SELECTIVE EXTRACTION AND DETERMINATION OF DI (2-ETHYLHEXYL) PHTHALATE IN AQUEOUS SOLUTION BY HPLC COUPLED WITH MOLECULARLY IMPRINTED SOLID-PHASE EXTRACTION

Surface Molecularly Imprinted Polymer (SMIP) for selective adsorption of di(2-ethylhexyl) phthalate(DEHP) was prepared on the surface of silica gel which was modified by aminopropyltriethoxysilane and acryloyl chloride in a two-step method. The prepared SMIP was used to prepare Molecularly Imprinted Solid-Phase Extraction (MISPE) column for selective extraction of DEHP from aqueous solution. The results suggested that MISPE column had high affinity and excellent selectivity for DEHP. And adsorption property of MISPE column was significantly superior to the commercial C18 column. The MISPE column was reusable. An analytical method MISPE-HPLC was developed for extraction and determination of the DEHP residues in environmental water samples. The results showed that the linear relationship between the peak area and the concentration of DEHP were as follow: y=2354.6x+1663.5 with a good correlation coefficient (R2=0.9997) and the detection and quantification limits reached 0.012 mg/L and 0.039 mg/L, respectively. The spiked recoveries of DEHP in river water and lake water sample were in the range from 93.3% to 102.3 % at the spiked level of 50~1000 μg/L. The Relative Standard Deviations (RSD) were less than 5.2%.