Determination of iron(III) in water samples by microsequential injection solid phase spectrometry using an hexadentate 3-hydroxy-4-pyridinone chelator as reagent.

In this work, the hexadentate 3,4-hydroxypyridinone ligand was used as reagent for the spectrophotometric quantification of iron(III) in fresh and sea waters, using a micro sequential injection lab-on-valve (µSI-LOV) system in a solid phase spectrometry (SPS) mode. To implement SPS, thus eliminating the sample matrix, a packed column in the flow cell was used; the chosen sorbent was Nitrilotriacetic Acid Superflow resin (NTA). The possibility of performing an analytical curve resorting to just one standard was also demonstrated. The consumption of the hexadentante ligand was about 30 µg per determination and the effluent production lower than 2.5 mL. The dynamic concentration range was 0.45-9.0 µmol L, with a limit of detection of 0.13 µmol L and limit of quantification 0.43 µmol L. The proposed µSI-LOV-SPS methodology was successfully applied to river, ground, estuarine, tap, and sea waters.