STRIPPING VOLTAMMETRY OF BIOLOGICALLY-ACTIVE ORGANIC-COMPOUNDS AS HOST-GUEST COMPLEXES AT ELECTRODES MODIFIED WITH CROWN-ETHER

Procedures for determining the biologically active organic compounds I oxynil, Prefix, Sayfos, Cythioate, and Karbation by stripping voltamme try using carbon-paste electrodes modified with dibenzo-18-crown-6 (DB 18C6) or dibromo-DB18C6 crown ether were developed. The selectivity an d sensitivity were improved by using a preconcentration of organic mol ecules as host-guest complexes at the electrode. The pesticide content was monitored by the oxidation peaks of Karbation and Ioxynil and by the peak current corresponding to the formation of mercury mercaptide for the S-containing compounds. The determination limits of the proced ures suggested are 4.0 x 10(-9), 4.6 x 10(-7), 3.8 x 10(-8), 8.0 x 10( -8), and 9.0 x 10(-8) M for the pesticides Karbation, Prefix, Ioxynil, Sayfos, and Cythioate, respectively.