Molecularly imprinted on-line solid-phase extraction combined with chemiluminescence for the determination of pazufloxacin mesilate

A novel molecularly imprinted polymer solid-phase extraction (MISPE) with flow-injection chemiluminescence (CL) was developed for the determination of pazufloxacin mesilate (PZFX). The molecularly imprinted polymer (MIP) was synthesized by using PZFX as the imprinting molecule. A glass tube packed the particles of the MIP was employed as MISPE micro-column, which was connected into the sampling loop of the eight-way injection valve for on-line selective preconcentration and extraction of PZFX. The eluent of acetonitrile:acetic acid (9:1, v:v) was used as carrier for eluting the adsorbed PZFX to react with the mixture of cerium(IV) and sodium sulfite in the flow cell to produce strong CL. The relative intensity of CL was linear to PZFX concentration in the range from 2.5 × 10⁻⁹ to 2.5 × 10⁻⁷ g mL⁻¹. The limit of detection was 7 × 10⁻¹⁰ g mL⁻¹ (3 σ) and the relative standard deviation for 5 × 10⁻⁸ g mL⁻¹of PZFX solution was 3.7% (n = 7). This method has been applied to the determination of PZFX in human urine.