On-line Determination of Trimethoprim in Human Serum by Molecularly Imprinted Monolithic Column with Melamine Employed as Analogue Template
A molecularly imprinted monolithic column being capable of selectively adsorbing trimethoprim(TMP) was synthesized by in situ polymerization method.During the polymerization process,melamine was employed as analogue template,and methacrylic acid as functional monomer,ethylene glycol dimethacrylate as cross linker,polyethylene glycol 400(PEG400) as porogenic agent,respectively.The change of recognition ability for MIP column towards TMP was validated under different kinds of mobile phase compositions in a high performance liquid chromatographic(HPLC) system.Experimental results showed that MIP column could completely retain TMP under mobile phases of methanol,acetonitrile or water.TMP was selectively adsorbed in MIP column under methanol-water(80∶20,V/V),then the hydrophobic impurities were further erased by changing the mobile phase to methanol,and finaly,the TMP peak was obtained in the elution step of with ammonia water-methanol(2.5∶97.5,V/V).Online determination of TMP in human serum was performed in HPLC system with the imprinted column employed as chromatography column.The linear regression equation obtained was determined as A=42.8-3.03(r=0.9994) with the linear range of 8.32-93.8 mg/L and a limit of detection of 0.145 mg/L.