Thin layer resin phase spectrophotometric determination of trace Fe(III) in water sample

A method to determine Fe(III) in water sample by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(III) and 1,2-benzendiol is concentrated on the 717^# resin. and that Fe(III) can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×10⁴L · mol^-1 · cm^-1, which is 16 times higher than that of liquid phase spectrophotometry. and most coexisting ions do not influence the determination. The detection limit for Fe(III) is 1.47ug/L with the precision of 3.3% (n=6, 7ug/50mL Fe(III)). The calibration curve is linear in the range of 0~25ug/50mL. The preposed method was applied to the determination of Fe(III) in water sample with satisfactory results.