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New Analytical Method for Determination of Phthalates in Wastewater by on Line LC-GC-MS Using the TOTAD Interface and Fraction Collector. Processes (Basel) 2021. [DOI: 10.3390/pr9060920] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
There is an increasing demand for automatic, reliable and sensitive analytical methods for determining trace levels of phthalic acid esters (PAEs) in environmental samples. While on line coupled liquid chromatography-gas chromatography (LC-GC) has been proof to be a powerful tool for trace-level analyses in complex matrices, the present work presents a new totally automated on line LC-GC method, using the Through Oven Transfer Adsorption Desorption (TOTAD) interface, for the analysis of four of the main phthalates, dibuthyl phthalate (DBP), diethyl phthalate (DEP), dimethyl phthalate (DMP) and diethylhexyl phthalate (DEHP), in a matrix as complex as leachate. The sample is directly injected into the LC injector valve with no sample pretreatment other than simple filtration. The LC step separates the target analytes from matrix interference. Two different LC fractions are collected in a purposely designed fraction collector and then transferred to the TOTAD interface, which concentrates the analytes, totally eliminates the solvent and transfers the analytes to the GC-MS system, where the analysis is carried out. The LOD of the method varied from 0.1 µg/L (DEHP) to 1.4 µg/L (DMP), RSD for retention time below 0.14% and for absolute peak areas below 12% and linearity from 1 µg/L to 1000 µg/L (R2 > 0.99), except in the case of DEHP (linearity from 1 to 250 µg/L, R2 = 0.94). The method was applied to the analysis of the target analytes in samples collected from a municipal solid waste (MSW) landfill in Rosario (Argentina).
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Zoccali M, Salerno TMG, Tranchida PQ, Mondello L. Use of a low-cost, lab-made Y-interface for liquid-gas chromatography coupling for the analysis of mineral oils in food samples. J Chromatogr A 2021; 1648:462191. [PMID: 34000596 DOI: 10.1016/j.chroma.2021.462191] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/02/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022]
Abstract
Consumers are daily exposed to a range of mineral oil hydrocarbons via food consumption. Major sources of MOH in food are packaging and additives, processing aids, and lubricants. In 2019, an EU guidance was released covering specific directions for sampling and analysis of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in food and food contact materials within the frame of Recommendation (EU) 2017/84 for the monitoring of mineral oils. The parameters required by the guide are increasingly stringent, and coping with this type of analysis is now very challenging. It is within such a context that the present research is confined, inasmuch that it is focused on the construction of a low-cost, lab-made Y-interface for liquid-gas chromatography coupling used for the determination of MOSH and MOAH in foodstuffs. The response ratios of alkanes comprised between C10 and C50 were measured and were comprised between 0.9 and 1.1, with a maximum coefficient of variation of 4% (n = 5). Intermediate precision was evaluated for the fat/oil category during a period of 48 days obtaining a value of 10%. Qualitative and quantitative analysis of both MOSH and MOAH were performed in a single run and in a fully-automated manner. Seventeen different foods were analyzed in order to cover the categories reported in the EU guide. Saturated hydrocarbon contamination was detected only in a few samples (in the range 1-153 ppm); MOAH contamination was found only in one sample (sunflower oil: 15 ppm).
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Affiliation(s)
- Mariosimone Zoccali
- Department of Mathematical and Computer Science, Physical Sciences and Earth Sciences, University of Messina, Messina, Italy.
| | - Tania M G Salerno
- BeSep s.r.l., c/o Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Peter Q Tranchida
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
| | - Luigi Mondello
- BeSep s.r.l., c/o Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy; Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy; Chromaleont s.r.l., c/o Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy; Unit of Food Science and Nutrition, Department of Medicine, University Campus Bio-Medico of Rome, Rome, Italy.
