VOCs气体的动态法配制及其浓度测定

Dynamic preparation of VOCs gas and determination of its concentration

选择丙酮为VOCs代表性污染物,借助PQMF-3B配气装置配制一定浓度范围的丙酮气体,分别采用气密针和六通阀两种方式进样,通过气相色谱对丙酮气体浓度进行测定。结果表明,气密针和六通阀进样法所得丙酮气体标准曲线的相关系数分别为99.98%和99.94%,线性相关性良好,丙酮气体的检出限为1.656 mg/m3,方法的相对标准偏差(RSD)为0.8%~2.3%(n=6)。研究得出,PQMF-3B装置用于VOCs气体配制,具有浓度稳定、操作简单、运行成本低的优势,“气密针进样+GC”和“六通阀进样+GC”两种方法均能实现VOCs准确测定。

Acetone was selected as the representative pollutant of VOCs,acetone gas in a certain concentration range were prepared by PQMF-3B distributing device.Acetone gas was injected by means of the air-tight needle and the six-way valve,respectively,and then was measured by gas chromatography.The results show that the correlation coefficients of acetone gas standard curves obtained by the two injection method of air-tight needle and six-way valve are 99.98%and 99.94%,respectively,the detection limit of acetone gas is 1.656 mg/m 3,the relative standard deviation(RSD)is 0.8%~2.3%(n=6).It can be concluded that the PQMF-3B distributing device for preparing VOCs gas has the advantages of stable concentration,simple operation and low operating cost.VOCs gas can be accurately determined by the two method of“air-tight needle injection+GC”and“six-way valve injection+GC”.