Determination of Bovine Serum Albumin by High Performance Liquid Chromatography After Rapid Extraction Using a New Magnetic Molecularly Imprinted Polymer

A novel magnetic molecularly imprinted polymer (Fe₃O₄-G/MWNT@MIP) was prepared with bovine serum albumin (BSA) as the template molecule, dopamine as the functional monomer, and magnetic ferroferric oxide-graphene-multiwalled carbon nanotubes (Fe₃O₄-G/MWNT) as carriers, and used for extraction of BSA. After the serum sample was diluted 10-fold with 10 mmol·L^-1 phosphate buffer solution (pH 6.0, containing 1.0 mmol·L^-1 NaCl), 20.0 mg of Fe₃O₄-G/MWNT@MIP was added, and the mixture was shaken for 20 min. The liquid was discarded, and the solid was washed with 5.0 mL of 10 mmol·L^-1 NaCl solution (pH 6.0), then desorbed with 2.0 mL of 0.5 mmol·L^-1 NaCl solution (pH 5.0) for 20 min. The eluate was transferred into a ultrafitration tube and centrifuged at 12 000 r·min^-1 for 20 min, and the ultrafitrate was taken for high performance liquid chromatography analysis. The results showed that, Fe₃O₄-G/MWNT@MIP had good selectivity to BSA, and the maximum adsorption capacity was 56.79 mg·g^-1. After repeated use for 20 times, the maximum adsorption capacity only reduced by 7%. The method was successfully applied to determination of BSA in calf serum. Values of recovery obtained by standard addition method were between 90.0% and 120%, and the relative standard deviations (n=7) of the measured values were less than 3.0%.