The electrophoretic behavior of a surfactant-free carboxylamidine polystyrene latex is examined using the fingerprinting approach. The mobility is mapped in four 1:1 electrolytes (KCl, NaCl, KNO3, and NaNO3) as a function of pH and p lambda, the logarithm of the bulk solution conductivity in mu S/cm. The overall similarity of the diagrams suggests that, to a first approximation, the salt systems examined behave as indifferent electrolytes. Small effects arising from specific-ion adsorption, and differing for each salt, are shown by the meandering of the line of zero mobility in the pH-p lambda plane. The measured mobilities and the calculated Smoluchowski zeta-potentials show a maximum in the alkaline regime, the so-called anomalous electrokinetic maximum. The maximum is removed giving a continuous decrease in zeta-potential when calculated with the theory of O＇Brien and White, which accounts for electrophoretic relaxation.