Syringe-to-syringe dispersive liquid-phase microextraction solidified floating organic drop combined with high-performance liquid chromatography for the separation and quantification of ochratoxin A in food samples.

A new, simple, and rapid syringe-to-syringe dispersive liquid-phase microextraction with solidified floating organic drop was used for the separation and preconcentration of ochratoxin A from grain and juice samples before its quantification using high-performance liquid chromatography and fluorescence detection. Factors influencing the microextraction efficiency of ochratoxin A, such as sample solution pH, type and volume of organic extractant, salt concentration, number of injections, and volume of the sample, were studied and optimized. Under the optimum properties, the calibration graph showed linearity in the range of 65.0-700.0 ng/L (coefficient of determination = 0.9991). The limit of detection was 20.0 ng/L. The inter-day and intra-day relative standard deviations were in the range of 5.0-8.5%. This method was successfully applied for the quantification of ochratoxin A in grain and juice samples.