SAMPLE STACKING USING FIELD-AMPLIFIED SAMPLE INJECTION IN CAPILLARY-ZONE-ELECTROPHORESIS IN THE ANALYSIS OF PHENOLIC-COMPOUNDS

This paper discusses a simple on-column concentration with a field-amp lified injection technique, using eleven US Environmental Protection A gency (EPA) priority phenols as model compounds. The capillary dimensi ons (length and internal diameter) for enhancing the on-column enrichm ent for phenolic compounds are studied. Under the proposed operational conditions, the detection limits (SIN=3) were in the ppb range, and t he relative standard deviations for the compounds were between 1.4 and 8.8%. Field-amplified injections are preferred to off-line preconcent ration methods because of their simplicity, rapidity and high enrichme nt factors. (C) 1997 Elsevier Science B.V.