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Yan D, Tedone L, Koutoulis A, Whittock SP, Shellie RA. Parallel comprehensive two-dimensional gas chromatography. J Chromatogr A 2017; 1524:202-209. [DOI: 10.1016/j.chroma.2017.09.063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 09/25/2017] [Accepted: 09/25/2017] [Indexed: 10/18/2022]
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2
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Ntlhokwe G, Tredoux AGJ, Górecki T, Edwards M, Vestner J, Muller M, Erasmus L, Joubert E, Christel Cronje J, de Villiers A. Analysis of honeybush tea (Cyclopia spp.) volatiles by comprehensive two-dimensional gas chromatography using a single-stage thermal modulator. Anal Bioanal Chem 2017; 409:4127-4138. [DOI: 10.1007/s00216-017-0360-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 03/17/2017] [Accepted: 04/03/2017] [Indexed: 11/29/2022]
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3
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Sgorbini B, Cagliero C, Boggia L, Liberto E, Reichenbach SE, Rubiolo P, Cordero C, Bicchi C. Parallel dual secondary-column-dual detection comprehensive two-dimensional gas chromatography: a flexible and reliable analytical tool for essential oils quantitative profiling. FLAVOUR FRAG J 2015. [DOI: 10.1002/ffj.3255] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Barbara Sgorbini
- Dipartimento di Scienza e Tecnologia del Farmaco; Università degli Studi di Torino; Via Pietro Giuria 9 I-10125 Torino Italy
| | - Cecilia Cagliero
- Dipartimento di Scienza e Tecnologia del Farmaco; Università degli Studi di Torino; Via Pietro Giuria 9 I-10125 Torino Italy
| | - Lorenzo Boggia
- Dipartimento di Scienza e Tecnologia del Farmaco; Università degli Studi di Torino; Via Pietro Giuria 9 I-10125 Torino Italy
| | - Erica Liberto
- Dipartimento di Scienza e Tecnologia del Farmaco; Università degli Studi di Torino; Via Pietro Giuria 9 I-10125 Torino Italy
| | - Stephen E. Reichenbach
- Computer Science and Engineering Department; University of Nebraska; 260 Avery Hall Lincoln NE 68588-0115 USA
| | - Patrizia Rubiolo
- Dipartimento di Scienza e Tecnologia del Farmaco; Università degli Studi di Torino; Via Pietro Giuria 9 I-10125 Torino Italy
| | - Chiara Cordero
- Dipartimento di Scienza e Tecnologia del Farmaco; Università degli Studi di Torino; Via Pietro Giuria 9 I-10125 Torino Italy
| | - Carlo Bicchi
- Dipartimento di Scienza e Tecnologia del Farmaco; Università degli Studi di Torino; Via Pietro Giuria 9 I-10125 Torino Italy
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4
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Nnaji CN, Williams KC, Bishop JM, Verbeck GF. Hydrogen as a GC/MS carrier and buffer gas for use in forensic laboratories. Sci Justice 2015; 55:162-7. [PMID: 25934367 DOI: 10.1016/j.scijus.2015.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 10/24/2022]
Abstract
A custom set of ion volumes was manufactured in order to investigate the gain and byproducts using hydrogen as a buffer gas following electron ionization in a quadrupole ion trap mass spectrometer as compared with helium. Analyses of illicit drugs such as cocaine, codeine, and oxycodone, and explosives such as TNT, RDX, and HMTD with ion volume exit orifices of 1mm, 2mm, 4mm, 6mm, 8mm and 10mm were performed using GC/MS. Strong similarities between hydrogen and helium spectra of illicit drugs and explosives provide evidence that hydrogen can be used effectively as a buffer gas in an ion trap mass spectrometer.
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Affiliation(s)
- Chinyere N Nnaji
- Department of Chemistry, University of North Texas, Denton, TX 76201, USA
| | | | - Jonathan M Bishop
- Department of Chemistry, University of North Texas, Denton, TX 76201, USA
| | - Guido F Verbeck
- Department of Chemistry, University of North Texas, Denton, TX 76201, USA.