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Zoccali M, Tranchida PQ, Mondello L. A lab-developed interface for liquid-gas chromatography coupling based on the use of a modified programmed-temperature-vaporizing injector. J Chromatogr A 2020; 1622:461096. [DOI: 10.1016/j.chroma.2020.461096] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 03/25/2020] [Accepted: 03/31/2020] [Indexed: 11/27/2022]
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Martínez RM, Barba C, Robredo S, Herraiz M. Improving enantiomeric resolutions by avoiding peak distortion effects in on-line coupled liquid chromatography to gas chromatography. Chirality 2019; 31:879-891. [PMID: 31429160 DOI: 10.1002/chir.23121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 07/12/2019] [Accepted: 07/22/2019] [Indexed: 11/05/2022]
Abstract
In this work, we study the effect of different variables affecting elution profile distortion on the enantiomeric resolution eventually achievable when working with on-line coupled liquid chromatography to gas chromatography (LC-GC). Specifically, the proposed configuration combines achiral reversed-phase liquid chromatography (RPLC) and chiral gas chromatography (enantio-GC), with heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin as enantioselective stationary phase to analyse target fractions transferred (from LC to GC) via the through oven transfer adsorption desorption (TOTAD) interface. The high degree of orthogonality resulting from the combination of two chromatographic columns having very different separation mechanisms (and also requiring mobile phases in distinct physical states), as well as integration of the sample preparation step in the first dimension of the system, significantly contributed to exploit the performance of the proposed two-dimensional approach. Occasional adverse effects, which may result in severe peak distortions during LC-GC analysis and could be explained by flow instabilities due to viscous fingering, are circumvented by using the outstanding capacity of the TOTAD interface for achieving effective elimination of the eluent arriving from the LC preseparation.
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Affiliation(s)
- Rosa M Martínez
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Carmen Barba
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Sergio Robredo
- Laboratorio Arbitral Agroalimentario (LAA), Ministerio de Agricultura, Alimentación y Medio Ambiente, Madrid, Spain
| | - Marta Herraiz
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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Aragón Á, Toledano RM, Vázquez A, Villén J, Cortés JM. Analysis of polycyclic aromatic hydrocarbons in aqueous samples by large volume injection gas chromatography–mass spectrometry using the through oven transfer adsorption desorption interface. Talanta 2015; 139:1-5. [DOI: 10.1016/j.talanta.2015.02.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 02/10/2015] [Accepted: 02/17/2015] [Indexed: 11/16/2022]
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Aragón Á, Toledano RM, Gea S, Cortés JM, Vázquez AM, Villén J. Large volume injection in gas chromatography using the through oven transfer adsorption desorption interface operating under vacuum. Talanta 2014; 123:39-44. [PMID: 24725862 DOI: 10.1016/j.talanta.2014.01.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/24/2014] [Accepted: 01/29/2014] [Indexed: 11/29/2022]
Abstract
The present work describes a modification of the Through Oven Transfer Adsorption Desorption (TOTAD) interface, consisting of coupling a vacuum system to reduce the consumption of the helium needed to totally remove the eluent for large volume injection (LVI) in gas chromatography (GC). Two different retention materials in the liner of the TOTAD interface were evaluated: Tenax TA, which was seen to be unsuitable for working under vacuum conditions, and polydimethylsiloxane (PDMS), which provided satisfactory repeatability as well as a good sensitivity. No variability was observed in the retention times in either case. Solutions containing organophosphorous pesticides in two different solvents, a polar (methanol/water) and a non-polar (hexane) solvent, were used to evaluate the modification. The vacuum system coupled to the TOTAD interface allowed up to 90% helium to be saved without affecting the performance.
