Quantitatively chemo-fluorometry diagnostic to nitrite ion in ultrasound aqueous medium containing 2,3-diaminonaphthalene

Abstract

When ultrasound (US) was exposed in aqueous solution of 2,3-diaminonaphthalene (DAN) in air atmosphere, fluorescent spectra were measured after different US exposure times. US exposure was carried out at 43, 141 and 500kHz with constant out-put power of 50W. It was found that the DAN fluorescent having 410nm emission maximum was decreased as the US exposure was increased, but, the fluorescent at 505nm for 1-[H]-naphthotriazole (NTTA) was increased. This exhibited that the DAN fluorophore was converted to NTTA by the US exposure, especially at 141kHz. The calibration analysis was indicated the DAN framework was changed to triazole ring from DAN and NO2− ion. As a result, the characteristic NTTA fluorescent became probe to NO2− ion in US medium. The chemo-fluorometry of the DAN was original work to be useful detecting to nitric acid ion in US exposure solution.