes such as mass transfer, heat transfer, and volatilization of contaminants. This paper describes the analytical methods and preliminary results from monitoring the evolution of organic compounds in these and smaller reactors.
The samples are soil contaminated with a broad range of polynuclear aromatic (PNA) hydrocarbons such as those derived from coal tars. The analytical methods primarily involve mass spectrometry (MS) with a variety of sample introduction techniques. The on-going analyses include solvent and thermal extractions of soil before and after various thermal treatments as well as on-line monitoring of vapors during desorption.
Fast, Repetitive GC/MS Analysis of Thermally Desorbed Polycyclic Aromatic Hydrocarbons (PAHs) from Contaminated Soils
McClennen, W.H.; Arnold, N.S.; Roberts, K.A.; Meuzelaar, H.L.C.; Lighty, J.S. and Lindgren, E.R.
1st International Congress on Toxic Combustion, 1989. Funded by Remediation Technologies, the Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A system for on-line analysis of organic vapors by short column gas chromatography/mass spectrometry (CG/MS) has been used to monitor products from a thermal soil desorption reactor. The system consists of a unique air-sampling inlet with a 1 meter long capillary column coupled directly to a modified Ion Trap Mass Spectrometer (Finnigan MAT) with demonstrated detection limits for alkylbenzenes in the low ppb range. In this work the mobile instrument is used for repetitive GC/MS and GC/MSn (tandem MS) analysis at 30 to 60 sec intervals of PAH products from coal tar contaminated soils in a bed characterization reactor.
Results for naphthalene through dibenzanthracenes are compared to conventional, more detailed GC/MS analyses of extracts from the soil before and after thermal treatment.
1987
Novel Mass Spectrometric Techniques for Coal Devolatilization Studies
Meuzelaar, H.L.C.; Roberts, K.A. and Yun, Y.
Western States Combustion Institute Proceedings, 1987. Funded by ACERC (National Science Foundation and Associates and Affiliates).
Among modern spectroscopic techniques applied to the study of coal devolatilization processes Fourier transform infrared spectroscopy (FTIR) has established a prominent position whereas comparatively little use has been made of mass spectrometry (MS), in spite of its widely recognized speed, sensitivity and high information yields.
Roberts, KA
1990
Fast, Repetitive GC/MS Analysis of Thermally Desorbed Polycyclic Aromatic Hydrocarbons (PAHs) from Contaminated Soils
McClennen, W.H.; Arnold, N.S.; Roberts, K.A.; Meuzelaar, H.L.C.; Lighty, J.S. and Lindgren, E.R.
Combustion Science and Technology, 1990 (In press). Sponsored by Remediation Technology, Gas Research Institute, ACERC, Finnigan Corp. and IT Corporation.
A system for on-line analysis of organic vapors by short column gas chromatography/mass spectrometry (GC/MS) has been used to monitor products from a thermal soil desorption reactor. The system consists of a unique air-sampling inlet with a 1-meter long capillary column coupled directly to a modified Ion Trap Mass Spectrometer (Finnigan MAT) with demonstrated detection limits for alkylbenzenes in the low ppb range. In this work the mobile instrument is used for repetitive GC/MS and GC/MS (tandem MS) analysis at 30 to 60 sec intervals of PAH products from coal tar contaminated soils in a bed characterization reactor.
Results for napthalene through dibenzanthracenes are compared to conventional, more detailed GC/MS analyses of extracts from the soil before and after thermal treatment.
A combustion map of burnout values was made using the laboratory nozzle at an A/S of 0.7, swirl number of 1.5 and SR of 1.1.
1989
Laser Pyrolysis Mass Spectrometry of Single Levitated Coal Particles
Maswadeh, W.; Roberts, K.A.; McClennen, W.H.; Meuzelaar, H.L.C. and Arnold, N.S.
37th ASMS Conference on Mass Spectrometry and Allied Topics, Miami Beach, Florida, 304-305, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates), US Department of Energy, and the State of Utah.
