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Torabizadeh M, Tabar-Heydar K, Ahmadi SH. Online Solid-Phase Extraction of Prometon and Prometryne Using MIL-101(Cr) as Sorbent before Gas Chromatographic Analysis: A Computational and Experimental Study and Comparison between Splitless and PTV Inlets. J Chromatogr Sci 2021; 60:887-896. [PMID: 34969083 DOI: 10.1093/chromsci/bmab140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Indexed: 11/14/2022]
Abstract
In this study, prometryne and prometon were extracted and preconcentrated from aqueous media using an online solid-phase extraction-thermal desorption method coupled with gas chromatography-flame ionization detector (GC-FID), equipped with two different inlets: split and programmable temperature vaporizer (PTV). For this purpose, the applicability of Tenax and a metal-organic framework were investigated as solid-phase sorbents. Several effective parameters on the extraction efficiency, such as the amount of sorbent, sample volume, sample pH and thermal desorption procedure were optimized. The analytical performance of the proposed methods showed an excellent linear dynamic range for prometon and prometryne (0.25-100 μg/L) and relative standard deviation less than 4.01%. Moreover, the detection limits below 0.20 and 0.35 μg/L were determined for prometon and prometryne, respectively. Additionally, molecular docking was applied to clarify the adsorption nature and binding energy of MIL-101(Cr) toward the studied analytes, which indicated an appropriate correlation between computational and experimental results. Finally, the proposed method was developed and validated for prometon and prometryne and successfully applied for their extraction from agricultural water, spiked with prometon and prometryne through its direct introduction into the GC inlet.
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Affiliation(s)
- Mahsa Torabizadeh
- Faculty of Clean Technologies, Chemistry and Chemical Engineering Research Center of Iran, Pajohesh Blvd, 17th Km of Tehran-Karaj Highway, Tehran, Iran
| | - Kourosh Tabar-Heydar
- Faculty of Clean Technologies, Chemistry and Chemical Engineering Research Center of Iran, Pajohesh Blvd, 17th Km of Tehran-Karaj Highway, Tehran, Iran
| | - Seyyed Hamid Ahmadi
- Faculty of Clean Technologies, Chemistry and Chemical Engineering Research Center of Iran, Pajohesh Blvd, 17th Km of Tehran-Karaj Highway, Tehran, Iran
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2
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Dugheri S, Mucci N, Bonari A, Marrubini G, Cappelli G, Ubiali D, Campagna M, Montalti M, Arcangeli G. Solid phase microextraction techniques used for gas chromatography: a review. ACTA CHROMATOGR 2020. [DOI: 10.1556/1326.2018.00579] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In the last decade, the development and adoption of greener and sustainable microextraction techniques have been proved to be an effective alternative to classical sample preparation procedures. In this review, 10 commercially available solid-phase microextraction systems are presented, with special attention to the appraisal of their analytical, bioanalytical, and environmental engineering. This review provides an overview of the challenges and achievements in the application of fully automated miniaturized sample preparation methods in analytical laboratories. Both theoretical and practical aspects of these environment-friendly preparation approaches are discussed. The application of chemometrics in method development is also discussed. We are convinced that green analytical chemistry will be really useful in the years ahead. The application of cheap, fast, automated, “clever”, and environmentally safe procedures to environmental, clinical, and food analysis will improve significantly the quality of the analytical data.
