Takaoka T, Taya T, Otomo M
Department of Applied Chemistry, Nagoya Institute of Technology, Gokiso, Showa, Nagoya 466, Japan.
Talanta. 1992 Jan;39(1):77-80. doi: 10.1016/0039-9140(92)80054-h.
The optimum conditions for the extractive-spectrophotometric determination of trace iron(II) with di-2-pyridylmethanone 2-(5-nitro)pyridylhydrazone have been established. Iron(II) reacts with this reagent at pH 2.0-7.5 to form an uncharged 1:2 (metal-to-ligand) complex, which can be extracted with toluene. Beer's law is obeyed over the range up to 0.84 mug/ml of iron(II) at 505 nm. The molar absorptivity of the extracted species is 5.83 x 10(4) 1.mole(-1).cm(-1). The proposed method is extremely sensitive and reproducible, and has been satisfactorily applied to the determination of total iron in freshwater samples by adding ascorbic acid to reduce iron(III).
已确定用二 - 2 - 吡啶甲酮2 - (5 - 硝基)吡啶腙萃取分光光度法测定痕量铁(II)的最佳条件。铁(II)在pH 2.0 - 7.5时与该试剂反应形成不带电荷的1:2（金属与配体）络合物，该络合物可用甲苯萃取。在505 nm处，铁(II)浓度高达0.84 μg/ml范围内符合比尔定律。萃取物的摩尔吸光系数为5.83×10⁴ l·mol⁻¹·cm⁻¹。所提出的方法极其灵敏且可重现，通过加入抗坏血酸还原铁(III)，已成功应用于淡水样品中总铁的测定。
