Determination of thiourea by terbium (III)/ prulifloxacin sensitized potassium permanganate-sulfite chemiluminescence with quenching method.

Based on the thiourea quenching of the chemiluminescence of Tb/ prulifloxacin (PUFX) sensitized KMnO-NaSO system, a convenient and rapid chemiluminescence method for the determination of thiourea was proposed. The reaction between KMnO and NaSO brought only weak chemiluminescence, but the chemiluminescence increased sharply in the presence of sensitizer Tb/ PUFX. Addition of thiourea can prevent the reaction between KMnO and NaSO, thus the chemiluminescence intensity was significantly decreased. Under the optimum conditions, the calibration graphs for thiourea were linear in the range of 1.0 × 10 to 4.0 × 10 mol•L. The limit of detection was 6.4 × 10 mol•L. The method was applied satisfactorily to the determination of thiourea in tap water, lake water and rice noodles and the spiked recoveries were between 104.7 ~ 113.4%. The possible mechanism of sensitization and quenching was also proposed.