Use of photochemical reactions in flow injection: determination of oxalate in urine

Abstract

The use of photochemical reactions in flow injection (FI) is reported. The irradiation of an FI reactor with a suitable source facilitates the development of the iron(III)-oxalate reaction, allowing the amperometric determination of the anion in the range 1.0–13.0 µg ml^–1, with a relative standard deviation of 1.1% and a sampling frequency of 40 h^–1. The proposed method was applied successfully to the determination of oxalate in urine samples.