Chemiluminescent determination of oxalate based on its enhancing effect on the oxidation of methyl red by dichromate

A flow injection configuration for the chemiluminescence determination of oxalate is proposed. The procedure is based on the catalytic effect of oxalate on the oxidation of methyl red by dichromate. The chromium(III) formed catalyzes the luminescent reaction between luminol and hydrogen peroxide. The proposed method is simple, inexpensive, sensitive and suitable for concentrations of oxalate between 0.24 and 8.11 μg ml−1. The applicability of the method was demonstrated by determining oxalate in vegetables.