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Affiliation(s)
- Álvaro Aragón
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
| | - Rosa M Toledano
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
| | - Sara Gea
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
| | - José M Cortés
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain.
| | - Ana M Vázquez
- Facultad de Educación, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
| | - Jesús Villén
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
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Martínez RM, Herraiz M, Santa-María G, Barba C. On-line coupled reversed phase liquid chromatography and gas chromatography: a new sealing design for the TOTAD interface. Talanta 2014; 120:23-9. [PMID: 24468337 DOI: 10.1016/j.talanta.2013.11.083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/22/2013] [Accepted: 11/28/2013] [Indexed: 11/29/2022]
Abstract
Total elimination of the eluent resulting from the pre-separation step is the critical point when coupling LC to GC. As a helium flow is applied during transfer to eliminate the solvent, the interface used for linking the two chromatographic systems must be properly sealed to prevent gas leaks and to achieve an effective evaporation of the eluent. The aim of this work was to improve the performance of the Through Oven Transfer Adsorption Desorption (TOTAD) interface to remove the eluent coming from LC by modifying the way in which the injector sealing system is held in place. As with the original design, the new approach makes it possible to transfer high volumes at a high rate, but the proposed modification also simplifies the experimental work because the displacement risk of the sealing system is reduced. Analyses of an ester mixture by RPLC-GC were performed to confirm the applicability of the system modification. In this work, volumes of up to 5 ml, at flow rates as high as 2 ml/min, were transferred from LC to GC with almost complete solvent removal even when working in reversed phase mode in the LC step.
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Affiliation(s)
- Rosa María Martínez
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), c/Juan de la Cierva 3, 28006 Madrid, Spain.
| | - Marta Herraiz
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), c/Juan de la Cierva 3, 28006 Madrid, Spain
| | - Guillermo Santa-María
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), c/Juan de la Cierva 3, 28006 Madrid, Spain
| | - Carmen Barba
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN), Consejo Superior de Investigaciones Científicas (CSIC), c/Juan de la Cierva 3, 28006 Madrid, Spain
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Barba C, Santa-María G, Herraiz M, Martínez RM. Direct enantiomeric analysis of Mentha essential oils. Food Chem 2013; 141:542-7. [DOI: 10.1016/j.foodchem.2013.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 02/19/2013] [Accepted: 03/02/2013] [Indexed: 01/11/2023]
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9
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Programmed temperature vaporizing injector to filter off disturbing high boiling and involatile material for on-line high performance liquid chromatography gas chromatography with on-column transfer. J Chromatogr A 2013; 1281:106-14. [DOI: 10.1016/j.chroma.2013.01.070] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 11/17/2022]
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10
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Purcaro G, Moret S, Conte L. Sample pre-fractionation of environmental and food samples using LC-GC multidimensional techniques. Trends Analyt Chem 2013. [DOI: 10.1016/j.trac.2012.10.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Toledano RM, Martínez RM, Barba C, Cortés JM, Calvo MM, Santa-María G, Herraiz M. A quick method for identifying radiolytic hydrocarbons in low-fat-containing food. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2013; 93:479-484. [PMID: 22806617 DOI: 10.1002/jsfa.5787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 04/13/2012] [Accepted: 06/01/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND As radiation-induced alterations of the lipid fraction of foods are related to their initial fat content, concentrations of fat degradation products used as irradiation markers are expected to be lower when irradiating low-fat-containing foods. Thus the sensitivity required when applying analytical methods for identifying irradiation markers in foods eventually depends on their respective amounts of fat. The aim of this study was to perform the qualitative analysis of characteristic hydrocarbons resulting from irradiation of samples with a fat content as low as 25 g kg(-1). RESULTS A rapid extraction using a small amount of ethyl acetate was the unique sample pretreatment required to accomplish the analysis of radiolytic markers by using on-line coupling of reverse phase liquid chromatography and gas chromatography with mass spectrometry detection (RPLC/GC/MS). Efficient elimination of the large volumes (up to 2170 µL) directly transferred from LC to GC was achieved by optimising the operation mode of the through-oven transfer adsorption/desorption system used as interface. CONCLUSION The reported procedure allowed confirmation, in less than 65 min, of the occurrence of up to five irradiation markers, namely n-pentadecane, 1-hexadecene, 1,7-hexadecadiene, n-heptadecane and 8-heptadecene, in cooked ham irradiated at doses as low as 2 kGy.
