Abstract
A simple, rapid and sensitive kinetic spectrophotometric method for the determination of trace amounts of iron (II) was developed based on its catalytic effect on the oxidation of variamine blue with hydrogen peroxide in the presence of triethanolamine as activator to form a deep violet blue colored species with an absorption maximum at 560 nm. The reaction was monitored using FIA and batch methods. The calibration graphs were linear in the concentration range 5.4-130 and 3.4-40 ng of iron for the FIA and batch, respectively. The FIA technique showed good average recoveries with lower detection limit compared with the batch technique. The method was highly selective to iron (the tolerance limit for 20 ions was listed) and successfully applied for iron determination in pharmaceutical preparation, polluted air and tap water with average recoveries agreed with the official method.