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5
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Nicolotti L, Cordero C, Bressanello D, Cagliero C, Liberto E, Magagna F, Rubiolo P, Sgorbini B, Bicchi C. Parallel dual secondary column-dual detection: A further way of enhancing the informative potential of two-dimensional comprehensive gas chromatography. J Chromatogr A 2014; 1360:264-74. [DOI: 10.1016/j.chroma.2014.07.081] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 07/22/2014] [Accepted: 07/24/2014] [Indexed: 01/19/2023]
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6
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Urinary metabolic fingerprinting of mice with diet-induced metabolic derangements by parallel dual secondary column-dual detection two-dimensional comprehensive gas chromatography. J Chromatogr A 2014; 1361:265-76. [DOI: 10.1016/j.chroma.2014.08.015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 07/31/2014] [Accepted: 08/04/2014] [Indexed: 12/19/2022]
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7
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Comprehensive two-dimensional gas chromatography under high outlet pressure conditions: a new approach to correct the flow-mismatch issue in the two dimensions. J Chromatogr A 2014; 1332:57-63. [PMID: 24513348 DOI: 10.1016/j.chroma.2014.01.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/15/2014] [Accepted: 01/16/2014] [Indexed: 11/22/2022]
Abstract
The typical column sets employed in comprehensive two-dimensional gas chromatography (GC × GC) suffer from the impossibility to fully exploit the efficiency of both dimensions simultaneously. Adding a restrictor at the end of the second dimension is a possible approach to adjust the linear velocity profile. Under these high outlet pressure conditions the second dimension becomes much slower while the effect on the primary column is limited. The gap in terms of optimum inlet pressures is thus reduced. A program written in Microsoft Excel was used to calculate the efficiencies of the two dimensions in GC × GC at different outlet pressures. A GC × GC set-up with a restrictor at the end of the second dimension column was successfully installed. Experiments proved that this is a possible way to have a better exploitation of the columns. The chromatograms obtained for a number of applications confirm that the separations achieved at elevated outlet pressure are more efficient than those obtained with the same column set under atmospheric outlet conditions. The price to pay is that the separations become considerably slower.
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8
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Tranchida PQ, Zoccali M, Franchina FA, Cotroneo A, Dugo P, Mondello L. Gas velocity at the point of re-injection: An additional parameter in comprehensive two-dimensional gas chromatography optimization. J Chromatogr A 2013; 1314:216-23. [DOI: 10.1016/j.chroma.2013.09.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 10/26/2022]
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9
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Peroni D, Vonk RJ, van Egmond W, Janssen HG. Macroporous polymer monoliths as second dimension columns in comprehensive two-dimensional gas chromatography: A feasibility study. J Chromatogr A 2012; 1268:139-49. [DOI: 10.1016/j.chroma.2012.10.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2012] [Revised: 10/05/2012] [Accepted: 10/08/2012] [Indexed: 10/27/2022]
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10
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Determination of Trace Levels of Fatty Acid Methyl Esters in Aviation Fuel by GC × GC–FID and Comparison with the Reference GC–MS Method. Chromatographia 2012. [DOI: 10.1007/s10337-012-2320-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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11
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Tranchida PQ, Zoccali M, Franchina FA, Dugo P, Mondello L. Measurement of fundamental chromatography parameters in conventional and split-flow comprehensive two-dimensional gas chromatography-mass spectrometry: A focus on the importance of second-dimension injection efficiency. J Sep Sci 2012; 36:212-8. [PMID: 23034883 DOI: 10.1002/jssc.201200592] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 07/26/2012] [Accepted: 07/26/2012] [Indexed: 11/12/2022]
Abstract
The present manuscript reports a comparative study between conventional and split-flow comprehensive GC×GC-MS. Conventional GC×GC-MS was performed by using a single GC oven, and with a widely employed apolar (30 m × 0.25 mm id)-polar (1 m × 0.10 mm id) column combination. Split-flow GC×GC-MS experiments were carried out by using the same first and second analytical columns, and by diverting part of the primary-capillary flow to waste, via a waste line. The latter was located at the conjunction point between the two dimensions. The measurement of fundamental gas chromatography parameters (efficiency, resolution), in both dimensions and under different experimental conditions, enabled the attainment of detailed information related to GC×GC-MS method optimization. Finally, the results derived from the present investigation highlight an important GC×GC issue, namely the efficiency of band reinjection onto the second-dimension capillary.
