光度法测量电镀废液中的微量Cr(Ⅵ)

Determination of Trace Cr(Ⅵ) in Electrodepoist Waste Water Photo Metric Method

在稀硫酸介质中 ,Cr(Ⅵ ) 5 -溴水扬基酮 (5 -BrSAF)氧化成最大吸收率为 4 94nm的有色产物 ,其表观摩尔吸光系数ε494为 3 76× 10 4。Cr(Ⅵ )在 0～ 17μg/ 2 5mL范围内服从比耳定律 ,用此法测定电镀废液中的Cr(Ⅵ ) ,回收率为 98 7%～ 10 1% ,相对标准偏差为 2 4 %

The 5-Bromo-salicyl-fluorone(5-BrSAF) is oxidated by Cr(Ⅵ) in the medium of sulfuric acid and the maxiamum absorption of the coloure compound is 494 nm,It's apparent molar photo-absorptivity is 3 71×10 4.The amount of Cr(Ⅵ) in the range of 0～17μg/25mL is obeyed to Beer's law.This method is used to determine the trace Cr(Ⅵ) in electrodepoist waste water,the recovery is 98 7%～101% and relative standard deviation is 2 4