Photodechlorination of 3,3′-dichlorobenzidine in water

✍ Scribed by Marianne C. Nyman; Ken S. Haber; Hilkka I. Kenttämaa; Ernest R. Blatchley Iii

• Book ID: 102201808
• Publisher: John Wiley and Sons
• Year: 2002
• Tongue: English
• Weight: 147 KB
• Volume: 21
• Category: Article
• ISSN: 0730-7268
• DOI: 10.1002/etc.5620210305

✦ Synopsis

Abstract

Laboratory experiments have been conducted to elucidate the photochemical behavior of 3,3′‐dichlorobenzidine (DCB) and its congeners in aquatic systems. Photodechlorination of DCB was observed in aqueous samples that were irradiated with monochromatic radiation from a variable‐wavelength laser at several wavelengths in the range 300 nm ≤ λ ≤ 360 nm. Analytical measurements performed by high‐performance liquid chromatography (HPLC) and Fourier‐transform ion cyclotron resonance (FTICR) mass spectrometry revealed that 3‐chlorobenzidine (MCB) was produced as a transient intermediate in the photodechlorination process, with subsequent photodechlorination to yield benzidine as a stable photoproduct. Data obtained from these measurements also suggest the existence of other (unidentified) reaction pathways and products. The time‐course measurements of chlorobenzidine congener concentrations and irradiance history were combined with a simple reaction model to develop estimates of reaction kinetics. Model predictions were consistent with results obtained for all wavelengths investigated.