Ultrasonic degradation of diaminobenzidine in aqueous medium

Louis-Marly Kwedi-Nsah; Takaomi Kobayashi

doi:10.1016/j.ultsonch.2018.11.007

Ultrasonic degradation of diaminobenzidine in aqueous medium

Ultrason Sonochem. 2019 Apr:52:69-76. doi: 10.1016/j.ultsonch.2018.11.007. Epub 2018 Nov 7.

Authors

Louis-Marly Kwedi-Nsah¹, Takaomi Kobayashi²

Affiliations

¹ Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan.
² Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188, Japan. Electronic address: takaomi@vos.nagaokaut.ac.jp.

PMID: 30528487
DOI: 10.1016/j.ultsonch.2018.11.007

Abstract

By using 500 kHz high frequency ultrasound (US), 3,3'-diaminobenzidine (DAB) was treated at pH 2 under air atmosphere. The US effect of DAB absorption at 280 nm was composed at 43 and 141 kHz for the detection of fluorescence. When 100 W of US power was used, the DAB absorption band decreased with exposure time. It was noted that, a new absorption broad band at 350 nm-500 nm appeared only under 141 and 500 kHz. Also, fluorescence spectra of the treated DAB were measured when excited at 370 nm. Increasing US exposure time resulted to a broad emission band at 478 nm, indicating that 1H,1'H-5,5'-Bibenzotriazole (BBT) was produced by US exposure at 500 kHz. This product was confirmed by NMR spectroscopy to be a triazine ring formed from NH₂ proton in DAB, due to the formation of nitrite ions in the US aqueous medium at 500 kHz. Hence, DAB was degraded while BBT was formed.

Keywords: Bibenzotriazole; Cavitation; Diaminobenzidine; Fluorometry; Nitrite; Ultrasound.