顶空气相色谱法检测乙酸钠碳源含量

Detection of Sodium Acetate Carbon Source Content by Headspace Gas Chromatography

硝态氮(NO_(3)^(-))作为最常见的水污染物之一,已经在世界许多地方造成了严重的水污染问题。有机碳源的存在是厌氧反硝化作用的必要条件。乙酸钠碳源在污水处理中作为外加碳源使用十分普遍。目前乙酸钠碳源含量的检测手段只有化学滴定法、分光光度法和COD Cr法等,这些方法操作繁琐,干扰因素较多。本研究开发了一种基于顶空气相色谱的检测方法,样品用磷酸酸化后生成乙酸,经顶空气相测定。结果表明,乙酸钠在10~250 mg/L质量浓度范围内线性关系良好,相关系数为0.99991,样品的加标回收率在91.8%~102.3%,相对标准偏差小于5%。该方法准确、简便、快速,可大幅度提高工作效率,适合在各级环保实验室推广。

Nitrate nitrogen(NO_(3)^(-))as one of the most common water pollutants,has caused serious water pollution problems in many parts of the world.The presence of organic carbon sources is a necessary condition for anaerobic denitrification.Sodium acetate as a carbon source is widely used in wastewater treatment.Currently,the detection methods for the content of sodium acetate carbon source only include chemical titration,spectrophotometry,and COD Cr method,which are cumbersome to operate and have many interfering factors.This study developed a detection method based on headspace gas chromatography,in which the sample is acidified with phosphoric acid to generate acetic acid for headspace measurement.The results showed that the linear relationship of sodium acetate in the concentration range of 10~250 mg/L was excellent,with a correlation coefficient of 0.99991.The spiked recovery of the samples was between 91.8%and 102.3%,and the relative standard deviation was less than 5%.This method is accurate,simple,and fast,greatly improving work efficiency,and is suitable for promotion in environmental laboratories at all levels.