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Affiliation(s)
- Peter Quinto Tranchida
- Dipartimento Farmaco-Chimico, Facoltà di Farmacia, Università degli Studi di Messina, Messina, Italy
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12
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Mostafa A, Edwards M, Górecki T. Optimization aspects of comprehensive two-dimensional gas chromatography. J Chromatogr A 2012; 1255:38-55. [DOI: 10.1016/j.chroma.2012.02.064] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 02/21/2012] [Accepted: 02/24/2012] [Indexed: 11/16/2022]
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13
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Arsene C, Vione D, Grinberg N, Olariu RI. GC × GC-MS HYPHENATED TECHNIQUES FOR THE ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN AIR. J LIQ CHROMATOGR R T 2011. [DOI: 10.1080/10826076.2011.587749] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Cecilia Arsene
- a Faculty of Chemistry, Laboratory of Analytical Chemistry, “Al. I. Cuza” University of Iasi , Iasi, Romania
| | - Davide Vione
- b Dipartimento di Chimica Analitica , Università di Torino , Torino, Italy
- c Centro Interdipartimentale NatRisk, Università di Torino , Grugliasco (TO), Italy
| | - Nelu Grinberg
- d Boehringer Ingelheim Pharmaceuticals Inc. , Ridgefield, Connecticut, USA
| | - Romeo Iulian Olariu
- a Faculty of Chemistry, Laboratory of Analytical Chemistry, “Al. I. Cuza” University of Iasi , Iasi, Romania
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14
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Factors affecting peak shape in comprehensive two-dimensional gas chromatography with non-focusing modulation. J Chromatogr A 2011; 1218:3153-8. [DOI: 10.1016/j.chroma.2010.08.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2010] [Revised: 08/09/2010] [Accepted: 08/11/2010] [Indexed: 11/18/2022]
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15
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Tistaert C, Dejaegher B, Heyden YV. Chromatographic separation techniques and data handling methods for herbal fingerprints: A review. Anal Chim Acta 2011; 690:148-61. [DOI: 10.1016/j.aca.2011.02.023] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 02/04/2011] [Accepted: 02/09/2011] [Indexed: 10/18/2022]
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16
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Optimized use of a 50 μm ID secondary column in comprehensive two-dimensional gas chromatography–mass spectrometry. J Chromatogr A 2010; 1217:4160-6. [DOI: 10.1016/j.chroma.2010.01.040] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 12/23/2009] [Accepted: 01/13/2010] [Indexed: 11/18/2022]
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17
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Tranchida PQ, Purcaro G, Conte L, Dugo P, Dugo G, Mondello L. Optimized Use of a 50 μm Internal Diameter Secondary Column in a Comprehensive Two-Dimensional Gas Chromatography System. Anal Chem 2009; 81:8529-37. [DOI: 10.1021/ac901461y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter Quinto Tranchida
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, I-98168, Messina, Italy, Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, via Sondrio 2, 33100, Udine, Italy, and Campus-Biomedico, Via Alvaro del Portillo, 21, 00128 Roma, Italy
| | - Giorgia Purcaro
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, I-98168, Messina, Italy, Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, via Sondrio 2, 33100, Udine, Italy, and Campus-Biomedico, Via Alvaro del Portillo, 21, 00128 Roma, Italy
| | - Lanfranco Conte
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, I-98168, Messina, Italy, Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, via Sondrio 2, 33100, Udine, Italy, and Campus-Biomedico, Via Alvaro del Portillo, 21, 00128 Roma, Italy
| | - Paola Dugo
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, I-98168, Messina, Italy, Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, via Sondrio 2, 33100, Udine, Italy, and Campus-Biomedico, Via Alvaro del Portillo, 21, 00128 Roma, Italy
| | - Giovanni Dugo
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, I-98168, Messina, Italy, Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, via Sondrio 2, 33100, Udine, Italy, and Campus-Biomedico, Via Alvaro del Portillo, 21, 00128 Roma, Italy
| | - Luigi Mondello
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, I-98168, Messina, Italy, Dipartimento di Scienze degli Alimenti, Università degli Studi di Udine, via Sondrio 2, 33100, Udine, Italy, and Campus-Biomedico, Via Alvaro del Portillo, 21, 00128 Roma, Italy
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18
