A preconcentration method for analysis of neonicotinoids in honey samples by ionic liquid-based cold-induced aggregation microextraction.

A preconcentration approach based on ionic liquid-based cold-induced aggregation microextraction for determination of neonicotinoid insecticide residues in honey samples before high-performance liquid chromatographic analysis has been developed. Room temperature ionic liquid [C4MIM][PF6] (extraction solvent) and SDS (emulsifier) was used for extraction of the target analytes. The parameters affecting the extraction efficiency were optimized. The optimum microextraction conditions were 200µL room temperature ionic liquids [C4MIM][PF6] containing 0.05molL(-1) SDS, 0.75g sodium carbonate, vortex agitation speed of 1800rpm for 30s and centrifugation at 3500rpm for 10min. Under optimum conditions, the high enrichment factors of 200 could be obtained, leading to low limit of detection (0.01µgL(-1) for all analytes) with the relative standard deviations lower than 2.68% and 5.38% for retention time and peak area, respectively. Good recoveries for the spiked target neonicotinoids at three different concentrations of honey samples were obtained in 86-100% and relative standard deviations were lower than 8.1%. The results demonstrated that the proposed method can be used as an alternative powerful method for the simultaneous determination of the studied insecticides in real honey samples.