Study on Simultaneous Spectrophotometric determination of Zinc and Iron by Multivariable Calibration

It is reported in this paper that any of the Zn(Ⅱ) and Fe(Ⅲ) ions can react with xylenol orange(XO) at pH 5.98 HAc-NaAc buffer solution,and form stable colorful complexes.Their absorption maximum lie at 571 nm and 500 nm,and absorption spectra overlapped.The overlapped spectral data are treated by multivariate calibration of chemometrics approaches.The results show that the linear ranges of the calibration curves for zinc and iron are 0.5~4 μg·mL~(-1) and 0.2~1.8 μg·mL~(-1),The limits of detection for zinc and iron are both 0.13μg·mL~(-1).Some chemometric methods such as partial least squares algorithm are applied to the simultaneous spectrophotometric determination of zinc and iron in food samples with satisfactory results.