Molecularly Imprinted Polymers for Emergency Strontium-90 Urine Bioassay

The present work was focused on the preparation of polymeric submicron particles from methacrylic acid (MAA) to exploit its negative charge (COO-). The study was performed on two different molecularly imprinted polymer (MIP) particles. The initial tests were performed on MIP particles template with 17beta-estradiol (E2) and impregnated with dicyclohexano-18-crown-6 (DCH18C6). The metal ion binding characteristics of these novel particles were studied systematically using both differential pulse anodic stripping voltammetry (DPASV) and atomic emission spectrometry (AES). Our ultimate goal is to develop efficient particles for solid phase extraction of Sr 2+ from urine samples in emergency bioassay.;The study was continued by investigating on DCH18C6-MIP particles (326+/-2 nm diameter), which were template with DCH18C6, using acetone and acetonitrile (1:3 v/v) as the porogen, methacrylic acid (MAA) as the functional monomer, and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. The DCH18C6-MIP particles were impregnated with additional DCH18C6 and treated further with NaOH to attain better binding affinity for Sr2+. The effects of pH, ionic strength and amount of particles were evaluated for optimal extraction of 90Sr2+ from urine samples, as measured by liquid scintillation analysis (LSA). Precipitation and sorption studies were performed for the removal of 90Y interference. After up to 94% of 90Y were removed by sorption onto TiO2 powders, DCH18C6-MIP particles were applied for the solid phase extraction of 90Sr remaining in the urine matrix, for final LSA. The results showed up to 98% of 90Sr were bound onto NaOH-treated DCH18C6 incorporated MIP particles.