分光光度法测定冷却水中铁离子的含量

实验采用邻菲罗啉分光光度法测定常减压蒸馏装置冷却水中铁离子的含量，从而评价腐蚀抑制剂的缓蚀效果。实验结果表明，当在蒸馏装置中加入缓蚀剂后，常压塔塔顶冷却水中铁离子含量由55．797mg／L下降至0．907mg／L，蒸发塔塔顶冷却水中铁离子的含量由80．559mg／L下降至1．996mg／L，缓蚀剂的加入减缓了装置的腐蚀。冷却水中的铁多以Fe3＋形式存在，Fe3＋经盐酸羟胺还原为Fe2＋后，可与邻二氮菲反应生成橙红色络合物，即可用分光光度计测定。与实验室常用的金属挂片腐蚀法相比较，该方法不仅可以用于实验室，而且可用于现场腐蚀监测。

Determination of Iron Ions in Cooling Water by Spectrophotometry

The concentration of iron ions in the distillation unit cooling water was determined by spectrophotometry with 1,10 - phinanthroline in order to evaluate the effect of corrosion inhibi- tom. The content of iron ions in cooling water of atmospheric tower decreased from 55. 797 mg/L to 0. 907 mg/L after the corrosion inhibitor is added in distillation apparatus. The iron in the cooling water exists in the form of Fe3＋ with hydroxylamine hydrochloride to Fe2＋ , Fe2＋ and 1,10 -phinan- throline can formed a colored compound which can be investigated by spectrophotometry. Comparing with the commonly used method of weight loss, this method could be used both in laboratory and for monitoring corrosion on site.