Spectrophotometric determination of phytic acid in plant extracts using a multi-pumping flow system Original Research Article

A flow-based spectrophotometric determination of phytic acid (PA) in foodstuffs involving PA extraction and reaction with Fe(III)-salicylate is proposed. Extraction is accomplished in a parallel array of ion-exchange mini-columns and the extracts are introduced into an improved flow system with multi-pumping. About 150 samples are run per hour, meaning 1.3×10−2 μg FeCl3·6H2O and 7.7×10−3 μg sodium salicylate per determination. Baseline drift is usually <0.01 absorbance per hour and the analytical signals for 5–100 mg l−1 PA range from 0.45 to 0.04 absorbance. Linearity of the analytical curve is fair (r>0.999, n=5) and detection limit was estimated as 1.0 mg l−1 PA. Results are precise (R.S.D.<1%) and in agreement with HPLC.