Directly suspended droplet microextraction for the analysis of fungicides

Abstract

In the proposed method, a free microdroplet of extraction solvent was placed on the top center of the aqueous sample while the solution was agitated with a stirring bar on the bottom of the sample vial. After extraction, the sample vial was cooled in an ice bath for 2 min. The solidified droplet was transferred into a conical vial and melted quickly at room temperature. Based on preliminary studies, 1-dodecanol was selected as the extraction solvent. Effective parameters such as the type and volume of organic solvent, stirring speed, extraction time, sample temperature and salt effect were optimized. Under the optimized conditions, the enrichment factors of fungicides varied between 103 and 175. Based on a signal-to-noise ratio of 3, the limits of detection in this method ranged between 1.01 and 1.49 μg L-1. Linearity was obtained in the concentration range of 5-2000 μg L-1 yielding correlation coefficients (r) >0.9985. Good reproducibility and recovery were also obtained. © The Author [2013].