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Affiliation(s)
- Stefano Dugheri
- 1 Industrial Hygiene and Toxicology Laboratory, Careggi University Hospital, Florence, Italy
| | - Nicola Mucci
- 2 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Alessandro Bonari
- 2 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | | | - Giovanni Cappelli
- 2 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Daniela Ubiali
- 3 Department of Drug Sciences, University of Pavia, Pavia, Italy
| | - Marcello Campagna
- 4 Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Manfredi Montalti
- 2 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Giulio Arcangeli
- 2 Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
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3
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Simultaneous determination of drugs and pesticides in postmortem blood using dispersive solid-phase extraction and large volume injection-programmed temperature vaporization-gas chromatography–mass spectrometry. Forensic Sci Int 2018; 290:318-326. [DOI: 10.1016/j.forsciint.2018.07.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/23/2018] [Accepted: 07/27/2018] [Indexed: 12/15/2022]
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4
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Zhang L, Zhong Y, Liu X, Bao Y, Zhao Y, Wu Y, Cai Z, Li J. Determination of polychlorinated dibenzo-p
-dioxins and polychlorinated dibenzofurans, and dioxin-like polychlorinated biphenyls in human serum using programmable-temperature vaporization gas chromatography with high-resolution mass spectrometry. J Sep Sci 2017; 40:3453-3461. [DOI: 10.1002/jssc.201700465] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 06/07/2017] [Accepted: 06/23/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Lei Zhang
- The Key Laboratory of Food Safety Risk Assessment; Ministry of Health (CFSA) and China National Center for Food Safety Risk Assessment; Beijing China
| | - Yuxin Zhong
- Department of Pancreatogastric Surgery, National Cancer Center/Cancer Hospital; Chinese Academy of Medical Science and Peking Union Medical College; Beijing China
| | - Xin Liu
- The Key Laboratory of Food Safety Risk Assessment; Ministry of Health (CFSA) and China National Center for Food Safety Risk Assessment; Beijing China
- State Key Lab of Food Science and Technology; Nanchang University; Nanchang China
| | - Yan Bao
- The Key Laboratory of Food Safety Risk Assessment; Ministry of Health (CFSA) and China National Center for Food Safety Risk Assessment; Beijing China
| | - Yunfeng Zhao
- The Key Laboratory of Food Safety Risk Assessment; Ministry of Health (CFSA) and China National Center for Food Safety Risk Assessment; Beijing China
| | - Yongning Wu
- The Key Laboratory of Food Safety Risk Assessment; Ministry of Health (CFSA) and China National Center for Food Safety Risk Assessment; Beijing China
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis; Department of Chemistry; Hong Kong Baptist University; Hong Kong China
| | - Jingguang Li
- The Key Laboratory of Food Safety Risk Assessment; Ministry of Health (CFSA) and China National Center for Food Safety Risk Assessment; Beijing China
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5
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6
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Alonso Sobrado L, Robledo Fernández M, Cueto Díaz S, Ruiz Encinar J, García Alonso JI. Modification of a commercial gas chromatography isotope ratio mass spectrometer for on-line carbon isotope dilution: Evaluation of its analytical characteristics for the quantification of organic compounds. J Chromatogr A 2015; 1419:99-108. [DOI: 10.1016/j.chroma.2015.09.071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 09/16/2015] [Accepted: 09/21/2015] [Indexed: 10/23/2022]
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Buczyńska AJ, Geypens B, Van Grieken R, De Wael K. Large-volume injection combined with gas chromatography/isotope ratio mass spectrometry for the analysis of polycyclic aromatic hydrocarbons. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2014; 28:200-208. [PMID: 24338968 DOI: 10.1002/rcm.6769] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 10/01/2013] [Accepted: 10/18/2013] [Indexed: 06/03/2023]
Abstract
RATIONALE Compound-specific stable isotope analyses of carbon require relatively large amounts of sample for reliable analyses. Commonly applied injections of 1 μL may thus be insufficient for samples with low concentrations of pollutants (e.g. air particulate matter) or when the amount of a sample is limited. METHODS A Large-Volume Injection (LVI) method for carbon stable isotope ratio analysis of Polycyclic Aromatic Hydrocarbons (PAHs) was optimized in this study. Gas chromatography/combustion/isotope ratio mass spectrometry (GCCIRMS) and ion trap mass spectrometry (ITMS) were used for the determination of stable carbon isotope ratios and quantification of compounds, respectively. RESULTS The optimized method resulted in very good reproducibility, even for the most volatile PAH, naphthalene, when a small amount of higher boiling co-solvent was used. No significant fractionation of isotope ratios could be seen and the recoveries of analytes were similar to or better than that of a splitless cold injection. CONCLUSIONS Injection of 100 μL, instead of the commonly used 1 μL, increases the detection limit for PAHs significantly and/or simplifies the sample preparation step. Using our optimized method, stable carbon isotope ratios can be reliably measured in samples with concentrations of PAHs down to 0.05-0.1 ng μL(-1).
