Development of a simple column electrode for sensitive and rapid coulometry.

A simple column electrode, S-CE, with a glassy carbon fibers working electrode stuffed into a Teflon tube was developed. The current-potential curves for the reductions of [Fe(CN)(6)](3-) and Fe(3+) observed at the S-CE were analyzed based on a theory for those at an ordinary column electrode. A quantitative electrolysis was performed at the S-CE rapidly within 20 s. An accurate and precise coulometric determination could be attained at the S-CE even with a fairly dilute solution. For example, coulometric reductions of 5 x 10(-5) and 5 x 10(-6) M Fe(3+) were attained with efficiencies (n = 5) of 99.7 +/- 0.2 and 101.9 +/- 1.1%, respectively.