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

Based on the thiourea quenching of the chemiluminescence of Tb3+/ prulifloxacin (PUFX) sensitized KMnO4-Na2SO3 system, a convenient and rapid chemiluminescence method for the determination of thiourea was proposed. The reaction between KMnO4 and Na2SO3 brought only weak chemiluminescence, but the chemiluminescence increased sharply in the presence of sensitizer Tb3+/ PUFX. Addition of thiourea can prevent the reaction between KMnO4 and Na2SO3, thus the chemiluminescence intensity was significantly decreased. Under the optimum conditions, the calibration graphs for thiourea were linear in the range of 1.0 x 10(-7) to 4.0 x 10(-5) mol.L-1. The limit of detection was 6.4 x 10(-8) mol.L-1. 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 similar to 113.4%. The possible mechanism of sensitization and quenching was also proposed. (C) 2021 Published by Elsevier B.V.

Automated summary

A convenient chemiluminescence method for thiourea determination was proposed based on the thiourea quenching of the chemiluminescence of Tb3+/ prulifloxacin sensitized KMnO4-Na2SO3 system. The method showed linear calibration graphs in a certain concentration range with satisfactory spiked recoveries. Additionally, a possible mechanism of sensitization and quenching was proposed to explain the process.