Simultaneous kinetic spectrophotometric determination of periodate and iodate based on their reaction with pyrogallol red in acidic media by chemometrics methods

The univariate and multivariate calibration methods were applied for the simultaneous determination of iodate and periodate in water. The method is based on the reaction of periodate and iodate with pyrogallol red in sulfuric acid media. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of pyrogallol red at 470 nm. The calibration curve was linear over the concentration ranges of 0.1–12 and 0.1–14 (mu)g ml^-1 for iodate and periodate, respectively. The experimental calibration matrix for partial least squares (PLS) and orthogonal signal correction (OSC–PLS) method was designed with 35 mixtures. The results obtained by the PLS and OSC–PLS were statistically compared. The effects of various cations and anions on iodate and periodate determination have been investigated.