1996 Volume 45 Issue 4 Pages 309-313
In this paper, we propose a novel pre-concentration method using an electric field. After concentration enhancement in a microsyringe (in a volume of 50 μl or 10 μl), the concentrated solution is injected directly to the liquid chromatography system. Because concentration and injection were done with the same syringe, threr is very little loss of sample solution. For higher concentration enhancement, this microsyringe concentration method has been performed with an electrode transfer, in which a counter electrode is transferred to another electrode during the concentration process, thereby accomplishing the electroconcentration in a very short period, i.e. a few or several minutes. A typical example is described. By using 50 μl microsyringe, an aqueous solution of 8 μM benzoic acid in 2 mM L-Arginine was concentrated with an application of 300 V for a 3 min operational period. The concentration enhancement of 3.5 μl around the electrode was 10.8 times the original solution.
