Determination of tetracyclines by novel singlet-oxygen mediated cerium(IV) chemiluminescence.

Novel chemiluminescence mechanisms of cerium(IV) and five tetracyclines in the absence and presence of Tween 80 are reported. The role of tetracyclines in the present chemiluminescence system was studied in detail by ultraviolet spectra and the singlet oxygen1O2probe 2-methyl-6-(4-methoxyphenyl)-3, 7-dihydroimidazo[1,2-a]-pyrazin-3-one hydrochloride. It is the first report that cerium(IV) reacted with tetracyclines producing singlet oxygen1O2after breaking the organic skeleton and decomposition of peroxyacetic acid in the absence of the surfactant Tween. Furthermore, by examining the effects of sodium azide and the chemiluminescence spectra, the results indicated that the maximum chemiluminescence emission at approximately 480 nm was due to dimer emission of singlet oxygen1O2from the reaction between cerium(IV) and tetracyclines as well as the reaction of cerium(IV) and Tween 80, respectively. Moreover, the chemiluminescence signals were unaffected when the reaction was performed under anaerobic condition, indicating that dissolved oxygen was independent of this system. Under the optimal conditions, the analytical characteristics and parameters of the cerium(IV)-Tween 80-tetracyclines chemiluminescence system were investigated. The present method was successfully employed for the determination of tetracyclines in milk. [ABSTRACT FROM PUBLISHER]