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Affiliation(s)
- Rosa M Toledano
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha (UCLM), Campus Universitario s/n, Albacete, Spain
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Toledano RM, Cortés JM, Rubio-Moraga Á, Villén J, Vázquez A. Analysis of free and esterified sterols in edible oils by online reversed phase liquid chromatography–gas chromatography (RPLC–GC) using the through oven transfer adsorption desorption (TOTAD) interface. Food Chem 2012; 135:610-5. [DOI: 10.1016/j.foodchem.2012.04.097] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 12/19/2011] [Accepted: 04/15/2012] [Indexed: 11/16/2022]
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13
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Toledano RM, Díaz-Plaza EM, Cortés JM, Blázquez I, Vázquez A, Villén J, Muñoz-Guerra J. Analysis of steroids in human urine by on line liquid chromatography–gas chromatography–mass spectrometry using the Through Oven Transfer Adsorption Desorption interface and a fraction collector. Anal Chim Acta 2012; 741:78-85. [DOI: 10.1016/j.aca.2012.06.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Revised: 06/27/2012] [Accepted: 06/30/2012] [Indexed: 10/28/2022]
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14
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Hyphenated liquid chromatography–gas chromatography technique: Recent evolution and applications. J Chromatogr A 2012; 1255:100-11. [DOI: 10.1016/j.chroma.2012.02.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Revised: 02/06/2012] [Accepted: 02/07/2012] [Indexed: 11/21/2022]
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Biedermann M, Grob K. On-line coupled high performance liquid chromatography–gas chromatography for the analysis of contamination by mineral oil. Part 1: Method of analysis. J Chromatogr A 2012; 1255:56-75. [DOI: 10.1016/j.chroma.2012.05.095] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 05/26/2012] [Accepted: 05/30/2012] [Indexed: 10/28/2022]
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16
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Toledano RM, Cortés JM, Andini JC, Vázquez A, Villén J. On-line derivatization with on-line coupled normal phase liquid chromatography–gas chromatography using the through oven transfer adsorption desorption interface: Application to the analysis of total sterols in edible oils. J Chromatogr A 2012; 1256:191-6. [DOI: 10.1016/j.chroma.2012.07.057] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 07/12/2012] [Accepted: 07/16/2012] [Indexed: 10/28/2022]
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17
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Barba C, Martínez RM, Calvo MM, Santa-María G, Herraiz M. Chiral analysis by online coupling of reversed-phase liquid chromatography to gas chromatography and mass spectrometry. Chirality 2012; 24:420-6. [DOI: 10.1002/chir.22036] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 02/15/2012] [Indexed: 01/11/2023]
Affiliation(s)
- Carmen Barba
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN); Consejo Superior de Investigaciones Científicas (CSIC); c/ Juan de la Cierva 3; 28006; Madrid; Spain
| | - Rosa M. Martínez
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN); Consejo Superior de Investigaciones Científicas (CSIC); c/ Juan de la Cierva 3; 28006; Madrid; Spain
| | - Marta M. Calvo
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN); Consejo Superior de Investigaciones Científicas (CSIC); c/ Juan de la Cierva 3; 28006; Madrid; Spain
| | - Guillermo Santa-María
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN); Consejo Superior de Investigaciones Científicas (CSIC); c/ Juan de la Cierva 3; 28006; Madrid; Spain
| | - Marta Herraiz
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN); Consejo Superior de Investigaciones Científicas (CSIC); c/ Juan de la Cierva 3; 28006; Madrid; Spain
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Critical overview of selected contemporary sample preparation techniques. J Chromatogr A 2012; 1221:84-98. [DOI: 10.1016/j.chroma.2011.11.011] [Citation(s) in RCA: 208] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 10/26/2011] [Accepted: 11/06/2011] [Indexed: 11/18/2022]
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Pena-Abaurrea M, Ramos L. Miniaturization of Analytical Methods. CHALLENGES IN GREEN ANALYTICAL CHEMISTRY 2011. [DOI: 10.1039/9781849732963-00107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This chapter highlights miniaturization in sample preparation as a valuable alternative for green analytical chemistry. The current state of the art is discussed on the basis of examples selected from representative application areas, including biomedical, environmental and food analysis, and involving conventional instrumental techniques for final determination of the target compounds. The emphasis is on those techniques and approaches that have already demonstrated their practicality by the analysis of real-life samples, and in particular on those dealing with the accurate determination of minor organic components. The potential of recent developments in this field for sample treatment simplification and complete hyphenation of analytical processes are discussed and the most pressing remaining limitations evaluated.