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Affiliation(s)
- Anna J Buczyńska
- Joint Research Centre - European Commission, Institute for Reference Materials and Measurements (IRMM), Retiesewg 111, B-2440, Geel, Belgium
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8
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Evaluation of a new column backflushing set-up in the gas chromatographic–tandem mass spectrometric analysis of pesticide residues in dietary supplements. J Chromatogr A 2012; 1265:155-64. [DOI: 10.1016/j.chroma.2012.09.094] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 09/26/2012] [Accepted: 09/27/2012] [Indexed: 11/22/2022]
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9
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Rahman MM, Choi JH, Abd El-Aty A, Abid MD, Park JH, Na TW, Kim YD, Shim JH. Pepper leaf matrix as a promising analyte protectant prior to the analysis of thermolabile terbufos and its metabolites in pepper using GC–FPD. Food Chem 2012; 133:604-10. [DOI: 10.1016/j.foodchem.2012.01.074] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 01/18/2012] [Accepted: 01/23/2012] [Indexed: 11/16/2022]
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Przybylski C, Segard C. Method for routine screening of pesticides and metabolites in meat based baby-food using extraction and gas chromatography-mass spectrometry. J Sep Sci 2009; 32:1858-67. [DOI: 10.1002/jssc.200900016] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Evaluation of some parameters affecting troublesome pesticide analysis in gas chromatography–ion-trap mass spectrometry. J Chromatogr A 2008; 1201:78-90. [DOI: 10.1016/j.chroma.2008.05.081] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 05/22/2008] [Accepted: 05/27/2008] [Indexed: 11/20/2022]
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12
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Optimisation of programmable temperature vaporizer-based large volume injection for determination of pesticide residues in fruits and vegetables using gas chromatography–mass spectrometry. J Chromatogr A 2008; 1190:316-26. [DOI: 10.1016/j.chroma.2008.03.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2007] [Revised: 02/29/2008] [Accepted: 03/04/2008] [Indexed: 11/19/2022]
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13
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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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14
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Cajka T, Hajslova J, Lacina O, Mastovska K, Lehotay SJ. Rapid analysis of multiple pesticide residues in fruit-based baby food using programmed temperature vaporiser injection–low-pressure gas chromatography–high-resolution time-of-flight mass spectrometry. J Chromatogr A 2008; 1186:281-94. [DOI: 10.1016/j.chroma.2007.12.009] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 11/28/2007] [Accepted: 12/03/2007] [Indexed: 11/26/2022]
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15
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Mastovska K. Chapter 6 Recent Developments in Chromatographic Techniques. FOOD CONTAMINANTS AND RESIDUE ANALYSIS 2008. [DOI: 10.1016/s0166-526x(08)00006-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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16
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Mol HGJ, Rooseboom A, van Dam R, Roding M, Arondeus K, Sunarto S. Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce. Anal Bioanal Chem 2007; 389:1715-54. [PMID: 17563885 PMCID: PMC2117333 DOI: 10.1007/s00216-007-1357-1] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 05/04/2007] [Accepted: 05/08/2007] [Indexed: 11/29/2022]
Abstract
The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary-secondary amine and graphitized carbon black) and large-volume (20 muL) injection. The same extract, before clean-up and after a change of solvent, was also analyzed by liquid chromatography with tandem mass spectrometry (LC-MS-MS). All aspects related to sample preparation were re-assessed with regard to ease and speed of the analysis. The principle of the extraction procedure (solvent, salt) was not changed, to avoid the possibility invalidating data acquired over past decades. The modifications were made with techniques currently commonly applied in routine laboratories, GC-MS and LC-MS-MS, in mind. The modified method enables processing (from homogenization until final extracts for both GC and LC) of 30 samples per eight hours per person. Limits of quantification (LOQs) of 0.01 mg kg(-1) were achieved with both GC-MS (full-scan acquisition, 10 mg matrix equivalent injected) and LC-MS-MS (2 mg injected) for most of the pesticides. Validation data for 341 pesticides and degradation products are presented. A compilation of analytical quality-control data for pesticides routinely analyzed by GC-MS (135 compounds) and LC-MS-MS (136 compounds) in over 100 different matrices, obtained over a period of 15 months, are also presented and discussed. At the 0.05 mg kg(-1) level acceptable recoveries were obtained for 93% (GC-MS) and 92% (LC-MS-MS) of pesticide-matrix combinations.
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Affiliation(s)
- Hans G J Mol
- Rikilt Institute of Food Safety, Pesticides and Contaminants, P.O. Box 230, 6700 AE, Wageningen, The Netherlands.