A laser pyrolysis mass spectrometry experiment was designed to study the devolatilization behavior of individual coal particles at high heating rates (104-106 K/s), characteristic of pulverized coal combustion reactors. The experimental set-up consists of an electrostatic particle levitation cell, also known as an "electrodynamic balance", a 50 W cw CO2 laser and a Finnigan-MAT ITMS system. The particle levitation cell was constructed by modifying a regular ion trap electrode assembly in such a way as to provide line-of-sight access to the center of the cell for the CO2 laser beam as well as for visual observation by means of a stereo microscope. Typical cell operating parameters for levitating a 120 mm dia. Spherocarb particle are: ring electrode 3000 V (60 Hz ac), upper end-cap +100 V dc, lower end-cap -100 V dc. The CO2 laser (Apollo 3050 OEM) is capable of electronic pulsed beam operation. The 8 mm dia. beam is split equally into 2 opposing beams focused at the center of the levitation cell (beam waist ca. 400 um, power density ca. 4-10 MW/m2), as a co-linear parfocal HeNe laser beam permits positioning the levitated particle in the optical and electrical center of the cell. Two IR detectors measure the integrated pulse and time-resolved pulse energy.
A heated transfer line column (2m x .18 mm DB5) equipped with a special air sampling inlet enables intermittent sampling of volatiles from the center of the levitation cell into the ITMS vacuum system. Feasibility studies were performed on 120-150 mm Spherocarb particles impregnated with an alkylnaphthalenes mixture and heated with a single 10 ms CO2 laser pulse. Ample signal intensities were obtained with the first laser pulse to permit the recording of "transfer line" GC/MS profiles. By contrast, the second laser pulse produced <10% of the volatiles observed from the first pulse, thereby demonstrating nearly complete devolatilization of the impregnated particle by a single laser pulse.
Finally, a series of experiments was performed with actual coal particles in the 100-130 mm size range, prepared by careful sieving of two coals from the Argonne National Laboratory Premium Coal Sample bank, namely a Pittsburgh #8 seam (Illinois) coal and a Blind Canyon seam (Utah) coal of comparable rank. From previous studies of Pitt. #8 coal using time-resolved Curie-point pyrolysis, pyrolysis temperatures necessary to produce these phenolic building blocks at heating rates of 105 K/sec are estimated to be ca. 900 K. Of course, kinetic parameters obtained at the much lower heating rates of the Curie-point pyrolysis MS experiment (approx. 102 K/s) may only be extrapolated to the laser pyrolysis experiment if the underlying reaction mechanisms are comparable. Evidence supporting this assumption is presented showing similar C1 and C2-alkyl phenol profiles for the Pitt. #8 coal obtained by Curie-point pyrolysis GC/MS using a 15 m fused silica capillary with temperature programming.
Direct On-Site Vapor Monitoring by Transfer Line GC/MS
Arnold, N.S.; Roberts, K.A.; McClennen, W.H. and Meuzelaar, H.L.C.
Proc. 37th ASMS Conference on Mass Spectrometry and Allied Topics, Miami Beach, Florida, 1424-1426, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, US Department of Energy, the Department of Defense Chemical Research Development and Engineering Center and Finnigan-MAT Corp.
A direct atmospheric vapor sampling inlet has been used for on-line monitoring of vapors in laboratory scale reactors. The inlet consists of three concentric tubes with appropriate flow control plumbing and electronics. This inlet provides for direct introduction of a pulse of air (.5 to 2 s) into a short (1 m) coated fused silica capillary column enclosed in the heated transfer line housing of a Finnigan-MAT ITD. Effluent from the column emerges directly into the ion trap. Data presented here were obtained by sampling from a bed-characterization reactor (for waste disposal studies) using the MINITMASS, a modified mobile Ion Trap Mass Spectrometer. (Alternate sampling environments have included a coal combustor, an open air chemical release, a micro-scale laser pyrolysis chamber, and in-building ambient atmospheres.) Vapor samples were obtained repetitively at 60 s intervals, allowing for an isothermal GC separation of various components. A ~1.5 s vapor sample allowed up to 100 ul (@STP) of reactor atmosphere to enter the transfer line for chromatographic separation. A .18 mm ID transfer line with a .4 um DB-5 coating (J+W Scientific) was operated isothermally at either 25º, 80º or 125ºC. Carrier gas (helium) velocity was -2.7 m/s (at column temp=25ºC and 4400 ft elevation). All analyses were performed using electron impact ionization. Detection limits have been established near the 1 ppb level for various substituted aromatic compounds using this (MINITMASS) system and taking advantage of the Axial Modulation* and Selective Mass Storage* features to improve sensitivity. Estimations of concentration in this presentation are provided from the calibration data obtained on toluene, ethylbenzene, o-, m-, and p-xylene and general sensitivity characteristics of ion trap mass spectrometers for the compounds of interest. In the present analyses, halogen-, nitrogen- and oxygen-substituted aromatics have been detected at <100 ppb. Various column temperatures allowed for analysis of compounds with atmospheric boiling points from 80ºC (benzene) to 350ºC (anthracene) present in reactor vapors. To date, test analyses of high boiling compounds than these have required the reactor be run under nitrogen to prevent rapid column degradation, though compounds as involatile as dibenzanthracenes (bp 550ºC) have been detected under test conditions.
