Bio-dispersive liquid liquid microextraction based on nano rhamnolipid aggregates combined with molecularly imprinted-solid phase extraction for selective determination of paracetamol in human urine samples followed by HPLC

Abstract

An analytical method, molecular imprinting solid-phase extraction (MI-SPE) combined with bio-dispersive liquid–liquid microextration (Bio-DLLME), was established to extraction of the paracetamol from human urine samples. In this research, paracetamol was first extracted from urine sample into bioaggregates that composed of rhamnolipid biosurfactants as an extraction solvent. The clean-up of the extract by solid phase extraction was carried out by directly adding extract solution into the cartridge. The pH of the solution was adjusted to 8 using 50 mM phosphate buffer. Finally, the analyte retained on the column was eluted with 1.0 mL methanol and injected into the liquid chromatography system for quantitative analysis. This protocol significantly increased the recoveries and enrichment of the paracetamol. Under the optimize conditions, the proposed method provided a good linearity in the range of (1–200 μg L−1), low limits of detection (0.33 μg L−1) and quantification (0.96 μg L−1) and good extraction repeatabilities (relative standard deviations below 3.54%, with three replicates for each concentration value). The percent of the extraction recovery for paracetamol was 96–103.8%. The enrichment factor value of the extraction procedure was 368.