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 μm thick insulation layer in the middle separating the upper Pt-IDA electrodes (26 pairs of 400 μm long fingers, 5 μm wide with 5 μm 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 × 10−5 to 1.5 × 10−4 wt.%. The method can be considered as a less expensive alternative to the AAS determination of Fe pollutants in this ultrapure material.