Continuous flow analysis of iron in zinc electrowinning electrolyte using an iron chalcogenide glass ion-selective electrode

摘要

It is shown that the iron(III)chalcogenide glass membrane ion-selective (ISE)can be calibrated in continuous flow analysis (CFA)using acidified iron(III)nitrate standards,yielding a 60+-3 mV per decade change in activity of Fe(3+) response in the range 10~(-7)-10~(-2)M tatal iron(III).Extended ageing of the iron(III)ISE in 2M zinc(II)sulphate did not alter the potentiometric response characteristics of the electrode.Furthermore,electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy inthe presence and absence of zinc(II)sulphate failed to detect a zinc(II)interference on the iron (III) yieded results falling within +-0.2log a Fe~(3+) unit of the corresponding iron speciation data calculated using the MINTEQA2 program.