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Evans-Nguyen K, Stelmack AR, Clowser PC, Holtz JM, Mulligan CC. FIELDABLE MASS SPECTROMETRY FOR FORENSIC SCIENCE, HOMELAND SECURITY, AND DEFENSE APPLICATIONS. MASS SPECTROMETRY REVIEWS 2021; 40:628-646. [PMID: 32722885 DOI: 10.1002/mas.21646] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 02/24/2020] [Indexed: 05/26/2023]
Abstract
Mass spectrometry is commonly used in forensic chemistry laboratories for sensitive, definitive analysis. There have been significant efforts to bring mass spectrometry analysis on-site through the development of ruggedized, fieldable instruments. Testing samples in the field is of particular interest in forensic science, homeland security, and defense applications. In forensic chemistry, testing seized drugs in the field can significantly improve efficiencies in processing of related criminal cases. The screening of passengers and luggage at transportation hubs is a critical need for homeland security for which mass spectrometry is well suited to provide definitive answers with low false positive rates. Mass spectrometry can yield reliable data for military personnel testing sites for potential chemical weapons release. To meet the needs of the forensic and security communities fieldable mass spectrometers based on membrane inlet systems and hybrid gas chromatography systems have been developed and commercialized. More recently developed ambient ionization mass spectrometry methods can eliminate the time, equipment, and expertise associated with sample preparation, and so are especially appealing for on-site analysis. We describe the development of fieldable mass spectrometry systems, with emphasis on commercially available systems that have been deployed for on-site analysis of seized drugs, chemical warfare agents, explosives, and other analytes of interest to the forensic and security communities. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.
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Affiliation(s)
- Kenyon Evans-Nguyen
- Department of Chemistry, Biochemistry and Physics, University of Tampa, Tampa, FL
| | | | | | - Jessica M Holtz
- Department of Chemistry, Illinois State University, Normal, IL
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Giannoukos S, Brkić B, Taylor S, France N. Membrane inlet mass spectrometry for homeland security and forensic applications. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:231-239. [PMID: 25398262 DOI: 10.1007/s13361-014-1032-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 10/20/2014] [Accepted: 10/21/2014] [Indexed: 06/04/2023]
Abstract
A man-portable membrane inlet mass spectrometer has been built and tested to detect and monitor characteristic odors emitted from the human body and also from threat substances. In each case, a heated membrane sampling probe was used. During human scent monitoring experiments, data were obtained for inorganic gases and volatile organic compounds emitted from human breath and sweat in a confined space. Volatile emissions were detected from the human body at low ppb concentrations. Experiments with compounds associated with narcotics, explosives, and chemical warfare agents were conducted for a range of membrane types. Test compounds included methyl benzoate (odor signature of cocaine), piperidine (precursor in clandestine phencyclidine manufacturing processes), 2-nitrotoluene (breakdown product of TNT), cyclohexanone (volatile signature of plastic explosives), dimethyl methylphosphonate (used in sarin and soman nerve agent production), and 2-chloroethyl ethyl sulfide (simulant compound for sulfur mustard gas). Gas phase calibration experiments were performed allowing sub-ppb LOD to be established. The results showed excellent linearity versus concentration and rapid membrane response times.
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Affiliation(s)
- Stamatios Giannoukos
- Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool, L69 3GJ, UK
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Ewing RG, Heredia-Langner A, Warner MG. Optimizing detection of RDX vapors using designed experiments for remote sensing. Analyst 2014; 139:2440-8. [DOI: 10.1039/c4an00125g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Giannoukos S, Brkić B, Taylor S, France N. Monitoring of human chemical signatures using membrane inlet mass spectrometry. Anal Chem 2013; 86:1106-14. [PMID: 24377277 DOI: 10.1021/ac403621c] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work is an attempt to assist border security crackdown on illegal human immigration, by providing essential results on human chemical signatures. Data was obtained using a portable quadrupole mass spectrometer coupled with a membrane probe for volunteers of both genders and under different conditions in a container simulator. During experiments, participants were asked to follow various protocols while volatile organic compounds emitted from their breath, sweat, skin, and other biological excretes were continuously being monitored. Experimental setups using different membrane materials (both hydrophilic and hydrophobic) including heating of the sampling probe and sampling flow rates were examined. From our measurements, significant information was obtained for NH3, CO2, water, and volatile organic compounds levels, illustrating a human chemical profile and indicating human presence in a confined space.
