Aqueous extraction of copper and iron from palm oil by ultrasonic cavitation

Abstract

A method for the extraction of Cu and Fe from palm oil into an aqueous solution using a 20 kHz ultrasonic probe is described. The acidic aqueous phase was separated from the organic phase through a filter-paper after agitation. The optimum conditions for the extraction were a power of 200 W and an agitation time of 4 min with 1.00 mol dm^–3 HNO₃. A recovery of approximately 98% of 4 ppm Cu and Fe from the spiked samples was achieved with a precision of less than 2% relative standard deviation (RSD). The proposed method was compared with standard dry ashing sample preparation and precisions of not more than 5 and 37% RSD for the proposed and standard methods, respectively, were attained. A sample preparation time of less than 10 min is possible, and the prepared sample may be readily aspirated into the atomizer of an atomic absorption spectrometer.