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Affiliation(s)
- Miren Pena-Abaurrea
- Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry CSIC, Juan de la Cierva 3, 28006 Madrid Spain
| | - Lourdes Ramos
- Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry CSIC, Juan de la Cierva 3, 28006 Madrid Spain
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Aragón Á, Cortés JM, Toledano RM, Villén J, Vázquez A. Analysis of wax esters in edible oils by automated on-line coupling liquid chromatography–gas chromatography using the through oven transfer adsorption desorption (TOTAD) interface. J Chromatogr A 2011; 1218:4960-5. [DOI: 10.1016/j.chroma.2010.12.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 12/02/2010] [Accepted: 12/11/2010] [Indexed: 10/18/2022]
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Hamieh T. Determination of Lewis Acid Base Properties of Poly(α-n-alkyl) Methacrylates Adsorbed on Silica by Inverse GC. Chromatographia 2011. [DOI: 10.1007/s10337-011-1925-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Toledano RM, Cortés JM, Andini JC, Villén J, Vázquez A. Large volume injection of water in gas chromatography–mass spectrometry using the Through Oven Transfer Adsorption Desorption interface: Application to multiresidue analysis of pesticides. J Chromatogr A 2010; 1217:4738-42. [DOI: 10.1016/j.chroma.2010.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2010] [Revised: 04/29/2010] [Accepted: 05/04/2010] [Indexed: 10/19/2022]
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Development of a method based on on-line reversed phase liquid chromatography and gas chromatography coupled by means of an adsorption–desorption interface for the analysis of selected chiral volatile compounds in methyl jasmonate treated strawberries. J Chromatogr A 2010; 1217:1083-8. [DOI: 10.1016/j.chroma.2009.10.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 10/09/2009] [Accepted: 10/12/2009] [Indexed: 11/18/2022]
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Use of absorbent materials in on-line coupled reversed-phase liquid chromatography–gas chromatography via the through oven transfer adsorption desorption interface. J Chromatogr A 2008; 1211:99-103. [DOI: 10.1016/j.chroma.2008.09.075] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2008] [Revised: 09/21/2008] [Accepted: 09/23/2008] [Indexed: 11/23/2022]
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25
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Hoh E, Mastovska K. Large volume injection techniques in capillary gas chromatography. J Chromatogr A 2008; 1186:2-15. [DOI: 10.1016/j.chroma.2007.12.001] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2007] [Revised: 11/28/2007] [Accepted: 12/03/2007] [Indexed: 11/29/2022]
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26
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Flores G, Blanch GP, Ruiz del Castillo ML. Through oven transfer adsorption-desorption interface for the analysis of methyl jasmonate in aromatic samples by on-line RPLC-GC. J Sep Sci 2008; 31:1207-14. [DOI: 10.1002/jssc.200700614] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Kerkdijk H, Mol HGJ, van der Nagel B. Volume Overload Cleanup: An Approach for On-Line SPE-GC, GPC-GC, and GPC-SPE-GC. Anal Chem 2007; 79:7975-83. [PMID: 17896824 DOI: 10.1021/ac0701536] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new concept for cleanup, based on volume overloading of the cleanup column, has been developed for on-line coupling of gel permeation chromatography (GPC), solid-phase extraction (SPE), or both, to gas chromatography (GC). The principle is outlined and the applicability demonstrated by the determination of pesticide residues in food matrixes using integrated and automated cleanup-GC-MS. Compared to conventional approaches for on-line cleanup-GC, the new technique involves introduction of much smaller volumes (e.g., 2-20 microL) into the GC without sacrificing method LODs. The much smaller injection volumes involved greatly simplify on-line coupling, improve robustness, and increase attractiveness for implementation in routine laboratories.
