用甲基异丁酮(MIBK)从6～7N盐酸溶液中萃取Fe~(3+),随后用水反萃取,以水扬酸作指示剂,用EDTA滴定萃出Fe~(3+)。方法简便迅速,15分钟完成测定。操作: 用吸量管自电镀液中准确吸取10毫升,于容量瓶中稀释至500毫升。吸取25毫升上述溶液于烧杯中,加入盐酸5毫升和乙醇2毫升,缓缓加热,不断搅拌,直到沸腾开始。使铬酸还原呈绿色。流水冷却至室温, Fe (3+) was extracted from 6 ~ 7N hydrochloric acid solution with methyl isobutyl ketone (MIBK), followed by stripping with water and titration with EDTA with salicylic acid as an indicator. Method is simple and quick, 15 minutes to complete the determination. Operation: Pipette exactly 10 ml from the plating solution and dilute to 500 ml in a volumetric flask. Pipette 25 ml of the above solution in a beaker, add 5 ml of hydrochloric acid and 2 ml of ethanol, slowly heat, stirring constantly, until boiling begins. Chromic acid reduction to green. Water cooled to room temperature,