Ultrasonic-assisted dispersive liquid-liquid microextraction based on a simple and green deep eutectic solvent for preconcentration of macrolides from swine urine samples

In this study, a simple and green deep eutectic solvent based dispersive liquid-liquid microextraction methodology had been proposed for the assessment of four macrolides in swine urine samples. Some important parameters including type and volume of extraction solvent and demulsifier solvent, sample pH, salt concentration affecting extraction efficiency were investigated. The quantitative recoveries were achieved at pH 9 and 20% (w/v) NaCl by using 0.3 mL of deep eutectic solvent consisting of choline chloride-phenol (1:2, molar ratio) and 0.3 mL of tetrahydrofuran. Under optimal conditions, the linear ranges of four macrolides were 0.5-20.0 mu g/L with correlation coefficient higher than 0.999. Limits of detection and quantification were in the ranges of 0.02-0.1 and 0.1-0.5 mu g/L, respectively. The relative recoveries for macrolides in spiked swine urine samples ranged from 80 to 93% with relative standard deviations less than 6%.