Monitoring the Evolution of Organic Compounds from the Thermal Treatment of Contaminated Soil Samples Using Short Column GC/MS
McClennen, W.H.; Arnold, N.S.; Lighty, J.S.; Eddings, E.G.; Lindgren, E.R.; Roberts, K.A. and Meuzelaar, H.L.C.
Preprints of Papers Presented at the 198th ACS National Meeting, 34 (3), Miami Beach, Florida, 1989. Funded by the Gas Research Institute, Dave Linz, Project Manager, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
Incineration is an effective technology for the remediation of organic chemical contaminated wastes. For solid wastes, such as contaminated soils, processes involving separate stages of a primary desorber and secondary afterburner are particularly useful. The desorption stage is currently being modeled using a particle-characterization reactor (PCR, 0-500 g capacity), a bed-characterization reactor (BCR, 0.5-5 kg), and a rotary kiln simulator (2-15 kg) to study fundamental processes such as mass transfer, heat transfer, and volatilization of contaminants. This paper describes the analytical methods and preliminary results from monitoring the evolution of organic compounds in these and smaller reactors.
The samples are soil contaminated with a broad range of polynuclear aromatic (PNA) hydrocarbons such as those derived from coal tars. The analytical methods primarily involve mass spectrometry (MS) with a variety of sample introduction techniques. The on-going analyses include solvent and thermal extractions of soil before and after various thermal treatments as well as on-line monitoring of vapors during desorption.
Fast, Repetitive GC/MS Analysis of Thermally Desorbed Polycyclic Aromatic Hydrocarbons (PAHs) from Contaminated Soils
McClennen, W.H.; Arnold, N.S.; Roberts, K.A.; Meuzelaar, H.L.C.; Lighty, J.S. and Lindgren, E.R.
1st International Congress on Toxic Combustion, 1989. Funded by Remediation Technologies, the Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A system for on-line analysis of organic vapors by short column gas chromatography/mass spectrometry (CG/MS) has been used to monitor products from a thermal soil desorption reactor. The system consists of a unique air-sampling inlet with a 1 meter long capillary column coupled directly to a modified Ion Trap Mass Spectrometer (Finnigan MAT) with demonstrated detection limits for alkylbenzenes in the low ppb range. In this work the mobile instrument is used for repetitive GC/MS and GC/MSn (tandem MS) analysis at 30 to 60 sec intervals of PAH products from coal tar contaminated soils in a bed characterization reactor.
Results for naphthalene through dibenzanthracenes are compared to conventional, more detailed GC/MS analyses of extracts from the soil before and after thermal treatment.
1987
Novel Mass Spectrometric Techniques for Coal Devolatilization Studies
Meuzelaar, H.L.C.; Roberts, K.A. and Yun, Y.
Western States Combustion Institute Proceedings, 1987. Funded by ACERC (National Science Foundation and Associates and Affiliates).
Among modern spectroscopic techniques applied to the study of coal devolatilization processes Fourier transform infrared spectroscopy (FTIR) has established a prominent position whereas comparatively little use has been made of mass spectrometry (MS), in spite of its widely recognized speed, sensitivity and high information yields.