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Affiliation(s)
- Stamatios Giannoukos
- Department of Electrical Engineering and Electronics, University of Liverpool , Brownlow Hill, Liverpool, L69 3GJ, United Kingdom
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Ewing KJ, Gibson D, Sanghera J, Miklos F. Sampler for Collection and Analysis of Low Vapor Pressure Chemical (LVPC) Particulates/Aerosols. Anal Chem 2013; 85:9508-13. [DOI: 10.1021/ac401100r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- K. J. Ewing
- Naval Research Laboratory, Code
5620, Washington, DC
| | - D. Gibson
- Naval Research Laboratory, Code
5620, Washington, DC
| | - J. Sanghera
- Naval Research Laboratory, Code
5620, Washington, DC
| | - F. Miklos
- Sotera Defense Solutions, 2121 Cooperative Way, Herndon, VA
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Duncan KD, Willis MD, Krogh ET, Gill CG. A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for direct and on-line measurements of pharmaceuticals and contaminants in small, complex samples. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:1213-1221. [PMID: 23650034 DOI: 10.1002/rcm.6560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 02/22/2013] [Accepted: 02/23/2013] [Indexed: 06/02/2023]
Abstract
RATIONALE High-throughput, automated analytical measurements are desirable in many analytical scenarios, as are rapid sample pre-screening techniques to identify 'positive' samples for subsequent measurements using more time-consuming conventional methodologies (e.g., liquid chromatography/mass spectrometry (LC/MS)). A miniature condensed-phase membrane introduction mass spectrometry (CP-MIMS) probe for the direct and continuous, on-line measurement of pharmaceuticals and environmental contaminants in small, complex samples is presented. METHODS A miniature polydimethylsiloxane hollow fibre membrane (PDMS-HFM) probe is coupled with an electrospray ionization (ESI) triple quadrupole mass spectrometer. Analytes are transported from the probe to the ESI source by a methanol acceptor phase. The probe can be autosampler mounted and directly inserted in small samples (≥400 μL) allowing continuous and simultaneous pptr-ppb level detection of target analytes (chlorophenols, triclosan, gemfibrozil, nonylphenol) in complex samples (artificial urine, beer, natural water, waste water, plant tissue). RESULTS The probe has been characterized and optimized for acceptor phase flow rate, sample mixing and probe washing. Signal response times, detection limits and calibration data are given for selected ion monitoring (SIM) and tandem mass spectrometry (MS/MS) measurements of target analytes at trace levels. Comparisons with flow cell type CP-MIMS systems are given. Analyte depletion effects are evaluated for small samples (≥400 μL). On-line measurements in small volumes of complex samples, temporally resolved reaction monitoring and in situ/in vivo demonstrations are presented. CONCLUSIONS The miniature CP-MIMS probe developed was successfully used for the direct, on-line detection of target analytes in small volumes (40 mL to 400 μL) of complex samples at pptr to low ppb levels. The probe can be readily automated as well as deployed for in situ/in vivo monitoring, including reaction monitoring, small sample measurements and direct insertion in living plant tissue.
