Rapid on-line microextraction of neutral analytes in plastic-bottled beverages through ultrasound-assisted push/pull perfusion hollow-fiber liquid-liquid-liquid microextraction

In this study we developed a rapid sample cleanup and enrichment procedure combining ultrasound-assisted push/pull perfusion technique and hollow-fiber liquid-liquid-liquid microextraction for online extraction of neutral analytes in liquid samples. To overcome the problems of long extraction times for neutral analytes and fluid loss or gain across the porous hollow fiber membrane to or from the donor phase, we used an ultrasonic probe to accelerate the mass transfer and a push/pull syringe pump as the driving source to perfuse the acceptor phase and decrease the perfusion pressure, permitting on-line coupling of hollow-fiber liquid-liquid-liquid microextraction to HPLC. We tested the extraction of three low- to transitional-molecular-weight phthalate esters as model neutral compounds from plastic-bottled waters and plastic-bottled functional beverages. Good linearity existed in the range 0.1-100 ng mL− 1 with a precision of less than 5.8% and limits of detection in a range 0.01-0.02 ng mL− 1. This developed micro-extraction method allowed the sensitive, simple, and rapid determination of target phthalate esters in bottled drinks with a sampling time of just 2 min.