APPLICATION OF REDOX CYCLING ENHANCED CURRENT AT AN INTERDIGITATED ARRAY ELECTRODE FOR IRON-TRACE DETERMINATION IN ULTRAPURE SPECTRAL CARBON

Vertically arranged interdigitated array (IDA) electrodes with a continuous Pt-film basis and a 0.5 mu m thick insulation layer in the middle separating the upper Pt-IDA electrodes (26 pairs of 400 mu m long fingers, 5 mu m wide with 5 mu m gaps) from the Pt-basis were applied for Fe trace analysis in ultrapure spectral carbon. The testing with spiked samples as well as comparison of results with those obtained by independent graphite-furnace atomic absorption spectrometry (AAS) proved the reliability of the proposed sample preparation procedure and IDA signal generation in the range of Fe content 1 X 10(-5) to 1.5 X 10(-4) wt.%. The method can be considered as a less expensive alternative to the AAS determination of Fe pollutants in this ultrapure material.