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Affiliation(s)
- Kyle D Duncan
- Department of Chemistry, University of Victoria, Victoria, British Columbia, Canada
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Collection method for chemical particulates on surfaces with detection using thermal desorption-ion trap mass spectrometry. Anal Chim Acta 2013; 776:64-8. [DOI: 10.1016/j.aca.2013.03.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/12/2013] [Accepted: 03/17/2013] [Indexed: 11/17/2022]
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Sae-Khow O, Mitra S. Pervaporation in chemical analysis. J Chromatogr A 2010; 1217:2736-46. [DOI: 10.1016/j.chroma.2009.12.043] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2009] [Revised: 12/11/2009] [Accepted: 12/14/2009] [Indexed: 10/20/2022]
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Identification of volatile chemical signatures from plastic explosives by SPME-GC/MS and detection by ion mobility spectrometry. Anal Bioanal Chem 2010; 396:2997-3007. [DOI: 10.1007/s00216-010-3501-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Revised: 01/19/2010] [Accepted: 01/20/2010] [Indexed: 11/26/2022]
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Aguilera-Herrador E, Lucena R, Cárdenas S, Valcárcel M. Ionic liquid-based single drop microextraction and room-temperature gas chromatography for on-site ion mobility spectrometric analysis. J Chromatogr A 2009; 1216:5580-7. [DOI: 10.1016/j.chroma.2009.05.071] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 05/25/2009] [Accepted: 05/25/2009] [Indexed: 10/20/2022]
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Gernátová M, Janderka P, Marcinková A, Ostríz P. Use of Nafion as a membrane separator in membrane introduction of mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2009; 15:571-577. [PMID: 19679937 DOI: 10.1255/ejms.1001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nafion is a commercially available perfluorosulphonate cation exchange membrane commonly used as a perm-selective separator in chlor-alkali electrolysers and as the electrolyte in solid polymer fuel cells. In our experiments, a Nafion sheet membrane serves as the interface between the aqueous sample and the vacuum in membrane introduction to the mass spectrometer (MIMS). The penetration by volatile polar compounds (VOC-methanol, ethanol, 1-propanol), volatile non-polar compounds (VOC-benzene, toluene and p- xylene), semi-volatile low polar compounds (SVOC-fluorobenzene, chlorobenzene and bromobenzene) and non-volatile polar compounds (o-chlorophenol, m-chlorophenol and p-chlorophenol) in aqueous solution through the Nafion membrane to the mass spectrometer was studied. In all cases, a simple fragmentation pattern of the intact molecule was observed, typically with m/z = nominal mass + 1 as the most intensive ion current, which suggests that the ionisation process takes part in which water acts as the chemical ionisation reagent. No additional gases were needed for chemical ionisation. We also measured detection limits and linear dynamic ranges of all observed compounds with Nafion membrane MIMS. The observed detection limits were in the order of ppb for the alcohol and aromatic groups and for the halogenbenzene and monochlorophenol groups they were in the order of ppm. Linear dynamic ranges for all tested compounds were one order of magnitude.
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Affiliation(s)
- Matilda Gernátová
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlárská 2, 611 37 Brno, Czech Republic.
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Yang M, Kim TY, Hwang HC, Yi SK, Kim DH. Development of a palm portable mass spectrometer. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2008; 19:1442-1448. [PMID: 18565759 DOI: 10.1016/j.jasms.2008.05.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 05/08/2008] [Accepted: 05/13/2008] [Indexed: 05/26/2023]
Abstract
A palm portable mass spectrometer (PPMS) has been developed with a weight of 1.48 kg (3 lb) and a size of 1.54 L (8.2 x 7.7 x 24.5 cm(3)) that can be operated with an average battery power of 5 W. A miniaturized ion trap has been used as a mass analyzer that consists of four parallel disks with coaxial holes. A rf voltage of 1500 V(p-p) at 3.9 MHz has been used for scanning ion mass of up to m/z 300. An ion-getter pump serves for high vacuum of the PPMS. Sample gas was introduced in pulse mode. An embedded microcomputer has been developed for system control. Detection of organic gases diluted in the air has been demonstrated up to 6 ppm for toluene and 22 ppm for dimethyl methylphosphonate (DMMP). Performance results suggest usefulness of the PPMS as a personal mobile device for detection/identification of chemical warfare agents in the field.
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Affiliation(s)
- Mo Yang
- Analytical Instrumentation Research Institute, Sam Yang Chemical Company, Seoul, Korea.
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da Silva RC, Zuin VG, Yariwake JH, Eberlin MN, Augusto F. Fiber introduction mass spectrometry: determination of pesticides in herbal infusions using a novel sol-gel PDMS/PVA fiber for solid-phase microextraction. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:1358-62. [PMID: 17902108 DOI: 10.1002/jms.1323] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
An application of the direct coupling of solid-phase microextraction (SPME) with mass spectrometry (MS), a technique known as fiber introduction mass spectrometry (FIMS), is described to determine organochlorine (OCP) and organophosphorus (OPP) pesticides in herbal infusions of Passiflora L. A new fiber coated with a composite of poly(dimethylsiloxane) and poly(vinyl alcohol) (PDMS/PVA) was used. Sensitive, selective, simple and simultaneous quantification of several OCP and OPP was achieved by monitoring diagnostic fragment ions of m/z 266 (chlorothalonil), m/z 195 (alpha-endosulfan), m/z 278 (fenthion), m/z 263 (methyl parathion) and m/z 173 (malathion). Simple headspace SPME extraction (25 min) and fast FIMS detection (less than 40 s) of OCP and OPP from a highly complex herbal matrix provided good linearity with correlation coefficients of 0.991-0.999 for concentrations ranging from 10 to 140 ng ml(-1) of each compound. Good accuracy (80 to 110%), precision (0.6-14.9%) and low limits of detection (0.3-3.9 ng ml(-1)) were also obtained. Even after 400 desorption cycles inside the ionization source of the mass spectrometer, no visible degradation of the novel PDMS/PVA fiber was detected, confirming its suitability for FIMS. Fast (ca 20 s) pesticide desorption occurs for the PDMS/PVA fiber owing to the small thickness of the film and its reduced water sorption.
