硝基苯甲酸同分异构体分析及其在废水预处理中的应用

Analysis of Nitrobenzoic Acid Isomers and Its Application in Wastewater Pretreatment

间硝基苯甲酸生产及精制过程中会产生大量高浓度硝基苯甲酸同分异构体废水.为了选择和优化废水预处理的工艺条件,需要分离和检测样品中的各种硝基苯甲酸.本研究建立一种采用高效液相色谱分离检测硝基苯甲酸同分异构体的方法,使用XDB-C18色谱柱,以甲醇-乙酸溶液(pH=3.0)(体积比为35∶65)为流动相,紫外检测波长为267 nm,考察了流动相组成、体积比、pH值及流速等对硝基苯甲酸同分异构体分离度的影响.结果表明:邻、间、对硝基苯甲酸分别在12.14~194.0 mg/L、13.78~220.4 mg/L、6.450~103.2 mg/L范围内线性关系良好,相关性系数R 2均大于0.9995,相对标准偏差均小于1.04%.利用该方法能够为间硝基苯甲酸精制废水预处理过程提供分析.

The production and refining of m-nitrobenzoic acid will produce a large amount of wastewater with high concentration of nitrobenzoic acid isomers.In order to select and optimize the technological conditions for wastewater pretreatment,it is necessary to separate and detect various nitrobenzoic acids in samples.In this study,a method for the separation and detection of nitrobenzoic acid isomers by high performance liquid chromatography is established.XDB-C18 column is used,methanol-water(pH=3.0)(volume ratio 35∶65)is used as mobile phase,and the ultraviolet detection wavelength is 267 nm.Effects of composition and volume ratio,pH value and flow rate of mobile phase on the separation degree of nitrobenzoic acid isomers are investigated.The results show that the linear relationship among o-,m-,p-nitrobenzoic acid is good in the range of 12.14-194.0 mg/L,13.78-220.40 mg/L and 6.45-103.20 mg/L,respectively.The correlation coefficient R 2 is greater than 0.9995,and the relative standard deviation is less than 1.04%.The analytical method can be used to provide an analysis for the pretreatment of refined wastewater of m-nitrobenzoic acid.