Direct Analysis of Oxidizing Agents in Aqueous Solution with Attenuated Total Reflectance Mid-Infrared Spectroscopy and Diamond-like Carbon Protected Waveguides

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• 作者：Markus Janotta ; Frank Vogt ; Hannes-Stefan Voraberger ; Wolfgang Waldhauser ; Jü ; rgen M. Lackner ; Christoph Stotter ; Michael Beutl ; and Boris Mizaikoff
• 刊名：Analytical Chemistry
• 出版年：2004
• 出版时间：January 15, 2004
• 年：2004
• 卷：76
• 期：2
• 页码：384 - 391
• 全文大小：297K
• 年卷期：v.76,no.2(January 15, 2004)
• ISSN：1520-6882

文摘

A novel approach for the direct detection of oxidizingagents in aqueous solution is presented using diamond-like carbon (DLC) protected waveguides in combinationwith attenuated total reflectance (ATR) mid-infrared spectroscopy. Pulsed laser deposition was applied to producehigh-quality DLC thin films on ZnSe ATR crystals withthicknesses of a few 100 nm. Scanning electron microscopy and X-ray photoelectron spectroscopy has been usedto investigate the surface properties of the DLC filmsincluding the sp³/sp² hybridization ratio of the carbonbonds. Beside excellent adhesion of the DLC coatings toZnSe crystals, these films show high chemical stabilityagainst strongly oxidizing agents. IR microscopy wasutilized to compare differences in the chemical surfacemodification of bare and protected ATR waveguides whenexposed to hydrogen peroxide, peracetic acid, and peroxydisulfuric acid. The feasibility of DLC protectedwaveguides for real-time concentration monitoring ofthese oxidizing agents was demonstrated by measuringcalibration sets in a concentration range of 0.2-10%.Additionally, principal component regression has beenapplied to analyze multicomponent mixtures of hydrogenperoxide, acetic acid, and peracetic acid in aqueoussolution. Due to high chemical stability and accuratemonitoring capabilities, DLC protected waveguides represent a novel approach for directly detecting oxidizingagents in aqueous solution with promising potential forindustrial process analysis.