Improved Spectrophotometric Determination of Total Iron and Iron(III) with <i>o</i>-Hydroxyhydroquinonephthalein and Their Characterization

Simultaneous and fractional determination of iron(II) and iron(III) was accomplished with o-hydroxyhydroquinonephthalein (QP) in the presence of poly (N-vinyl pyrrolidone). In the determination of total iron (iron(II)+iron(III)), Beer's law was obeyed in the range of 0.02-0.67 μg·ml−1, with an effective molar absorptivity (at 570 nm) and a relative standard deviation of 1.30×105·l·mol−1·cm−1 and 0.77% (n = 8), respectively. This method was about...