Anal. Chem. 1902, 6 4 , 427-434
427
Development and Characterization of a Titanium Dioxide-Based Semiconductor Photoelectrochemical Detector Garrett N. Brown,+J o h n W. Birks, and Carl A. Koval* Department of Chemistry and Biochemistry and Cooperative Institute for Research in Environmental Sciences (CIRES), Campus Box 216, University of Colorado, Boulder, Colorado 80309-0216
on an anodized titanium substrate (Ti0.J electrode with detections limits ranging from 1.6 to 210 c ~ for g aniline and benzyl alcohol, re~pective1y.l~ Our study was undertaken with the expectation that oxide production parameters could be varied to provide a significant enhancement in detector response. Our investigations of photoelectrochemical detection were prompted by our interest in developing spatially-resolved detection methods for whole column detection (WCD) chrom a t o g r a p h ~ . ~Light-addressable ~-~~ detection12J4could potentially be achieved by scanning a light beam along the length of a transparent HPLC column containing a semiconductor electrode in the form of a wire or coating on the column wall. Such a system requires that the dark current be nearly zero when compared to the total current measured during sitespecific illumination. It is important to note that only a small fraction (
