The trace of Cr in water was determined by spectrophotometry based on the catalysis of Cr (ⅵ) to the oxidation of xylidene blue by potassium bromate in acid medium .

研究了在酸性介质中铬（ Ⅳ）催化溴酸钾氧化 二甲苯 胺 蓝 褪色 的 最佳 条件。