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17
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Mastovská K, Lehotay SJ, Anastassiades M. Combination of analyte protectants to overcome matrix effects in routine GC analysis of pesticide residues in food matrixes. Anal Chem 2007; 77:8129-37. [PMID: 16351165 DOI: 10.1021/ac0515576] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Analyte protectants were previously defined as compounds that strongly interact with active sites in the gas chromatographic (GC) system, thus decreasing degradation, adsorption, or both of coinjected analytes. In this study, we evaluated various combinations of promising analyte protectants for the volatility range of GC-amenable pesticides using GC/quadrupole mass spectrometry (MS) and 1-microL hot splitless injection for sample introduction. A mixture of ethylglycerol, gulonolactone, and sorbitol (at 10, 1, and 1 mg/mL, respectively, in the injected samples) was found to be the most effective in minimizing losses of susceptible analytes and significantly improving their peak shapes (due to reduction of peak tailing). When added to final sample extracts and matrix-free calibration standards alike, these analyte protectants induced a similar response enhancement in both instances, resulting in effective equalization of the matrix-induced response enhancement effect even after a large number of fruit and vegetable extract injections. As compared to matrix-matched standardization, the analyte protectant approach offers a more convenient solution to the problems associated with calibration in routine GC/MS analysis of pesticide residues and possibly other susceptible analyte types in diverse samples. Moreover, the use of analyte protectants also substantially reduced another adverse matrix-related effect caused by gradual build-up of nonvolatile matrix components in the GC system, thus improving ruggedness and, consequently, reducing need for frequent maintenance.
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Affiliation(s)
- Katerina Mastovská
- Agricultural Research Service, Eastern Regional Research Center, U.S. Department of Agriculture, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA
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Díez C, Traag WA, Zommer P, Marinero P, Atienza J. Comparison of an acetonitrile extraction/partitioning and “dispersive solid-phase extraction” method with classical multi-residue methods for the extraction of herbicide residues in barley samples. J Chromatogr A 2006; 1131:11-23. [PMID: 16904120 DOI: 10.1016/j.chroma.2006.07.046] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 07/07/2006] [Accepted: 07/10/2006] [Indexed: 10/24/2022]
Abstract
An acetonitrile/partitioning extraction and "dispersive solid-phase extraction (SPE)" method that provides high quality results with a minimum number of steps and a low solvent and glassware consumption was published in 2003. This method, suitable for the analysis of multiple classes of pesticide residues in foods, has been given an acronymic name, QuEChERS, that reflects its major advantages (quick, easy, cheap, effective, rugged, safe). In this work, QuEChERS method, which was originally created for vegetable samples with a high amount of water, was modified to optimise the extraction of a wide range of herbicides in barley. Then, it was compared with known conventional multi-residue extraction procedures such as the Luke method, which was simplified and shortened by eliminating the Florisil clean-up (mini Luke) and the ethyl acetate extraction, which involves a subsequent clean-up by gel permeation chromatography (GPC) and which is the official extraction method used by some of European authorities. Finally, a simple acetone extraction was carried out to check the differences with the other three methods. Extracts were analysed by gas chromatography-time-of-flight mass spectrometry (GC-TOF/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Mini Luke was significantly more effective for the extraction of non-polar and medium-polar compounds, but the best recoveries for polar compounds were achieved by QuEChERS and ethyl acetate methods. QuEChERS was the only method that provided an overall recovery value of 60-70% for non-, medium- and polar compounds, with some exceptions due to co-eluted matrix interferences. Clean-up by dispersive SPE was effective and did not differ so much with ethyl acetate extracts considering that QuEChERS clean-up step is much easier and less time-consuming. As a conclusion, it resulted to be the most universal extraction method by providing a well-defined phase separation without dilution and achieving acceptable recoveries in average including the extraction of the always difficult acidic herbicides. However, recoveries were not as good as required for validation purposes suggesting that residues are prone to strong matrix interactions in dry samples as barley and further method adaptation incrementing solvent strength, extraction time or more acidic or basic conditions is needed in order to achieve a complete extraction.
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Affiliation(s)
- C Díez
- Laboratory of Physic-Chemical Analysis, ITACyL, Agrarian Technological Institute of Castilla y León, Ctra. Burgos, km.119, 47071 Valladolid, Spain.