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Enhanced resolution comprehensive two-dimensional gas chromatography applied to the analysis of roasted coffee volatiles. J Chromatogr A 2009; 1216:7301-6. [PMID: 19596333 DOI: 10.1016/j.chroma.2009.06.056] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 06/10/2009] [Accepted: 06/17/2009] [Indexed: 11/22/2022]
Abstract
The present research is based on the full exploitation of the separation power of a 0.05 mm internal diameter (ID) capillary, as a comprehensive two-dimensional (2D) GC (GC x GC) secondary column, with the objective of attaining very high-resolution second dimension separations. The aim was achieved by using a split-flow system developed in previous research [P.Q. Tranchida, A. Casilli, P. Dugo, G. Dugo, L. Mondello, Anal. Chem. 79 (2007) 2266], and a dual-oven GC x GC instrument. The column combination employed consisted of a polar 30 m x 0.25 mm ID column connected, by means of a T union, to a detector-linked high-resolution 1.1 m x 0.05 mm ID apolar analytical column and to a 0.33 m x 0.05 mm ID retention gap; the latter was connected to a manually operated split valve. As previously demonstrated, the use of a split valve enables the regulation of gas flows through both analytical columns, generating the most appropriate gas linear velocities. Comprehensive 2D GC experiments were carried out on Arabica roasted coffee volatiles (previously extracted by means of solid-phase microextraction) with the split-valve closed (equal to what can be defined as conventional GC x GC) and with the split-valve opened at various degrees. The reasons why it is absolutely not effective to use a 0.05 mm ID column as second dimension in a conventional GC x GC instrument will be discussed and demonstrated. On the contrary, the use of a 0.05 mm ID column as second dimension, under ideal conditions in a split-flow, twin-oven system, will also be illustrated and discussed.
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19
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Chapter 9 Volatile Components of Plants, Essential Oils, and Fragrances. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s0166-526x(09)05509-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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20
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Chapter 10 Analysis of Food Constituents. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s0166-526x(09)05510-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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21
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Recent developments in the application of comprehensive two-dimensional gas chromatography. J Chromatogr A 2008; 1186:67-108. [DOI: 10.1016/j.chroma.2008.01.002] [Citation(s) in RCA: 298] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2007] [Revised: 01/01/2008] [Accepted: 01/02/2008] [Indexed: 11/23/2022]
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22
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Mondello L, Tranchida PQ, Dugo P, Dugo G. Comprehensive two-dimensional gas chromatography-mass spectrometry: a review. MASS SPECTROMETRY REVIEWS 2008; 27:101-124. [PMID: 18240151 DOI: 10.1002/mas.20158] [Citation(s) in RCA: 240] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Although comprehensive two-dimensional gas chromatography (GC x GC) has been on the scene for more than 15 years, it is still generally considered a relatively novel technique and is yet far from being fully established. The revolutionary aspect of GC x GC, with respect to classical multidimensional chromatography, is that the entire sample is subjected to two distinct analytical separations. The resulting enhanced separating capacity makes this approach a prime choice when GC analysts are challenged with highly complex mixtures. The combination of a third mass spectrometric dimension to a GC x GC system generates the most powerful analytical tool today for volatile and semi-volatile analytes. The present review is focused on the rather brief, but not scant, history of comprehensive two-dimensional GC-MS: the first experiments were carried out at the end of the 1990s and, since then, the methodology has been increasingly studied and applied. Almost all GC x GC-MS applications have been carried out by using either a time-of-flight or quadrupole mass analyzer; significant experiments relative to a variety of research fields, as well as advantages and disadvantages of the MS systems employed, are discussed. The principles, practical and theoretical aspects, and the most significant developments of GC x GC are also described.
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Affiliation(s)
- Luigi Mondello
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, 98168 Messina, Italy.
