Development of Specific LC-ESI-MS/MS Methods to Determine Bifenthrin, Lufenuron, and Iprodione Residue Levels in Green Beans, Peas, and Chili Peppers Under Egyptian Field Conditions Anna A. Bletsou & Ahmad H. Hanafi & Marilena E. Dasenaki & Nikolaos S. Thomaidis Received: 4 June 2012 / Accepted: 20 September 2012 / Published online: 5 October 2012 # Springer Science+Business Media New York 2012 Abstract The dissipation of bifenthrin, lufenuron, and ipro- dione was studied in green beans, peas, and chilli peppers under Egyptian field conditions. For this purpose, three specific and one multi-analyte liquid chromatography- electrospray ionization-tandem mass spectrometry methods were developed and validated according to SANCO guide- lines for the determination of bifenthrin, iprodione, and lufenuron residues in the selected commodities. Sample preparation was carried out by the QuEChERs approach, and determination was performed in positive ionization mode for iprodione and bifenthrin and in negative mode for lufenuron. Optimization of the ionization parameters and the chromatographic conditions was performed for each method developed. All methods showed satisfactory perfor- mance criteria. Linear dynamic range, limits of detection (LOD) and quantification (LOQ), precision, recovery, and matrix effects were estimated, and the calculated LODs were in the micrograms-per-kilogram range, namely 0.14, 0.61, and 1.4 μg/kg for bifenthrin, lufenuron, and iprodione, respectively. Field trials were carried out in one of the biggest farms in Egypt (Blue Nile) that exports significant quantities of vegetables to the European Union (EU) countries. All the examined pesticides showed high degra- dation rates. The t 1/2 values for bifenthrin were 3.3, 2.1, and 9.6 days in green beans, peas, and chili peppers, respective- ly. For iprodione, they reached 2.4 and 14.4 days in green beans and peppers. Furthermore, the calculated pre-harvest interval (PHI) values, according to the maximum residue limits set by EU, were 0, 4, and 0 days for bifenthrin in green beans, peas, and peppers, respectively, and for ipro- dione, 2 days in green beans and 0 days in peppers. In case of lufenuron, no t 1/2 and PHI were estimated as no residues were found in all pea samples. Keywords Pesticides . Vegetables . LC-MS/MS . Degradation rate . Pre-harvest intervals (PHI) Introduction During the last years, the amount of crops imported to the European Union (EU) from Egypt is constantly increasing. According to Food and Agriculture Organization (FAO), the export quantities (tons) of Egypt in 2009 for beans, peas, and chilies were 3,447, 7,471, and 1,160 tons, respectively (FAO 2009). Europe is considered to be the major market for the majority of the Egyptian crops. Egypt, due to its geographical position and agro-climatic conditions, has a significant advantage in the production of horticultural com- modities; however, every crop imported to the EU should comply with the legal limits set within the EU, concerning the levels of residual pesticides in foods (Hanafi et al. 2010). Electronic supplementary material The online version of this article (doi:10.1007/s12161-012-9515-2) contains supplementary material, which is available to authorized users. A. A. Bletsou : M. E. Dasenaki : N. S. Thomaidis (*) Laboratory of Analytical Chemistry, Department of Chemistry, Faculty of Science, University of Athens, Panepistimiopolis Zographou, 15771 Athens, Greece e-mail: ntho@chem.uoa.gr A. H. Hanafi Plant Protection Department, Faculty of Agriculture, Ain Shams University, P.O. Box 68, Hadayek Shoubra, Cairo 11241, Egypt Food Anal. Methods (2013) 6:1099–1112 DOI 10.1007/s12161-012-9515-2