顶空-溶剂解吸气相色谱法测定工作场所空气中乙酸

Determination of acetic acid in air in a workplace by headspace gas chromatography

目的建立工作场所空气中乙酸的顶空-溶剂解吸气相色谱法。方法用硅胶管采集样品,硫酸溶液解吸,硫酸乙醇溶液衍生,一定温度下衍生后顶空进样,经毛细管柱分离后,用FID检测器检测乙酸浓度。结果方法检出限为4.2μg/ml,定量下限为14.7μg/ml,最低定量浓度为1.6 mg/m³(以采集4.5 L空气样品计),平均解吸效率为95.0%,线性范围为14.7~1 680.0μg/ml,相关系数良好为0.999 1。结论本方法采用顶空-溶剂解吸气相色谱法,可有效降低方法的最低定量浓度,且该方法各测量参数符合要求,操作简便,适用于工作场所空气中乙酸的测定。

Objective To establish the method of headspace-solvent solution in chromatography to detective acetic acid in workplace.Methods Samples were collected by silica gel tube, desorbed by sulfuric acid solution, derivated by ethanol sulfate solution, and injected into headspace after derivatization at a certain temperature. After separating by capillary column, the concentration of acetic acid was detected by FID detector.Results The detection limit was 4.2 μ g/mL, and the lowest quantitative limit was 14.7 μ g/mL, The lowest quantitative concentration was 1.6 mg/m³(based on 4.5 L air sample), and the average desorption efficiency was 95.0%. The linear range was 14.7-1 680.0 μ g/ml, the correlation coefficient was 0.999 1. Conclusion The headspace-solvent desorption chromatography can be used in this method. The method has the lowest quantitative concentration of the method, the measurement parameters of the method meet the requirements, the operation is simple and convenient, and the method is suitable for the determination of acetic acid in the air in a workplace.