Ionic Liquid-Based Dispersive Liquid–Liquid Microextraction Following High-Performance Liquid Chromatography for the Determination of Fungicides in Fruit Juices

Abstract

This paper described an ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLME) combined with high-performance liquid chromatography (HPLC) method to determine fungicides in fruit juices. In this method, 1-hexyl-3-methyli-midazolium hexafluorophosphate (HMIMPF₆) was used as extraction solvent, which dispersed into the fruit juices under vigorously shaking with the vortex. The effects of experimental parameters, such as extraction solvent volume, disperser solvent and its volume, vortex time, centrifugation time, sample pH, on the extraction efficiency were investigated. Under the optimum conditions, the linear correlation coefficients ranged from 0.9902 to 0.9979 for concentration levels of 0.02–2 mg l⁻¹, the extraction recoveries were ranged 66.2–92.9 % except pyrimethanil (39.5–44.6 %), The relative standard deviations (RSDs; n = 6) ranged from 2.2 % to 11.6 %, and the limits of detection (LODs) for the fungicides were between 3.1 and 10.2 μg l⁻¹. Two real samples including apple and grape juices, spiked at two concentration levels were analyzed and yielded recoveries ranging from 71.3–93.1 % and 65.4–87.7 %, respectively.