Highly selective determination of phenolphthalein by flow injection chemiluminescence method based on a molecular...

The phenolphthalein-imprinted polymer was prepared with methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker. Taking advantage of the quenching effect of phenolphthalein on the potassium permanganate-HCl-anhydrous alcohol chemiluminescence system, a new model was established to determine phenolphthalein by a highly selective flow injection chemiluminescence method. The traditional flow-though cell was replaced with a novel flow path using a Y-shaped polymethyl methacrylate column, through which the three reactants were injected simultaneously. The linear range of this assay was from 1.0 x 10(-8) to 1.0 x 10(-6) g/mL (r = 0.9978). The limit of detection was 8.9 x 10(-9) g/mL. The relative standard deviation for the determination of 1.0 x 10(-8) g/mL phenolphthalein solution was below 2.9% (n = 11). The proposed method was applied to the determination of phenolphthalein in real samples with satisfactory results.