Concentration of phthalate esters by polymer-mediated extraction

Abstract

Polymer-mediated extraction based on the thermoresponsive precipitation of poly(N-isopropylacrylamide) (PNIPAAm) was successfully applied to the efficient concentration (ca. 100-folds) of phthalate esters in water. With the use of 0.05 g of polymer against a 10 ml sample, the recoveries of di(2-ethylhexyl)phthalate (DEHP) and dibutylphthalate (DBP) were 98 and 82%, respectively. After extraction, μg/l-levels of DEHP and DBP in tap water, physiological saline, and mineral water samples were successfully determined by HPLC with ultra-violet spectrophotometric detection. The relative standard deviation in the determination of 39 μg/l DEHP (n=5) was 3%.