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Affiliation(s)
- Henk Kerkdijk
- Department of Analytical Research, TNO Quality of Life, Utrechtseweg 48, 3704 HE Zeist, The Netherlands.
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Flores G, Ruiz del Castillo ML, Herraiz M. Enantiomeric analysis of β-pinene and limonene by direct coupling of reversed phase liquid chromatography and gas chromatography using absorbents as packing materials. J Sep Sci 2007; 30:2780-5. [PMID: 17823897 DOI: 10.1002/jssc.200700248] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A method based on the use of absorbents as packing materials inside the interface of the online coupling between RPLC and GC is proposed for the enantiomeric analysis of beta-pinene and limonene in essential oils. For that purpose, a comparison of the RSD, detection limit and recovery provided by two absorbents and one adsorbent is included in this study. The results found in this work proved the validity of absorbents as packing materials in online RPLC-GC to determine minor compounds in complex matrices. In particular, PDMS seemed to be specially useful to analyse nonpolar compounds, such as beta-pinene and limonene, since it provided higher sensitivity for this kind of compounds. The developed method was applied to the evaluation of the natural and non-natural character of commercial essential oils by means of the determination of the enantiomeric composition of beta-pinene and limonene.
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Affiliation(s)
- Gema Flores
- Instituto de Fermentaciones Industriales, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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Cortés JM, Sanchez R, Villén J, Vazquez A. Analysis of unsaponifiable compounds of edible oils by automated on-line coupling reversed-phase liquid chromatography-gas chromatography using the through oven transfer adsorption desorption interface. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:6963-8. [PMID: 16968049 DOI: 10.1021/jf060956e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
An automated method for analysis of unsaponifiable compounds in edible oils is presented. The method involves the on-line coupling of reversed-phase liquid chromatography and gas chromatography (LC-GC) using the through oven transfer adsorption desorption (TOTAD) interface. The oil is injected directly with no sample pretreatment step other than filtration. It may also be considered to dilute the oil sample. In the LC step, a short C4 column using a methanol/water eluent separates analytes from the other components of the oils, which are made up of mainly triglycerides. A LC fraction of up to 1.6 mL containing the analytes is transferred to GC at a flow rate of 0.1-2 mL/min. The TOTAD interface allows solvent venting and the introduction of the analytes into the GC column. The proposed fully automated method allows the analysis of different groups of compounds (free sterols, tocopherols, squalene, and erythrodiol and uvaol) in one chromatographic run or the analysis of these compounds in different groups. Sensitivity is more than necessary, and repeatability is good, the CV ranging from 3 to 12% for the full analysis.
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Affiliation(s)
- Jose Manuel Cortés
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
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30
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Ramos L, Ramos JJ, Brinkman UAT. Miniaturization in sample treatment for environmental analysis. Anal Bioanal Chem 2004; 381:119-40. [PMID: 15602622 DOI: 10.1007/s00216-004-2906-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Revised: 10/17/2004] [Accepted: 10/18/2004] [Indexed: 10/26/2022]
Abstract
The increasing demand for faster, more cost-effective and environmentally friendly analytical methods is a major incentive to improve the classical procedures used for sample treatment in environmental analysis. In most classical procedures, the use of rapid and powerful instrumental techniques for the final separation and detection of the analytes contrasts with the time-consuming and usually manual methods used for sample preparation, which slows down the total analytical process. The efforts made in this field in the past ten years have led to the adaptation of existing methods and the development of new techniques to save time and chemicals, and improve overall performance. One route has been to develop at-line or on-line and, frequently, automated systems. In these approaches, miniaturization has been a key factor in designing integrated analytical systems to provide higher sample throughput and/or unattended operation. Selected examples of novel developments in the field of miniaturized sample preparation for environmental analysis are used to evaluate the merits of the various techniques on the basis of published data on real-life analyses of trace-level organic pollutants. Perspectives and trends are briefly discussed.
