室内空气中VOC全采样多项快速检测技术研究

Study on the technique for quick determination and whole sampling of VOC in indoor air

采用硅烷化处理内壁的不锈钢采样罐采集室内空气样品,三级冷阱预浓缩,气相色谱-质谱仪联用分析室内空气中挥发性有机物(VOC)。选取100、50、25、10、52、ppb浓度点VOC标准气体绘制标准曲线,曲线的线性相关系数R≥0.99,每个浓度点重复测定的相对标准偏差RSD<5%(n=6),平均相对标准偏差MRSD<5%(n=6)。现场采样分析结果,平行样测定结果之差与平均值比较的相对偏差<10%。本检测方法的扩展不确定度10.6%。方法可实现对现场挥发性有机气体的全采样、全分析,避免了因吸附剂的选择吸附性所引起的采样、分析误差。

We sample from indoor air using silonite coated canisters, preconcentrate low level samples utilizing three stages focuser, analyze VOC in indoor air with GC/MS equipment.The standard VOC gas in our study has 39 components. We draw calibration curve with VOC concentrations of around 100,50, 25, 10, 5,2 ppb. The correlation coefficient of the curve is greater than 0.99, the Relative Standard Deviation is below 5% （n = 6）, and the Medium Relative Standard Deviation is below 5% （n = 6） .According to the results of sampling and analyzing of indoor air, the relative error of parallel samples is below 10% .The Extended Uncertainty of this method is 6% .Using this method we realize the whole sampling and analyzing of VOC, avoiding the error coming from the selective adsorption of the sorbent.