Determination of hydralazine with flow injection chemiluminescence sensor using molecularly imprinted polymer as recognition element

A novel flow injection chemiluminescence (CL) sensor for hydralazine determination using molecularly imprinted polymer (MIP) as recognition element is reported. Hydralazine–MIP was prepared through non-covalent copolymerization using methacrylic acid (MAA) monomer, hydralazine template and ethylene glycol dimethacrylate (EGDMA) cross-linker. Particles of the MIP were packed into a v-shape glass tube for on-line adsorption of the analyte of hydralazine. The adsorbed hydralazine could be sensed by its great enhancing effect on the CL reaction between luminol and periodate. The CL intensity is linear to hydralazine concentration in the range from 2 × 10−9 to 8 × 10−7 g/mL. The detection limit is 6 × 10−10 g/mL (3σ) and the relative standard deviation is 2.8% (n = 7) for 8 × 10−9 g/mL hydralazine. The selective experiment showed that the selectivity and sensitivity of the CL method could be greatly improved when MIP was used as recognition element in the flow-injection CL sensor. The sensor was reversible and reusable. It could be used for more than 100 times. It has been used directly to determine the hydralazine in human urine.