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Patel K, Fussell RJ, Goodall DM, Keely BJ. Application of programmable temperature vaporisation injection with resistive heating-gas chromatography flame photometric detection for the determination of organophosphorus pesticides. J Sep Sci 2006; 29:90-5. [PMID: 16485713 DOI: 10.1002/jssc.200401872] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The combination of a programmable temperature vaporisation (PTV) injector with resistive heating GC (RH-GC), a form of fast GC, has been applied to the analysis of organophosphorus (OP) pesticides. The PTV injector was optimised in the 'at-once' solvent vent mode for the injection of ethyl acetate (10-40 microL) or ACN (10 microL). The short RH-GC column (5 m x 0.25 mm ID) with fast temperature ramps (up to 153 degrees C/ min) allowed the separation of a total of 20 OP pesticides in less than 6 min. Average recoveries between 67 and 119% were obtained for pesticides spiked at 0.01 mg/kg into apple and pear matrix. Extraction of orange juice with ACN provided higher recoveries (92-104%) for methamidophos, acephate and omethoate compared to ethyl acetate (62-73%). Results for analysis of OP pesticides in samples containing incurred residues were in good agreement with those obtained using GC-MS. The overall method was rapid, allowing 20 samples to be analysed in 4 h.
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Affiliation(s)
- Katan Patel
- Central Science Laboratory, Sand Hutton, York, UK
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Cai J, Gao Y, Zhu X, Su Q. Matrix solid phase dispersion-Soxhlet simultaneous extraction clean-up for determination of organochlorine pesticide residues in tobacco. Anal Bioanal Chem 2005; 383:869-74. [PMID: 16211380 DOI: 10.1007/s00216-005-0076-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Revised: 07/20/2005] [Accepted: 08/16/2005] [Indexed: 11/25/2022]
Abstract
A novel method combining matrix solid phase dispersion (MSPD) with Soxhlet simultaneous extraction clean-up (SSEC) was developed. Being a single-step extraction and clean-up procedure, it could be used instead of multistep solvent extraction and Florisol column clean-up. It not only reduces sample contamination during the procedure, but it also decreases the amount of organic solvent needed. The retention times of standards were used to qualitatively assess the method, and the external standard method was used to quantitatively assess it. Residues of organochlorine pesticides (OCP) in tobaccos were determined by gas chromatography-electron capture detection (GC-ECD), and their identities were confirmed by the standard addition method (SAM). The performance of the method was evaluated and validated: the detection limit was 0.01-0.02 microg g(-1), relative standard deviations were 5-26%, and recoveries were 72-99% at fortification levels of 0.10, 1.00 and 10.0 microg g(-1). The analytical characteristics of MSPD-SSEC compared very favorably with the results from the classical multistep solvent extraction and Florisol column clean-up method.
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Affiliation(s)
- Jibao Cai
- Department of Chemistry, University of Science & Technology of China, Hefei, 230026, PR China.
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21
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Leandro CC, Fussell RJ, Keely BJ. Determination of priority pesticides in baby foods by gas chromatography tandem quadrupole mass spectrometry. J Chromatogr A 2005; 1085:207-12. [PMID: 16106700 DOI: 10.1016/j.chroma.2005.06.054] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A gas chromatography-tandem quadrupole mass spectrometry (GC-MS/MS) method for the determination of twelve priority pesticides, and transformation products (e.g. metabolites) specified in the EU Baby Food Directive 2003/13/EC is described. Prior to GC-MS/MS analysis, co-extractives were removed from acetonitrile extracts using dispersive solid phase extraction with octadecyl (200 mg) and primary secondary amine (50 mg) sorbents. The clean up proved essential for the satisfactory long-term chromatographic performance during the analysis of a range of representative commercially pre-prepared baby food samples. Extracts spiked with pesticides at 1-8 microg kg(-1), yielded average recoveries in the range 60-113% with relative standard deviations less than 28%.
