对TH_PKU-300B挥发性有机物快速在线监测系统的改进

针对现有TH_PKU-300B挥发性有机机物快速在线监测系统在测定含氧挥发性有机化合物(OVOCs)、含氮挥发性有机物(NVOCs)和高沸点挥发性有机物时存在灵敏度低、精密度差、线性响应较差、记忆效应明显等不足,根据其原理,对其GC-MS通道的部分气路进行改进。通过实验对比分析,证明改进后的仪器系统响应更加灵敏、线性拟合度更高、精密度及解析效率均显著提高,同时检出限也由改进前的体积分数0.1×10~(-9)~1.0×10~(-9)降低至0.02×10~(-9)~0.08×10~(-9),并解决了记忆效应问题。改进后的系统在OVOCs、NVOCs和高沸点挥发性有机物测定方面要优于原系统。

Improvement on the TH_PKU-300B Fast On-line Monitoring System for Volatile Organic Compounds

For the existing TH_PKU -300B fast on -line monitoring system for volatile organic compounds ,some deficiencies were present such as low sensitivity,poor precision,poor linear response and serious memory effect in the determination of oxygenated vol -atile organic compounds (OVOCs),nitrogenous volatile organic compounds (NVOCs) and high boiling point volatile organic com -pounds.According to its working principles,part of the gas path in the GC -MS system was improved.The experimental results showed that the modified instrument was advantageous in sensitivity ,linear fitting degree,precision and thermal desorption efficiency . The detection limit was lowered from 0.1 ×10-9 ~1.0 ×10 -9 to 0.02 ×10-9 ~0.08 ×10 -9 ,and the problem of memory effect was solved.The modified instrument is superior to the original instrument in the determination of OVOCs ,NVOCs and high boiling point volatile organic compounds.