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Elkabets O, Neumark B, Amirav A. Fast saliva analysis by GC-MS with Cold EI and Open Probe Fast GC-MS with Cold EI for the detection of cannabis usage. JOURNAL OF MASS SPECTROMETRY : JMS 2023; 58:e4981. [PMID: 37950648 DOI: 10.1002/jms.4981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/03/2023] [Accepted: 10/11/2023] [Indexed: 11/13/2023]
Abstract
Saliva is a body fluid that is much easier to collect and analyze than blood. Thus, saliva analysis for the detection of delta 9-tetrahydrocannabinol (delta 9-THC) can serve as a tool for law enforcement agents to detect cannabis consumption by drivers. Fast saliva analysis for the presence of delta 9-THC and/or cannabidiol (CBD) is described with both gas chromatography-mass spectrometry (GC-MS) with Cold electron ionization (EI) with good separation and in 10 min and/or with Open Probe Fast GC-MS with Cold EI in under 1 min full analysis cycle time. Saliva was taken directly from donors' tongues on a thin glass rod that was used "as is" for analysis. The saliva was thermally desorbed with a modified ChromatoProbe device inside the gas chromatograph (GC) injector and in an Open Probe (Agilent name QuickProbe) for its sub-1-min analysis. Cold EI is based on coupling of the GC and mass spectrometer (MS) with a supersonic molecular beam and on EI of vibrationally cold sample molecules during their flight through a contact-free ion source (thereby named Cold EI). A revised type of Open Probe Fast GC-MS on the bench is also described. Our saliva analysis was characterized by: Saliva can be collected in the field and transported to the lab for analyses "as is" without any sample preparation. Easy detection of cannabis consumption from cigarettes and/or other cannabis products. Distinction between the isomers delta 9-THC and CBD. Ultra-fast analysis in under 1 min using Open Probe Fast GC-MS with Cold EI.
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Affiliation(s)
- Oneg Elkabets
- School of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Benny Neumark
- School of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Aviv Amirav
- School of Chemistry, Tel Aviv University, Tel Aviv, Israel
- Aviv Analytical Ltd, Hod Hasharon, Israel
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2
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Dolgushev PA, Shashkov MV. High-Temperature Two-Dimensional Gas Chromatography with Flow Modulator for Analyzing Complex Objects of Catalytic Processing. Chromatographia 2023. [DOI: 10.1007/s10337-022-04210-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
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3
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Cai H, Stearns SD. A fast temperature-programmed second-dimension column for comprehensive two-dimensional gas chromatography. Anal Bioanal Chem 2022; 415:2435-2446. [PMID: 36449031 DOI: 10.1007/s00216-022-04443-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/11/2022] [Accepted: 11/16/2022] [Indexed: 12/03/2022]
Abstract
The short analysis time and constant temperature environment in the second dimension of two-dimensional comprehensive chromatography frequently causes wraparound problems, especially for complex high boilers. This problem can be solved by temperature programming on the second column, but since this requires heating and cooling the column in a matter of seconds, it is difficult to implement. In this study, we describe a method of accomplishing rapid heating and cooling with a resistively heated column cooled by compressed air. Critical to this method is minimizing the lag time between the actual temperature and the reported temperature by using the column heating element as the temperature sensor, virtually eliminating the danger of overshooting the temperature setpoint. This technique facilitates a ramp rate of up to 100 °C/s with minimal overshooting-well beyond the requirements of gas chromatography. A single-layer column bundle design allows a compressed-air cooling device to cool the column from 200 to 50 °C at an average rate of -21 °C/s. The secondary dimension temperature programming is facilitated by the longer secondary dimension time made possible by the direct flow modulation method. We evaluated the performance of the single-layer column bundle and demonstrated this method by applying it to a gasoline sample. We also compared this method with the traditional isothermal approach and found that use of the secondary temperature program reduced the naphthalene retention time from 12.1 to 6.3 s and its peak width at half height from 846 to 126 ms.