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23
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Mondello L, Casilli A, Tranchida PQ, Lo Presti M, Dugo P, Dugo G. Comprehensive gas chromatography coupled to mass spectrometry for the separation of pesticides in a very complex matrix. Anal Bioanal Chem 2007; 389:1755-63. [PMID: 17589835 DOI: 10.1007/s00216-007-1412-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 05/18/2007] [Accepted: 05/31/2007] [Indexed: 11/28/2022]
Abstract
The present research is focused on the development of a comprehensive two-dimensional gas chromatography-rapid scanning quadrupole mass spectrometric (GC x GC-qMS) methodology for the analysis of trace-amount pesticides contained in a complex real-world sample. Reliable peak assignment was carried out by using a recently developed, dedicated pesticide MS library (for comprehensive GC analysis), characterized by a twin-filter search procedure, the first based on a minimum degree of spectral similarity and the second on the interactive use of linear retention indices (LRI). The library was constructed by subjecting mixtures of commonly used pesticides to GC x GC-qMS analysis and then deriving their pure mass spectra and LRI values. In order to verify the effectiveness of the approach, a pesticide-contaminated red grapefruit extract was analysed. The certainty of peak assignment was attained by exploiting both the enhanced separation power of dual-oven GC x GC and the highly effective search procedure.
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Affiliation(s)
- Luigi Mondello
- Dipartimento Farmaco-chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, 98168 Messina, Italy.
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24
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Eiceman GA, Gardea-Torresdey J, Dorman F, Overton E, Bhushan A, Dharmasena HP. Gas chromatography. Anal Chem 2007; 78:3985-96. [PMID: 16771536 DOI: 10.1021/ac060638e] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gary A Eiceman
- Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico 88003-0001, USA
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25
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Adam F, Bertoncini F, Brodusch N, Durand E, Thiébaut D, Espinat D, Hennion MC. New benchmark for basic and neutral nitrogen compounds speciation in middle distillates using comprehensive two-dimensional gas chromatography. J Chromatogr A 2007; 1148:55-64. [PMID: 17379235 DOI: 10.1016/j.chroma.2007.01.142] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2006] [Revised: 01/03/2007] [Accepted: 01/24/2007] [Indexed: 11/28/2022]
Abstract
This paper reports an analytical method for the comprehensive two-dimensional gas chromatography (GC x GC) separation and identification of nitrogen compounds (N-compounds) in middle distillates according to their types (basicity). For the evaluation of the best chromatographic conditions, a non-polar x polar approach was chosen. The impact of the second dimension (stationary phase and column length) on the separation of basic and neutral N-compounds was evaluated by mean of two-dimensional resolution. This study revealed that the implementation of polar secondary column having free electron pairs improves drastically the separation of N-compounds. Indeed, the presence of permanent dipole-permanent dipole interactions between neutral N-compounds and the stationary phase was enlightened. The comparison of two different nitrogen chemiluminescence detectors (NCD) was also evaluated for GC x GC selective monitoring of N-compounds. Owing to higher resolution power and enhanced sensitivity achieved using developed chromatographic and detection conditions, it was possible to identify univocally and to quantitate N-compounds (i) by class of compounds and (ii), within a class, by carbon number. Finally, quantitative comparison of GC x GC-NCD with conventional gas chromatography illustrates the benefits of GC x GC leading to an excellent correlation with results obtained by American Society for Testing Materials (ASTM) methods for the determination of basic/neutral nitrogen ratio in diesel samples.