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Cajka T, Mastovská K, Lehotay SJ, Hajslová J. Use of automated direct sample introduction with analyte protectants in the GC–MS analysis of pesticide residues. J Sep Sci 2005; 28:1048-60. [PMID: 16013832 DOI: 10.1002/jssc.200500050] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Automated large-volume direct sample introduction, or difficult matrix introduction (DMI), was investigated in the determination of 44 pesticide residues possessing a wide range of physico-chemical properties (volatility, polarity, pK(a)) in fruit-based baby food by means of gas chromatography-mass spectrometry (GC-MS) with a quadrupole mass analyzer. DMI has advantages over traditional injection because large volumes (up to 30 microL) of potentially dirty sample extracts can be injected into the GC-MS, but nonvolatile matrix components that would normally contaminate the inlet are removed after every injection. The extra matrix and glass surfaces involved in DMI, however, make the system more prone to the matrix-induced chromatographic enhancement effect, which adversely affects quantification of several pesticides. To overcome this problem, matrix-matched calibration standards and/or the use of analyte protectants were applied in the DMI approach, and the analysis of extracts was also compared before and after undergoing clean-up by dispersive solid-phase extraction. For best quantification, clean-up was still needed, and the combination of matrix-matching with analyte protectants gave the most reproducible results. Depending on the application, however, the addition of analyte protectants (a mixture of 3-ethoxy-1,2-propanediol, L-gulonic acid 3-lactone, and D-sorbitol) to sample extracts and calibration standards in solvent (non-matrix matched), gave satisfactory quantification for most of the 44 pesticides tested. The lowest calibration levels for 34 of the 44 pesticides were < or = 10 ng/g, which meets the standard required by the European Union Baby Food Directive (2003/13/EC).
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Affiliation(s)
- Tomás Cajka
- Institute of Chemical Technology, Prague, Department of Food Chemistry and Analysis, Technická 3, 166 28 Prague 6, Czech Republic
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Bailey R. Injectors for capillary gas chromatography and their application to environmental analysis. ACTA ACUST UNITED AC 2005; 7:1054-8. [PMID: 16252052 DOI: 10.1039/b508334f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The application of different injectors in capillary gas chromatography (GC) analysis of semi-volatile organic contaminants in environmental samples prepared in organic solvents is reviewed. The injectors examined include a split/splitless injector in splitless mode (SS), cold on-column (COC), and programmable temperature vaporizer (PTV) and adaptations of these injector designs. Key issues when selecting an injector include properties of the analyte, such as potential for thermal degradation or discrimination of high boiling point compounds within the injector, and the ability of the GC systems to handle large volume injections (LVI) primarily to lower detection limits and allow direct coupling with sample preparation techniques such as at-line or on-line solid phase extraction (SPE). LVI also require consideration of matrix interference issues. This review examines only injector chamber modifications that are feasible with a standard GC configuration, however some modifications to the chromatographic system to extend the range of applicability of gas chromatography analysis for environmental samples are also noted.
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Affiliation(s)
- Renata Bailey
- Department of Chemistry & Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, USA
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Kirchner M, Matisová E, Dömötörová M, de Zeeuw J. Practical aspects of splitless injection of semivolatile compounds in fast gas chromatography. J Chromatogr A 2004; 1055:159-68. [PMID: 15560492 DOI: 10.1016/j.chroma.2004.07.058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Possibilities and practical aspects of implementation of splitless injection of larger volumes for fast GC purposes utilizing narrow-bore column, hydrogen as carrier gas, fast temperature programming under programmed flow conditions and commercial instrumentation were searched. As a model sample semivolatile compounds of a broad range of volatility and polarity (7 n-alkanes and 19 pesticides) were chosen. Peak shapes, peak broadening and peak areas and its repeatability were evaluated under various experimental set-ups (liner/injection technique combinations). Various factors, such as liner design, injection technique, retention gap length, compound volatility and polarity, the solvent used, initial oven temperature influenced compound focusation and/or maximal injection volume. Combination of analytical column (CP-Sil 13 CB 25 m long, 0.15 mm i.d., film thickness 0.4 microm) with normal-bore retention gap (1 m long, 0.32 mm i.d.) allowed maximal injection volume 8 microl for 4 mm i.d. liner used without any peak distortion when solvent recondensation in the retention gap was employed.