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Affiliation(s)
- Rogério Cesar da Silva
- ThoMSon Mass Spectrometry laboratory, Institute of Chemistry, State University of Campinas, 13084-971 Campinas, SP, Brazil
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da Silva RC, Zuin VG, Yariwake JH, Eberlin MN, Augusto F. Fiber introduction mass spectrometry: determination of pesticides in herbal infusions using a novel sol-gel PDMS/PVA fiber for solid-phase microextraction. JOURNAL OF MASS SPECTROMETRY : JMS 2007; 42:825-9. [PMID: 17538979 DOI: 10.1002/jms.1223] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
An application of the direct coupling of solid-phase microextraction (SPME) with mass spectrometry (MS), a technique known as fiber introduction mass spectrometry (FIMS), is described to determine organochlorine (OCP) and organophosphorus (OPP) pesticides in herbal infusions of Passiflora L. A new fiber coated with a composite of poly(dimethylsiloxane) and poly(vinyl alcohol) (PDMS/PVA) was used. Sensitive, selective, simple and simultaneous quantification of several OCP and OPP was achieved by monitoring diagnostic fragment ions of m/z 266 (chlorothalonil), m/z 195 (alpha-endosulfan), m/z 278 (fenthion), m/z 263 (methyl parathion) and m/z 173 (malathion). Simple headspace SPME extraction (25 min) and fast FIMS detection (less than 40 s) of OCP and OPP from a highly complex herbal matrix provided good linearity with correlation coefficients of 0.991-0.999 for concentrations ranging from 10 to 140 ng ml(-1) of each compound. Good accuracy (80 to 110%), precision (0.6-14.9%) and low limits of detection (0.3-3.9 ng ml(-1)) were also obtained. Even after 400 desorption cycles inside the ionization source of the mass spectrometer, no visible degradation of the novel PDMS/PVA fiber was detected, confirming its suitability for FIMS. Fast (ca 20 s) pesticide desorption occurs for the PDMS/PVA fiber owing to the small thickness of the film and its reduced water sorption.
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Affiliation(s)
- Rogério Cesar da Silva
- ThoMSon Mass Spectrometry laboratory, Institute of Chemistry, State University of Campinas, 13084-971, Campinas, SP, Brazil
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Hylton K, Mitra S. Automated, on-line membrane extraction. J Chromatogr A 2007; 1152:199-214. [PMID: 17275830 DOI: 10.1016/j.chroma.2006.12.047] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Revised: 11/30/2006] [Accepted: 12/01/2006] [Indexed: 11/29/2022]
Abstract
Over the last few years, membranes have been used to develop new approaches in analytical extraction, concentration and cleanup. An important advantage of membrane processes is that the sample and the extraction phase can be continuously brought into contact without physical mixing, and may be directly interfaced to an analytical instrument. This provides the basis for automated, real-time monitoring. Membrane extraction has been applied to a wide range of organic and inorganic analytes, and has been directly interfaced with chromatography, spectroscopy and mass spectrometry. Implementations of membrane extraction are diverse, encompassing different types of membranes, module designs and configurations. This review highlights some of these, and particularly the unique capabilities in automated, and on-line measurements.
