Electrophoretic separations with polyether ether ketone capillaries and capacitively coupled contactless conductivity detection

Polyether ether ketone (PEEK) capillaries were found to be compatible with capacitively-coupled contactless-conductivity detection ((CD)-D-4). Detection limits in the order of 10(-7) M were obtained with (CD)-D-4 employing a high excitation voltage (HV-(CD)-D-4) for inorganic cations and anions. The organic polymer capillary shows a relatively low electroosmotic flow of 2.6(.)10(-4) CM2 V-1 s(-1). Thus inorganic anions and slower organic anions can be separated with a PEEK capillary in a single run without flow modifier. This feature also enables the analysis of both, cations and (fast and slow) anions, in a sample in two subsequent runs just by reversing the polarity or in a single run if dual opposite end injection is employed. (C) 2002 Elsevier Science B.V. All rights reserved.