A simple capillary electrophoretic method is described for the simultaneous determination of soluble oxalate and nitrate in forage grasses. Grass samples were ground and extracted with water. The extracts were filtered and submitted to capillary electrophoresis. Electrophoresis was performed in a 75 μm ×50 cm fused silica capillary with 30 mM sodium sulfate containing an electroosmotic flow modifier under constant voltage at —8 kV Separated oxalate and nitrate were detected with direct UV absorption at 214 nm. The present method can be used for routine monitoring of the concentration of soluble oxalate and nitrate in grasses.
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