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Affiliation(s)
- Kamilah Hylton
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, University Heights, Newark, NJ 07104, USA
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Frandsen H, Janfelt C, Lauritsen FR. Fast and direct screening of polyaromatic hydrocarbon (PAH)-contaminated sand using a miniaturized membrane inlet mass spectrometer (mini-MIMS). RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:1574-8. [PMID: 17428015 DOI: 10.1002/rcm.3000] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
A miniaturized membrane inlet mass spectrometer (mini-MIMS; total weight 10 kg everything included) was equipped with a small sample cell using a flat sheet silicone membrane mounted close to the ionizing region of a multipole mass spectrometer. Spiked sand samples were placed in small stainless steel vials and dropped into the heated sample cell (>150 degrees C). A hole in the vial in front of the membrane and above the sand made it possible for the polyaromatic hydrocarbon (PAH) residuals to penetrate the membrane and enter the mass spectrometer as they evaporated from the sample. Using this simple setup we were able to quantitatively (approximately 10% relative standard deviation (RSD)) detect PAHs with up to five aromatic rings and with detection limits in the low parts-per-million (ppm) range. The vial system solves one of the major difficulties in analysis of larger PAHs using a MIMS. Normally, analysis of PAHs with more than two rings is hampered by a long memory effect due to the sticking of the PAHs to the inlet system, the membrane and surfaces in the vacuum system. By removing the vial from the sample cell within 2 min, we were able to analyze samples at 5-10 min intervals. The preliminary laboratory experiments presented here show much promise with respect to the development of a hand held (<10 kg) on-site mass spectrometry system for PAH screening at contaminated sites.
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Affiliation(s)
- Helle Frandsen
- Department of Chemistry, Copenhagen University, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
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Liu X, Nacson S, Grigoriev A, Lynds P, Pawliszyn J. A new thermal desorption solid-phase microextraction system for hand-held ion mobility spectrometry. Anal Chim Acta 2006. [DOI: 10.1016/j.aca.2005.12.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Mulligan CC, Justes DR, Noll RJ, Sanders NL, Laughlin BC, Cooks RG. Direct monitoring of toxic compounds in air using a portable mass spectrometer. Analyst 2006; 131:556-67. [PMID: 16568173 DOI: 10.1039/b517541k] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A portable tandem mass spectrometer, capable of performing atmospheric pressure chemical ionization (APCI) using a direct atmospheric inlet, is applied to the real-time monitoring of toxic compounds in air. Analytes of interest include dimethyl methylphosphonate, arsine, benzene, toluene, pyridine and vinyl acetate. The detection, identification and quantification of organic and inorganic compounds in air is demonstrated using short analysis times (<5 seconds) with detection limits in the low ppb (v/v) levels and linear dynamic ranges of several orders of magnitude. Highly specific detection and identification is achieved, even when the analyte is a trace component in a complex mixture including such interferents as fuels, lubricants, and cleaners. The effects of environmental conditions, including temperature and humidity, are delineated. Receiver operating characteristic (ROC) curves are presented to show the trade-off between false positive and false negative detection rates. Tandem mass spectrometry based both on collision-induced dissociation and on selective atmospheric pressure ion/molecule reactions is also used to increase selectivity and sensitivity.
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Thompson AJ, Creba AS, Ferguson RM, Krogh ET, Gill CG. A coaxially heated membrane introduction mass spectrometry interface for the rapid and sensitive on-line measurement of volatile and semi-volatile organic contaminants in air and water at parts-per-trillion levels. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2006; 20:2000-8. [PMID: 16770756 DOI: 10.1002/rcm.2551] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A coaxially heated membrane introduction mass spectrometry (MIMS) sampling interface is presented that demonstrates improved on-line performance for the direct measurement of semi-volatile organic compounds (SVOCs) in air and water samples at parts-per-trillion levels. The device is based on a polydimethylsiloxane (PDMS) capillary hollow fibre membrane (HFM) in a pneumatically assisted "flow-over" configuration that is resistively heated on the membrane interior via a coaxial nichrome wire, establishing a thermal gradient counter to the analyte concentration gradient. This arrangement allows for continuous and/or pulsed heating modes, affording excellent sensitivity for the on-line measurement of SVOCs while retaining sensitivity for volatile organic compounds (VOCs). In addition, the signal response time for SVOCs is reduced substantially over conventional "flow-over" MIMS interfaces. Separation and quantitation of analytes are achieved using quadrupole ion trap tandem mass spectrometry.
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Affiliation(s)
- Alexander J Thompson
- Applied Environmental Research Laboratories, Department of Chemistry, Malaspina University-College, 900 Fifth Street, Nanaimo, British Columbia, Canada, V9R 5S5
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