Determination of tertiary amines based on pH junctions and field amplification in capillary electrophoresis with electrochemiluminescence detection

A stacking approach based on pH junction and field amplification has been developed for determining amines by capillary electrophoresis (CE) with electrochemiluminescence (ECL) detection. A two‐electrode configuration was employed with an indium/tin oxide‐coated glass as a working electrode and a platinum wire as a pseudoreference electrode. The ECL system also contains a flow cell (poly(dimethylsiloxane)‐aluminum oxide) that was made from a mixture of Sylgard 184 silicone elastomer, a curing agent, and aluminum oxide. In order to improve the sensitivity of the present CE‐ECL system using tris(2,2'‐bipyridyl) ruthenium(II) (Ru(bpy)32+), a stacking approach based on pH junctions and field amplification has been tested for the analysis of triethylamine (TEA), tripropylamine (TPA), and tributylamine (TBA). Once amines (cations) prepared in citric acid solution (pH