ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Application of mixed solvents for elution of organophosphate pesticides extracted from raw propolis by matrix solid-phase dispersion and analysis by GC-MS

Kati Medina-Dzul, David Muñoz-Rodríguez, Yolanda Moguel-Ordoñez, and Cristian Carrera-Figueiras

Cuerpo Académico de Química Fundamental y Aplicada, Facultad de Ingeniería Química, Universidad Autónoma de Yucatán, Periférico Norte km. 33.5, Tablaje catastral 13615, Colonia Chuburná de Hidalgo Inn, C.P. 97203, Mérida, Yucatán, México

E-mail: david.mr@uady.mx

Abstract: The excessive application of organophosphate pesticides (OPPs) in crop fields close to hives and its application in beekeeping practices are potential sources of contamination of propolis. Pesticides were extracted from raw propolis by matrix solid-phase dispersion. Because of the complex chemical composition of propolis, binary solvent mixtures based on acetonitrile and a relatively non-polar solvent in different proportions were tested for the selective elution of OPPs. The effect of mixed solvents on clean-up was evaluated by GC-MS and the main interfering compounds co-eluted with pesticides were identified. In addition, three volumes of the solvent mixture and the volume of the sample were evaluated in an experimental factorial design. The final experimental conditions were 1 mL of dissolved propolis and 8 mL of acetonitrile/dichloromethane (g4 _r = 25: 75). Mean recoveries ranged from 55 % to 96 % (relative standard deviation < 8 %) with an inter-day precision lower than 24 %. The proposed method was applied to the analysis of real samples obtained from local beekeepers.

Keywords: GC-MS – matrix solid-phase dispersion – propolis – pesticide residues – mixed solvents

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-014-0600-4

Chemical Papers 68 (11) 1474–1481 (2014)