학술논문

Ultramicroband array electrode. 1. Analysis of mercury in contaminated soils and flue gas exposed samples using a gold-plated iridium portable system by anodic stripping voltammetry
Document Type
Author abstract
Source
Analytical Chemistry. July 15, 2006, Vol. 78 Issue 14, p5172, 7 p.
Subject
Coated electrodes -- Properties
Gold compounds -- Properties
Voltammetry
Language
English
ISSN
0003-2700
Abstract
The applicability of a gold-plated iridium Nano-Band array ultramicroelectrode (6 [micro]m by 0.2 [micro]m, 64-[micro]m interspacing, 100 electrode bands) in the analysis of mercury using a portable system is demonstrated by anodic stripping voltammetry in real-life samples. Optimized measurement parameters, 0.1 M HCl electrolyte, plating potential of 0 mV, and staircase scan mode were identified. The dynamic linear range is 10-180 ppb at 5-s deposition time with 1.5 [micro]C of gold plated. The experimental detection limit for [Hg.sup.2+] in 0.1 M HCl was 0.5 ppb at a deposition time of 4 min and a scan rate of 10 V/s. Real-life samples, such as flue gas exposed samples from flue gas simulators could be analyzed within 5 min using the method of standard additions. We identified a field-portable extraction procedure for soil samples using 1:1 concentrated HN[O.sub.3]/30% [H.sub.2][O.sub.2] mixture, compatible with ASV and the iridium electrode. The detection limit for soils is 1 ppm. The results obtained using ASV are in good agreement with reference values using cold vapor atomic absorption for the sample matrixes studied here. To our knowledge, this is the first mercury application using a reusable iridium array ultramicroelectrode. The portable potentiostat is less than 500 g, and together with the portable digestion method, makes the Nano-Band Explorer system field applicable.