CCT SANTA FE   20441
CENTRO CIENTIFICO TECNOLOGICO CONICET - SANTA FE
Centro Científico Tecnológico - CCT
congresos y reuniones científicas
Título:
Large Volume Injection in gas chromatography by the TOTAD interface operating under vacuum conditions: application to pesticide residue analysis in water
Autor/es:
ÁLVARO ARAGÓN, ROSA. M. TOLEDANO, SARA GEA, JUAN C. ANDINI; SILVINA M. ADDONA, ANA M. VÁZQUEZ, JESÚS VILLÉN
Lugar:
Montevideo
Reunión:
Workshop; 3rd Latin American Pesticide Residue Workshop (LAPRW2011) ? Pesticides in Food and Environmental Samples; 2011
Resumen:
The TOTAD interface, first described in 1999 (1), is a totally automated interface suitable for the large volume injection (LVI) of polar and non-polar solvent, and consequently for on-line liquid chromatography-gas chromatography (LC-GC) when LC is carried out in normal as well as in reversed phased. LVI in GC and on-line LC-GC are techniques considered appropriate to analyse compounds present at trace level concentrations in complex matrix, as food or environmental samples. Different analytical methods by LVI and LC-GC using the TOTAD interface have been developed (2, 3) and several modifications have been introduced to the TOTAD interface from the initial model to the last one (4) to achieve a better performance of the system and to get a much more robust system. In the present work we evaluate the performance of the TOTAD interface under a vacuum system. Using this new operation mode of the TOTAD interface, solvent elimination takes place in evaporative mode by a very low helium flow combined with the vacuum system. In this way a considerable reduction of helium consumption, about 90 %, is achieved. The TOTAD interface operation mode modifications do not affect the thermal desorption and cleaning step. This new operation mode of the TOTAD interface was applied to analyse pesticides in water samples by large volume injection in GC. Pesticides are essential in modern agriculture to control pests and to increase harvest productivity; however due to their potentially dangerous effects on human health, it is necessary to control pesticide residues in water and foods with the purpose to minimize risk to consumers. For this reason it is important to have powerful analytical methods to achieve the required sensitivity. The new operation mode of the TOTAD interface improves the sensitivity of the method (5) allowing to achieve this goal. References (1) Pérez, M., Alario, J., Vázquez, A., & Villén, J. On-line reversed phase LC-GC by using the new TOTAD (Through Oven Transfer Adsorption Desorption) Interface: Application to parathion residue analysis. J. Microcolumn Sep., 1999, 11, 582-589. (2) Cortés, J.M., Sánchez, R., Díaz-Plaza, E.M., Villén, J. Vazquez, A. Large Volume GC Injection for the Analysis of Organophosphorus Pesticides in Vegetables Using the Through Oven Transfer Adsorption Desorption (TOTAD) Interface. J. Agric. Food. Chem., 2006, 54, 1997-2002. (3) Díaz-Plaza, E.M., Cortés, J.M., Vazquez, A., Villén, J. Automated determination of pesticide residues in olive oil by on-line reversed-phase liquid chromatography?gas chromatography using the through oven transfer adsorption desorption interface with electron-capture and nitrogen?phosphorus detectors operating simultaneously. J. Chromatogr. A, 2007, 1174, 145?150 (4) Cortés, J.M., Toledano, R.M., Andini, J.C., Villén, J., Vázquez, A. Chapter 8. Chromatography, Types, techniques and Methods. (5) Toledano, R.M., Cortés, J.M., Andini, J.C., 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?4742.