Development of a new microextraction method based on elevated temperature dispersive liquid-liquid microextraction for determination of triazole pesticides residues in honey by gas chromatography-nitrogen phosphorus detection

In the present study, a rapid, highly efficient, and reliable sample preparation method named "elevated temperature dispersive liquid-liquid microextraction" followed by gas chromatography-nitrogen-phosphorus detection was developed for the extraction, preconcentration, and determination of five triazole pesticides (penconazole, hexaconazole, diniconazole, tebuconazole, and difenoconazole) in honey samples. In this method the temperature of high-volume aqueous phase was adjusted at an elevated temperature and then a disperser solvent containing an extraction solvent was rapidly injected into the aqueous phase. After cooling to room temperature, the phase separation was accelerated by centrifugation. Various parameters affecting the extraction efficiency such as type and volume of the extraction and disperser solvents, temperature, salt addition, and pH were evaluated. Under the optimum extraction conditions, the method resulted in low limits of detection and quantification within the range 0.05-0.21 ng g(-1) in honey (15-70 ng L-1 in solution) and 0.15-1.1 ng g(-1) in honey (45-210 ng L-1 in solution), respectively. Enrichment factors and extraction recoveries were in the ranges of 1943-1994 and 97-100%, respectively. The method precision was evaluated at 1.5 ng g(-1) of each analyte, and the relative standard deviations were found to be less than 4% for intra-day (n = 6) and less than 6% for inter-days. The method was successfully applied to the analysis of honey samples and difenoconazole was determined at ng g(-1) levels. (C) 2014 Elsevier B.V. All rights reserved.