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Affiliation(s)
- Huamin Cai
- Valco Instruments Co. Inc., 8300 Waterbury Dr., Houston, TX, 77055, USA.
| | - Stanley D Stearns
- Valco Instruments Co. Inc., 8300 Waterbury Dr., Houston, TX, 77055, USA
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4
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Neumark B, Elkabets O, Shefer G, Buch A, Stern N, Amirav A. Whole blood analysis for medical diagnostics by GC-MS with Cold EI. JOURNAL OF MASS SPECTROMETRY : JMS 2022; 57:e4873. [PMID: 35796286 PMCID: PMC9540862 DOI: 10.1002/jms.4873] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 06/19/2022] [Accepted: 06/26/2022] [Indexed: 06/15/2023]
Abstract
This study covers a new method and related instrumentation for whole blood analysis for medical diagnostics. Two-μL whole blood samples were collected using "minimal invasive" diabetes lancet and placed on a thin glass rod mounted on a newly designed BloodProbe. The BloodProbe with the whole blood sample was inserted directly into a ChromatoProbe mounted on the GC inlet, and thus, no sample preparation was involved. The analysis was performed within 10 min using a GC-MS with Cold EI that is based on interfacing GC and MS with supersonic molecular beams (SMB) along with electron ionization of vibrationally cold sample compounds in the SMB (hence the name Cold EI). Our blood analysis revealed several observations: (1) Detailed mass chromatograms were generated with full range of all the nonpolar lipids in blood including fatty acids, cholesterol, cholesteryl esters, vitamin E, monoglycerides, diglycerides, and triglycerides. (2) The analysis of whole blood was found to be as informative as the conventional clinical analysis of blood serum. (3) Cholesteryl esters were more sensitive than free cholesterol alone to the effect of diet of obese people. (4) Major enhancement of several fatty acid methyl esters was found in the blood of a cancer patient with liver dysfunction. (5) Vitamin E as both α- and β-tocopherol was found with person-dependent ratio of these two compounds. (6) Elemental sulfur S8 was identified in blood. (7) Several drugs and other compounds were found and need further study of their correlation to medical issues.
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Affiliation(s)
- Benny Neumark
- School of ChemistryTel Aviv UniversityTel AvivIsrael
| | - Oneg Elkabets
- School of ChemistryTel Aviv UniversityTel AvivIsrael
| | - Gabi Shefer
- The Institute of Endocrinology, Metabolism and HypertensionTel‐Aviv Sourasky Medical CenterTel AvivIsrael
| | - Assaf Buch
- The Institute of Endocrinology, Metabolism and HypertensionTel‐Aviv Sourasky Medical CenterTel AvivIsrael
| | - Naftali Stern
- The Institute of Endocrinology, Metabolism and HypertensionTel‐Aviv Sourasky Medical CenterTel AvivIsrael
- The Sagol Center for Epigenetics of Aging and MetabolismTel‐Aviv Sourasky Medical CenterTel AvivIsrael
- Sackler Faculty of MedicineTel Aviv UniversityTel AvivIsrael
| | - Aviv Amirav
- School of ChemistryTel Aviv UniversityTel AvivIsrael
- Aviv AnalyticalHod HasharonIsrael
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5
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Fialkov AB, Lehotay SJ, Amirav A. Less than one minute low-pressure gas chromatography - mass spectrometry. J Chromatogr A 2019; 1612:460691. [PMID: 31759639 DOI: 10.1016/j.chroma.2019.460691] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/05/2019] [Accepted: 11/06/2019] [Indexed: 01/08/2023]
Abstract
Conventional gas chromatography - mass spectrometry (GC-MS) takes 20-40 min per sample, which is undesirably slow in any application if speed can be increased while still meeting analytical needs. In this study, we achieved reasonably good separations with full analysis cycle times of less than 1 min by combining for the first time low-pressure (LP) GC-MS with low thermal mass (LTM) resistive-heating for rapid temperature ramping and cooling of the capillary column. The analytical column is threaded into the LTM thin-walled metal tubing in an instrumental device known as "LTM Fast GC" that is mounted at the top of the gas chromatograph in a detector port. The column inlet and outlet are connected to the GC injector and MS transfer line as usual. For LPGC-MS, a 40 cm, 0.1 mm. i.d. uncoated flow restrictor capillary connected at the injector is coupled with a 2.6 m, 0.25 mm i.d., 0.25 µm film thickness analytical column leading to the MS. Thus, the inlet operates at normal GC pressures, but the analytical column is under vacuum, which increases the optimal helium carrier gas flow velocity thereby increasing speed of full range separations while maintaining acceptable quality of chromatography. This column configuration in LTM-LPGC-MS trades a 64-fold gain in speed of analysis vs. standard GC-MS for a 4-fold loss in chromatographic peak capacity, thereby converting analysis time from minutes into seconds in common applications. For example, jet fuel containing fatty acid methyl esters (akin to biofuel) was separated in 25 s with <1 min full analysis cycle time. An EPA Method 8270 mixture of 76 analytes was also analyzed in <1 min full cycle time by LTM-LPGC-MS. Other examples include very fast analysis of heroin in a street drug powder and elucidation of a new organic synthetic compound. In this report, we describe and discuss the several advantageous and practical features of LTM-LPGC-MS, as well as its trade-offs.
