121st General Meeting of the KCS

Type Poster Presentation
Area Analytical Chemistry
Room No. Event Hall
Time 4월 19일 (목요일) 11:00~12:30
Code ANAL.P-263
Subject A Zone Fluidic-Based Automatic Water Analyzer for Chromium Monitoring
Authors Kyoung Ho Jo, Jae-Hoon Ahn, Han Ok Kim, Geum-Yong Hong1, Joo-Heon Lee1, Jong Hoon Hahn*
Department of Chemistry, Pohang University of Science and Technology, Korea
1BL Process Co., Ltd., Korea
Abstract A zone fluidic (ZF)-based automatic water analyzer has been developed for highly sensitive and selective determination of chromium (Cr). Cr is determined by measuring chemiluminescence (CL) from Cr(III)-catalyzed luminol (5-amino-2,3-dihydro-1,4-phthalizinedione) oxidation by hydrogen peroxide in basic solutions. CL reactions catalyzed by other metal ions are prevented by employing ethylenediaminetetraacetic acid (EDTA), where the interfering metal ions form complexes with EDTA faster than Cr(III). The ZF-based automatic water analyzer consists of reactors for preliminary treatment and CL reaction, a detector, and fluidic manipulation parts including a syringe pump, a multiport valve, and a tubing loop. In the tubing loop, luminol, hydrogen peroxide, and sample segments are separated by intervening air segments to prevent sensitivity decrease caused by mixing of fluid segments prior to CL detection. Sample and EDTA, by contrast, are sequentially loaded into the tubing loop without an intervening air segment, which allows mixing between sample and EDTA segments within the tubing loop such that it can make selective Cr analysis possible by masking interfering metal ions with EDTA. The analyzer for Cr determination secures a wide linear response range of 10–2000 μg/L (R2= 0.9998) and a low detection limit of 0.6 μg/L (S/N = 3). Through determinations of Cr in standard samples and real waste-water samples, we have demonstrated that this analyzer is capable of accurate (<±2%), precise (<3%), and selective Cr analysis.
E-mail jkh_20051224@postech.ac.kr