Switchable hydrophilicity solvent based homogeneous liquid-liquid microextraction for enrichment of pyrethroid insecticides in wolfberry

Abstract

A simple and sensitive homogeneous liquid–liquid microextraction based on switchable hydrophilicity solvent (SHS-HLLME) has been developed for fast enrichment and determination of pyrethroid insecticides in wolfberry samples via HPLC-UV. In HLLME, N, N-dimethylbenzylamine (DMBA) was used as SHS that can reversibly convert between water-insoluble and water-soluble states by applying CO2 as trigger. Two phase separation was easily achieved by addition of NaOH solution without need of time-consuming of salting-out or forming ionpair, greatly shortening extraction time (3 min). The influencing extraction parameters were investigated and optimized in detail. Under the optimal condition, the method shows good linearity (1.0–200 ng/mL), low limits of detection (0.2–0.5 ng/mL), desirable precision (RSD < 9.8%) and accuracy (RE < 8.7%) and acceptable extraction recovery (71.4%-94.1%). The work provides a novel alternative approach for determination of pyrethroid insecticides at the low nanogram per microliter range with desirable sensitivity.