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Affiliation(s)
| | - Steven J Lehotay
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 10938, USA
| | - Aviv Amirav
- School of Chemistry, Tel Aviv University, Tel Aviv 69978, Israel; Aviv Analytical Ltd., 24 Hanagar Street, Hod Hasharon 4527713, Israel.
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Keshet U, Alon T, Fialkov AB, Amirav A. Open Probe fast GC-MS - combining ambient sampling ultra-fast separation and in-vacuum ionization for real-time analysis. JOURNAL OF MASS SPECTROMETRY : JMS 2017; 52:417-426. [PMID: 28455844 DOI: 10.1002/jms.3941] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/02/2017] [Accepted: 04/25/2017] [Indexed: 06/07/2023]
Abstract
An Open Probe inlet was combined with a low thermal mass ultra-fast gas chromatograph (GC), in-vacuum electron ionization ion source and a mass spectrometer (MS) of GC-MS for obtaining real-time analysis with separation. The Open Probe enables ambient sampling via sample vaporization in an oven that is open to room air, and the ultra-fast GC provides ~30-s separation, while if no separation is required, it can act as a transfer line with 2 to 3-s sample transfer time. Sample analysis is as simple as touching the sample, pushing the sample holder into the Open Probe oven and obtaining the results in 30 s. The Open Probe fast GC was mounted on a standard Agilent 7890 GC that was coupled with an Agilent 5977A MS. Open Probe fast GC-MS provides real-time analysis combined with GC separation and library identification, and it uses the low-cost MS of GC-MS. The operation of Open Probe fast GC-MS is demonstrated in the 30-s separation and 50-s full analysis cycle time of tetrahydrocannabinol and cannabinol in Cannabis flower, sub 1-min analysis of trace trinitrotoluene transferred from a finger onto a glass surface, vitamin E in canola oil, sterols in olive oil, polybrominated flame retardants in plastics, alprazolam in Xanax drug pill and free fatty acids and cholesterol in human blood. The extrapolated limit of detection for pyrene is <1 fg, but the concentration is too high and the software noise calculation is untrustworthy. The broad range of compounds amenable for analysis is demonstrated in the analysis of reserpine. The possible use with alternate standard GC-MS and Open Probe fast GC-MS is demonstrated in the analysis of heroin in its street drug powder. The use of Open Probe with the fast GC acting as a transfer line is demonstrated in <10-s analysis without separation of ibuprofen and estradiol. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- U Keshet
- School of Chemistry, Tel Aviv University, Tel Aviv, 69978, Israel
| | - T Alon
- School of Chemistry, Tel Aviv University, Tel Aviv, 69978, Israel
| | - A B Fialkov
- School of Chemistry, Tel Aviv University, Tel Aviv, 69978, Israel
| | - A Amirav
- School of Chemistry, Tel Aviv University, Tel Aviv, 69978, Israel
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7
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Fast Heroin and Cocaine Analysis by GC–MS with Cold EI: The Important Role of Flow Programming. Chromatographia 2017. [DOI: 10.1007/s10337-017-3249-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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8
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Fitz BD, Synovec RE. Extension of the two-dimensional mass channel cluster plot method to fast separations utilizing low thermal mass gas chromatography with time-of-flight mass spectrometry. Anal Chim Acta 2016; 913:160-70. [DOI: 10.1016/j.aca.2016.01.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 01/28/2016] [Accepted: 01/29/2016] [Indexed: 10/22/2022]
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9
