Preparation of Roxarsone Imprinted Polymers and Its Application to Solid Phase Extraction

Molecularly imprinted polymers(MIP) with high selectivity to roxarsone(ROX) were prepared using arsanilic acid(ASA) as dummy template,2-Vinylpyridine(2-VP) as monomer,ethylene glycol dimethacrylate(EGDMA) as cross-linker.The effects of porogen,monomer and cross-linker on the recognition capability of MIP were investigated.The optimal ratio of ASA,2-VP,EGDMA,methanol-acetonitrile(1 ∶ 1,V/V) and azobisisobutyronitrile was 1 mmol ∶ 4 mmol ∶ 20 mmol ∶ 6 mL ∶ 60 mg,respectively.The maximum adsorption of MIP to ROX was 0.93 mg/g.The optimal conditions of solid phase extraction of MIP as adsorptive material for selective extraction and enrichment of ROX were: conditioning with water and acetonitrile,loading ROX in acetonitrile,washing with water and methanol,and eluting with methanol-formic acid(95 ∶ 5,V/V).The recovery of ROX on MIP cartridge was above 95% and that on NIP cartridge was only 43.1%.The prepared MIP cartridge was applied to extract and enrich ROX in pond water,and the limit of detection of ROX was 0.05 mg/L.