溴酸钾—甲基红催化分光光度法测定水体中亚硝酸盐的研究

Determination of Nitrite by Spectrophotometry Based on Potassium Bromate-Methylene Red Catalysis

摘要:

对水中亚硝酸盐的测定方法——溴酸钾—甲基红催化分光光度法进行了研究。通过单因素实验和正交实验,得出测定的最佳条件为:向两只比色管中分别加入4.0 ml H3PO4、2.6 ml甲基红、4.5ml KBrO3溶液,向其中一只加入2ml的NO2-标准液,然后均置于80 ℃水浴中加热15min。取出后用流水冷却至室温,在波长518 nm处用1 cm的比色皿,以水作参比,分别测量吸光度。该法的测定范围为:0.2～20 μg/ml。

Abstract:

The method determinating nitrite by spectrophotometry based on potassium bromate-methylene red catalysis was studied in this paper. With single factor experiments and orthogonal experiment, the optimum conditions were determined as follows: 2.6 ml methyl red solution, 4ml phosphate acid (1.5%) and 4ml potassium bromate solution were added into two colorimetric tubes. In one of the tube 2ml nitrite solution was added. Two tubes ware all heated at 80℃ for 15 minutes, then cooled to room temperature. At last, the percent absorption were determined at 518nm with water as the reference solution. The linear range of the result is 0.2 to 20μg/ml.