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Affiliation(s)
- Frédérick Adam
- Institut Français du Pétrole, BP3, 69390 Vernaison, France
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26
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Tranchida PQ, Casilli A, Dugo P, Dugo G, Mondello L. Generation of Improved Gas Linear Velocities in a Comprehensive Two-Dimensional Gas Chromatography System. Anal Chem 2007; 79:2266-75. [PMID: 17288460 DOI: 10.1021/ac0618066] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A comprehensive two-dimensional gas chromatography (GC x GC) system (for convenience defined as "split flow" GC x GC), which may be operated at improved gas linear velocities in both dimensions, has been developed. The setup is formed of an apolar 30 m x 0.25 mm i.d. column connected, by means of a Y press fit, to a detector-linked 1 m x 0.1 mm i.d. polar analytical column, which passes through the (cryogenic) modulator, and to a 0.3 m x 0.1 mm i.d. retention gap, which is connected to a manually operated split valve. The latter enables the regulation of gas flows through the second analytical column [e.g., 60:40 (FID) ratio, 50:50 ratio, 40:60 (FID) ratio, etc.], in order to generate the most appropriate gas linear velocity, which is related to each specific analysis. In the pre-sent investigation, two sets of traditional and split flow GC x GC analyses were carried out on a cod liver oil fatty acid methyl ester sample by using the same temperature programs [180-250 degrees C at (a) 3 degrees C/min and at (b) 1.3 degrees C/min] and at an average first-dimension linear velocity of approximately 35.0 cm/s; thus, primary column retention times (and therefore elution temperatures) were essentially maintained. The second-dimension linear velocity was calculated to be approximately 333 cm/s in the traditional applications, while it was split valve-regulated until the most appropriate values [(a) approximately 213 cm/s; (b) approximately 264 cm/s] were attained in the alternative applications. Substantial improvements were observed and measured in the chromatography along the y-axis, while the contour plot chemical class structure was maintained.
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Affiliation(s)
- Peter Quinto Tranchida
- Dipartimento Farmaco-Chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, 98168-Messina, Italy
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27
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d'Acampora Zellner B, Casilli A, Dugo P, Dugo G, Mondello L. Odour fingerprint acquisition by means of comprehensive two-dimensional gas chromatography-olfactometry and comprehensive two-dimensional gas chromatography/mass spectrometry. J Chromatogr A 2007; 1141:279-86. [PMID: 17207489 DOI: 10.1016/j.chroma.2006.12.035] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2006] [Revised: 12/04/2006] [Accepted: 12/08/2006] [Indexed: 11/27/2022]
Abstract
The analysis of complex matrices, such as perfumes, by means of gas chromatography-olfactometry (GC-O) can be rather imprecise due to the co-elutions, leading to a possible masking of odour-active trace-level compounds by major interferences or agglomeration of olfactive impressions resulting in unreliable olfactive characterization. To overcome these limits an innovative technique, comprehensive two-dimensional gas chromatography-olfactometry (GC x GC-O), was applied, revealing several relevant co-elutions, as in the linalool and linalyl acetate zones. A total of 177 compounds, out of these 135 odour-active, were detected by GC-O, while about 481 out of 818 compounds presented odour-activity through GC x GC-O analyses. In addition, GC/mass spectrometry (GC/MS) and GC x GC/MS analyses were also performed. Peak assignment was achieved by means of different information sources, such as GC/MS, GC x GC/MS, LRI, injection of standards and olfactive impressions.
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Affiliation(s)
- Barbara d'Acampora Zellner
- Dipartimento Farmaco-Chimico, Facoltà di Farmacia, Università di Messina, viale Annunziata, 98168 Messina, Italy
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Adahchour M, Beens J, Vreuls R, Brinkman U. Recent developments in comprehensive two-dimensional gas chromatography (GC×GC). Trends Analyt Chem 2006. [DOI: 10.1016/j.trac.2006.03.002] [Citation(s) in RCA: 227] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
One of the challenges in performing comprehensive two-dimensional gas chromatographic separations is being able to predict the average linear velocities of the carrier gas in the two columns, especially when they have different diameters. The problem is compounded for loop-type modulators, where two thermal trapping zones that switch from hot to cold and back simultaneously are separated by a delay loop. If the linear velocity in the loop is not tuned to the length of the loop and the modulation period, the dual-stage modulation may cease to work properly. A model has been developed that calculates the flow rates in the columns and predicts appropriate delay loop dimensions for a given set-up. Additionally, the model determines the pressure ramp that needs to be used in order to maintain constant average linear velocity within the modulator loop throughout the course of the separation.
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Affiliation(s)
- James Harynuk
- Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ont, Canada
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Affiliation(s)
- Carolyn J Koester
- Forensic Science Center, Technical Information Department, Lawrence Livermore National Laboratory, Livermore, California 94551-0808, USA
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