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Affiliation(s)
- L Ramos
- Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, CSIC, Juan de la Cierva 3, 28006 Madrid, Spain.
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Sanchez R, Vazquez A, Andini JC, Villén J. Automated multiresidue analysis of pesticides in olive oil by on-line reversed-phase liquid chromatography–gas chromatography using the through oven transfer adsorption–desorption interface. J Chromatogr A 2004; 1029:167-72. [PMID: 15032362 DOI: 10.1016/j.chroma.2003.12.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A multiresidue, automated and rapid method for the determination of pesticide residues in olive oil is presented. The method employs the through oven transfer adsorption-desorption interface for the on-line coupling of reversed-phase liquid chromatography and gas chromatography. In this fully automated system, olive oil is directly injected with no sample pre-treatment step other than filtration. Methanol-water is used as eluent in the liquid chromatography pre-separation step. The selected liquid chromatography fraction containing the pesticides is automatically transferred to the gas chromatography. The liquid chromatography column flow during elution is different from the flow during the transfer. Using a flame ionisation detector, pesticide detection limits varied from 0.1 to 0.3 mg/l.
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Affiliation(s)
- R Sanchez
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n, 02071 Albacete, Spain
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32
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Sanchez R, Vázquez A, Riquelme D, Villén J. Direct analysis of pesticide residues in olive oil by on-line reversed phase liquid chromatography-gas chromatography using an automated through oven transfer adsorption desorption (TOTAD) interface. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2003; 51:6098-6102. [PMID: 14518929 DOI: 10.1021/jf030182r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A fully automated on-line reversed phase liquid chromatography-gas chromatography system is described. The system uses a prototype of the automated through oven transfer adsorption desorption interface. The system is demonstrated by presenting a new rapid method for the determination of pesticide residue in olive oil, which is injected directly with no sample pretreatment step other than filtration. Methanol:water is used as the eluent in the LC preseparation step, while the LC fraction containing the pesticide is automatically transferred to the gas chromatograph. Detection limits of pesticides varied from 0.18 to 0.44 mg/L when a flame ionization detector was used. As an example, relative standard deviation and linear calibration are presented for terbutryne.
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Affiliation(s)
- Raquel Sanchez
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Campus Universitario s/n. 02071 Albacete, Spain
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Abstract
On-line coupled liquid chromatography-gas chromatography (LC-GC) is a powerful technique that combines the best features of LC and GC and is ideal for the analysis of complex samples. This review describes the unique features of on-line coupled LC-GC. The different interfaces and evaporation techniques are presented, along with their advantages and disadvantages. Guidelines are given for selecting a suitable LC-GC technique and representative applications are noted.
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Affiliation(s)
- Tuulia Hyötyläinen
- Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland.
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Perez M, Alario J, Vazquez A, Villén J. Pesticide residue analysis by off-line SPE and on-line reversed-phase LC-GC using the through-oven-transfer adsorption/desorption interface. Anal Chem 2000; 72:846-52. [PMID: 10701272 DOI: 10.1021/ac990438l] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new method to determine pesticide residue in water is presented. The described method includes using off-line solid-phase extraction (SPE) and on-line reversed-phase liquid chromatography-gas chromatography (RPLC-GC). An interface, based on a modified programmed temperature vaporizer (PTV) injector, packed with a suitable trapping material, is used for on-line RPLC-GC. The changes made in the PTV injector affect the pneumatic system, sample introduction, and solvent elimination. The new interface is easily capable of automation. Methanol/wate (70/30) is used as the eluent in the LC preseparation step. The LC column flow during elution is different from the flow during the transfer step. The transferred volumes range from 500 to 1400 microL (volume of the fractions of interest). Solvent elimination is almost 100% before the sample reaches the GC column. The described system does not show any variation of the peak retention times. The detection limit for real samples ranges from 0.04 to 1.5 ng/L, using NP detection.
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Affiliation(s)
- M Perez
- Escuela Técnica Superior de Ingenieros Agrónomos, Universidad de Castilla-La Mancha, Albacete, Spain
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