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Affiliation(s)
- Michal Kirchner
- Department of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37 Bratislava, Slovak Republic
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Anastassiades M, Mastovská K, Lehotay SJ. Evaluation of analyte protectants to improve gas chromatographic analysis of pesticides. J Chromatogr A 2003; 1015:163-84. [PMID: 14570329 DOI: 10.1016/s0021-9673(03)01208-1] [Citation(s) in RCA: 239] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A common problem in gas chromatography (GC) applications is the analyte losses and/or peak tailing due to undesired interactions with active sites in the inlet and column. Analytes that give poor peak shapes or degrade have higher detection limits, are more difficult to identify and integrate, and are more prone to interferences than stable analytes that give narrow peaks. For susceptible analytes, significant peak quality improvements are obtained when matrix components are present because they fill active sites, thus reducing analyte interactions. This phenomenon is called "matrix-induced chromatographic response enhancement." Several approaches have been proposed to minimize peak distortion phenomena and compensate for matrix-induced effects, which is especially important for accurate quantitation, but each approach has serious limitations for routine multi-pesticide analysis. In this study, we demonstrate the feasibility of using "analyte protectants" to provide a more convenient and effective solution to the problem than other approaches developed thus far. The protecting agents are added to extracts and matrix-free standards alike to provide the chromatographic enhancement effect even for the most susceptible analytes in a very dirty GC system. In this study, we evaluated 93 different compounds to find the most suitable ones for improving chromatographic quality of the signal. Because hydrogen bonding has been shown to be an important factor in analyte interactions with active sites, we mainly focused on additives with strong hydrogen bonding capabilities. Dramatic peak enhancements were achieved using compounds containing multiple hydroxy groups, such as sugars and sugar derivatives, and gulonolactone appears to be the most effective protecting agent for the most pesticides that we tested. The benefits of using analyte protectants versus alternative procedures for overcoming matrix-induced effects in quantitation include: (a) simpler procedure; (b) easier integration of peaks; (c) lower detection limits; (d) better quantitation; (e) less maintenance of the GC inlet; and (e) lower cost. However, long-term influences on the performance of the chromatographic system have yet to be established.
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Affiliation(s)
- Michelangelo Anastassiades
- US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA
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Korenková E, Matisová E, Slobodník J. Study on the feasibility of coupling large-volume injection to fast gas chromatography with mass spectrometric detection for analysis of organochlorine pesticides. J Sep Sci 2003. [DOI: 10.1002/jssc.200301269] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hajslová J, Zrostlíková J. Matrix effects in (ultra)trace analysis of pesticide residues in food and biotic matrices. J Chromatogr A 2003; 1000:181-97. [PMID: 12877171 DOI: 10.1016/s0021-9673(03)00539-9] [Citation(s) in RCA: 302] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
If one has to determine multiple residues of modem pesticides and/or other groups of (semi)polar and/or thermally unstable contaminants with a wide range of physico-chemical properties within a single analytical run, it can be complicated to obtain low limits of quantitation (LOQ), good precision as well as relevant trueness of results for all the target analytes. Matrix components, which are unavoidably present in analyzed samples (even after the thorough clean-up step), may be responsible for miscellaneous adverse affects impairing different stages of the GC and/or LC determinative step. In this review, the nature of various types of matrix effects are discussed together with suggestions for prevention, reduction and/or compensation of their occurrence when determining troublesome analytes in foods and other complex biotic matrices.
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Affiliation(s)
- Jana Hajslová
- Institute of Chemical Technology, Department of Food Chemistry and Analysis, Technická 3, Prague 6, Czech Republic.
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Zrostlíková J, Hajslová J, Godula M, Mastovská K. Performance of programmed temperature vaporizer, pulsed splitless and on-column injection techniques in analysis of pesticide residues in plant matrices. J Chromatogr A 2001; 937:73-86. [PMID: 11765087 DOI: 10.1016/s0021-9673(01)01308-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A programmed temperature vaporizer (PTV) injection technique has been recently implemented in our laboratory. In present paper its performance is compared with other GC injection techniques commonly used in trace analysis of organic contaminants. Twenty-six pesticides representing different chemical classes were selected for the study. This group comprised compounds typically subjected to discrimination in the injection port of the gas chromatograph, e.g., polar organophosphorus pesticides and thermolabile carbamates. In the first set of experiments standards in pure solvent were injected into GC systems employing different types of injection, i.e., (i) on-column, (ii) pulsed splitless, (iii) PTV solvent split, (iv) PTV splitless, and the responses of analytes were compared. Discrimination of troublesome compounds was significantly decreased with the application of PTV solvent split injection. In the second set of experiments repetitive injections of purified wheat samples were performed, with aims to evaluate the long-term stability of responses, as well as matrix effects in different stages of system contamination for each injection technique. The tolerance of the GC system to co-injected matrix components was increased in the order: on-column<pulsed splitless<PTV solvent split technique. As regards matrix effects, these were suppressed considerably with the PTV solvent split technique in comparison with pulsed splitless injection. With the latter technique after 66 injections of wheat samples relative responses (apparent recovery) reached as much as 450% for some compounds, while with the application of PTV matrix effects did not exceed 200% under the same conditions.
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Affiliation(s)
- J Zrostlíková
- Institute of Chemical Technology, Prague, Czech Republic
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