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Fischer M, Wohlfahrt S, Varga J, Matuschek G, Saraji-Bozorgzad MR, Denner T, Walte A, Zimmermann R. Optically Heated Ultra-Fast-Cycling Gas Chromatography Module for Separation of Direct Sampling and Online Monitoring Applications. Anal Chem 2015; 87:8634-9. [DOI: 10.1021/acs.analchem.5b01879] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael Fischer
- Joint
Mass Spectrometry Centre, Institute of Chemistry, Chair of Analytical
Chemistry, University of Rostock, 18057 Rostock, Germany
- Joint
Mass Spectrometry Centre, Cooperation Group “Comprehensive
Molecular Analytics”, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Sebastian Wohlfahrt
- Joint
Mass Spectrometry Centre, Institute of Chemistry, Chair of Analytical
Chemistry, University of Rostock, 18057 Rostock, Germany
- Joint
Mass Spectrometry Centre, Cooperation Group “Comprehensive
Molecular Analytics”, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Janos Varga
- Joint
Mass Spectrometry Centre, Cooperation Group “Comprehensive
Molecular Analytics”, Helmholtz Zentrum München, 85764 Neuherberg, Germany
- University of Augsburg, Chair of Resource Strategy, 86159 Augsburg, Germany
| | - Georg Matuschek
- Joint
Mass Spectrometry Centre, Cooperation Group “Comprehensive
Molecular Analytics”, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | | | | | | | - Ralf Zimmermann
- Joint
Mass Spectrometry Centre, Institute of Chemistry, Chair of Analytical
Chemistry, University of Rostock, 18057 Rostock, Germany
- Joint
Mass Spectrometry Centre, Cooperation Group “Comprehensive
Molecular Analytics”, Helmholtz Zentrum München, 85764 Neuherberg, Germany
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10
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Affiliation(s)
- Peter Boeker
- Institute
of Agricultural
Engineering, University of Bonn, Nussallee 5, D-53115 Bonn, North Rhine-Westphalia, Germany
| | - Jan Leppert
- Institute
of Agricultural
Engineering, University of Bonn, Nussallee 5, D-53115 Bonn, North Rhine-Westphalia, Germany
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11
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Fitz BD, Mannion BC, To K, Hoac T, Synovec RE. Evaluation of injection methods for fast, high peak capacity separations with low thermal mass gas chromatography. J Chromatogr A 2015; 1392:82-90. [DOI: 10.1016/j.chroma.2015.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 10/23/2022]
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12
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Jacobs MR, Hilder EF, Shellie RA. Applications of resistive heating in gas chromatography: A review. Anal Chim Acta 2013; 803:2-14. [DOI: 10.1016/j.aca.2013.04.063] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 04/25/2013] [Accepted: 04/27/2013] [Indexed: 11/28/2022]
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13
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Direct analysis of intact glycidyl fatty acid esters in edible oils using gas chromatography–mass spectrometry. J Chromatogr A 2013; 1313:202-11. [DOI: 10.1016/j.chroma.2013.06.056] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 06/20/2013] [Accepted: 06/20/2013] [Indexed: 11/22/2022]
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14
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Wang A, Tolley HD, Lee ML. Gas chromatography using resistive heating technology. J Chromatogr A 2012; 1261:46-57. [DOI: 10.1016/j.chroma.2012.05.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/03/2012] [Accepted: 05/05/2012] [Indexed: 11/15/2022]
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15
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Amirav A, Gordin A, Hagooly Y, Rozen S, Belgorodsky B, Seemann B, Marom H, Gozin M, Fialkov AB. Measurement and optimization of organic chemical reaction yields by GC–MS with supersonic molecular beams. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.05.031] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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