离子色谱法测定焦化废水中的Cl^-、NO_3^-、SO_4^(2-)、S_2O_3^(2-)和SCN^-

Determination of inorganic anions in coking wastewater samples by ion chromatography

研究了用离子色谱法同时测定焦化废水中的Cl-、NO3-、SO24-、S2O23-和SCN-的含量。以Na2CO3-NaHCO3为流动相,乙腈为有机改进剂,自动进样器进样,待测离子经Metrosep A SUPP 5阴离子交换柱分离,抑制电导检测。实验优化了流动相组分的配比、有机改进剂的种类和浓度以及淋洗速度对分离效果的影响。在优化实验条件下,该方法线性相关性好(R>0.998 9),灵敏度高,检出限在0.06～0.28 mg/L范围内,精密度好(RSD<3.1%)。将该方法应用于焦化废水中无机阴离子的测定,并进行加标回收试验,回收率在89.4%～104.7%之间,结果令人满意。该方法操作简单、速度快、选择性好、准确度高,适合大批量工业废水中多种阴离子成分的同时测定。

In this paper, the contents of CI^- , NO3^- , SO4^2- , S2O3^2- and SCN^- in coking wastewater samples were deter-mined simultaneously by ion chromatography. Separation of five anions was achieved on a high capacity A-SUPP-5 column with mobile phase of Na2CO3-NaHC03 and organic modifier of 15% acetonitrile. The detection was performed by a sup- pressed eonductivity detector ,with 20 μL sample loop for au-tomatic injection. The constitutes of mobile phase, the types and concentrations of organic modifier and washing velocity were optimized. Under certain experimental conditions, there exists linear correlation between the contents of various anions and peak areas （ R 〉 0. 998 9 ） , with a detection limit in the range of 0. 06 ~ 0. 28 mg/L and relative standard deviation （RSD） less than 3.1%. Recovery results were between 89.4% - 104.7% ,which indicating the feasibility of the pro- posed method for inorganic anions monitoring in coking wastewater samples.