工作场所空气中萘检测方法改进

Improvement of detection method for naphthalene in the air of workplace

目的 改进工作场所空气中萘的溶剂解吸-气相色谱法(国家标准方法)。方法 工作场所空气中的萘经硅胶采样管采集和以无水乙醇解吸(分别代替国家标准方法中的活性炭管和二硫化碳)后,采用气相色谱法测定。结果 方法改进后,萘在质量浓度为0.38~2 256.00 mg/L时线性关系良好,相关系数为0.999 99;检出限为0.05 mg/L,定量下限为0.17 mg/L;最低检出浓度为0.02 mg/m^(3),最低定量浓度为0.06 mg/m^(3)(以采集3.0 L空气计算);平均解吸效率为98.6%~103.0%,批内、批间相对标准偏差分别为0.5%~1.8%和0.4%~2.1%,样品在4℃冰箱内至少可保存14 d。结论 本方法快速准确,检出限低,解吸效率高,所用解吸液无水乙醇对实验人员和环境污染极小,在实际工作中有良好的应用。

Objective To improve the solvent desorption-gas chromatography method(national standard determination method) of naphthalene in the air of workplace. Methods Naphthalene in the air of the workplace was collected by silica gel tube and desorbed by absolute ethanol(instead of activated carbon tube and carbon disulfide in the national standard method, respectively), and determined by gas chromatography. Results After improvement of the method, the linear range of naphthalene was 0.38-2 256.00 mg/L. The correlation coefficient was 0.999 99, the limit of detection was 0.05 mg/L, and the lower limit of quantification was 0.17 mg/L. The minimum detectable concentration was 0.02 mg/m^(3), and the minimum quantification concentration was 0.06 mg/m^(3)(sample volume counted for 3.0 L). The average desorption efficiency of naphthalene was 98.6%-103.0%. The with-in run and between run relative standard deviations were 0.5%-1.8% and 0.4%-2.1%. The samples could be stored in the refrigerator at 4 ℃ for at least 14 days. Conclusion The method is fast and accurate, with low detection limit, high desorption efficiency, and the absolute ethanol used in the desorption liquid has little pollution to experimenters and the environment, and has good application in practical work.