GRADIENT FLOW-INJECTION AMPEROMETRY BASED ON INDUCED RETENTION BY THEDETECTOR COATING

A novel approach for enhancing the selectivity of amperometric flow-in jection systems is described. This strategy relies on the use of coate d electrodes to induce longer residence rimes for the target analyte ( within the detector) compared to the interfering species. Selective me asurements of the analyte are thus performed on the tailing edge of it s peak, after passage of the interfering species from the detector. Su rface coatings with different permeability properties, including charg e-exclusion Nafion or hydrophobic lipid and alkanethiol films are thus used to retain and selectively detect counterionic or nonpolar analyt es, after the elution of co-ionic and polar interferences, respectivel y, from the detector.