Selective Solid Phase Extraction of Nonylphenol and Bisphenol A in Environmental and Food Samples Using Double-Molecularly Imprinted Polymer Microsphere
Double template molecularly imprinted polymer( D-MIP) was prepared by emulsion polymerization method using the nonylphenol( NP),bisphenol A( BPA) as templates,α-methyl methacrylate( MAA) as functional monomer. Then using the D-MIP as solid phase extraction materials,a method based on doublemolecularly imprinted solid phase extraction coupled with high performance liquid chromatographic fluorescence detection was developed for the determination of trace NP and BPA from environmental and food samples. The D-MIP was characterized by Fourier transform infrared spectroscopy( FT-IR) and adsorption experiments. The results showed that the saturated adsorption capacity of the D-MIP for NP and BPA was 73. 3and 97. 5 mg / g, respectively, and the relative selectivity coefficient was 2. 2 and 1. 7, respectively.Moreover,the conditions affecting extraction efficiency,such as washing conditions and desorption conditions were optimized. Under the optimal conditions,there was a good linear correlation in the concentration range of0. 01- 2. 3 mg / L with correlation coefficients( R2) greater than 0. 998 for NP and BPA. The detection limits( S /N = 3) were 0. 001 and 0. 002 mg /L. The proposed method was applied to determine NP and BPA in river water,beer and crucian carp samples. The recoveries of NP and BPA were in the range of 86. 4%- 99. 1%with the relative standard deviation less than 6. 2%. This method has good selectivity and high sensitivity and shows good prospects for the application in the enrichment and separation of NP and BPA in real samples.