Application of a periodate liquid membrane electrode to the determination of α-diols, carbohydrates and hydrazines

Abstract

A liquid membrane electrode that is sensitive and reasonably selective for the periodate ion is described. It incorporates a nitrobenzene solution of nitron-periodate as an ion-exchange site. The electrode displays a near-Nernstian response for 10^–2–10^–5M periodate with an anionic slope of 55 mV (concentration decade)^–1. The potential response is fast (<1 min) and almost independent of pH over the range 3–7. Selectivity coefficient data for 30 inorganic and organic anions show negligible interferences from most common anions. The electrode has been used satisfactorily for the direct determination of 0.01–2.5 mg ml^–1 of periodate with an average recovery of 98.9% and a mean standard deviation of 1.4%. Some α-diols, reducing carbohydrates and hydrazines at concentrations of 0.05–2.5 mg ml^–1 were determined by reaction with periodate under controlled conditions followed by measurement of the excess of the reagent. An average recovery of 98.2% and a mean standard deviation of 1.7% were obtained.