Author(s)

Abir Kouzayha, Abdul Rahman Rabaa, Mohamad Al Iskandarani, Daniel Beh, Hélène Budzinski, Farouk Jaber

Analysis of Pesticides and Organic Pollutants Laboratory LAPPO, Lebanese Atomic Energy Commission LAEC, National Council for Scientific Research CNRS, Beirut, Lebanon.
ISM-LPTC-UMR 5255 (Laboratory of Physico- and Toxico-Chemistry), CNRS, Université Bordeaux, Talence, France.
Laboratory of Analysis of Organic Compounds (509), Faculty of Sciences I, Lebanese University, Beirut, Lebanon.

A new multi-residue method based on solid-phase extraction (SPE) with centrifugation was developed for determination and quantitation of 67 pesticides in water samples. Two SPE cartridges were tested: Chromabond C18 and Oasis HLB. Parameters that influence the extraction efficiency such as the eluent volume, the sample loading volume, the addition of organic solvent to water sample, sorbent drying and elute concentration were optimized. The innovation of this work was the examination of the use of a centrifugation technique in both the drying and elution steps. When combined with centrifugation, the volume of the elution solvent was reduced to 2 mL and the time for sorbent drying decreased also to 10 min under vacuum. Under the optimized conditions, this method showed good recoveries higher than 65% - 68% for the 67 analyzed pesticides using the C₁₈ and HLB cartridges with relative standard deviations lower than 9.7% - 12.3%. Limits of quantification were between 2 and 20 ng.L^–1. The simplicity of the described method, use of less of organic solvent, short procedure time, and good recoveries demonstrate the advantages of this environmentally friendly approach for routine analysis of numerous samples.

Multi-Residue; Pesticides; Solid-Phase Extraction; Centrifugation; Gas Chromatography-Mass Spectrometry

A. Kouzayha, A. Rahman Rabaa, M. Al Iskandarani, D. Beh, H. Budzinski and F. Jaber, "Multiresidue Method for Determination of 67 Pesticides in Water Samples Using Solid-Phase Extraction with Centrifugation and Gas Chromatography-Mass Spectrometry," American Journal of Analytical Chemistry, Vol. 3 No. 3, 2012, pp. 257-265. doi: 10.4236/ajac.2012.33034.