A method for periodate determination was developed as a result of static and flow-injection voltammetric investigations where a rotating platinum wire electrode was employed. In the static system, 4.0 X 10(-5)-4.2 x 10(-4) M periodate could be determined in the cell in pH 7.0-7.5 phosphate buffer. In the flow-injection system, periodate solutions of 20-100 mu l were injected into the carrier stream of a phosphate buffer solution at pH 7.0. The flow rates were in the range of 1.0-1.7 ml min(-1). The peak currents were measured at -0.07 V against a saturated calomel electrode. The determination of periodate concentrations in the range 1.0 X 10(-5)-1.0 X 10(-4) M was possible with a throughput of 15-40 samples per hour.