非甲烷总烃监测分析研究

Key Factors for Determining Non-methane Hydrocarbons

2015年《中国环境状况公报》显示,大部分城市臭氧作为首要污染物的天数有增加趋势。而大气中的VOCs是产生臭氧最重要的前体物,同时也能对PM_(2.5)产生影响,成为监测和控制的重点,被纳入总量控制体系。上海、广州、西安等地方已采用非甲烷总烃作为VOCs的评价指标。结合环境监测分析工作的实际情况,探讨了非甲烷总烃的样品采集、进样方式、样品色谱柱,结果表明:与注射器采样相比,气袋气密性和化学惰性好,保存样品时间长;采用一次进样,双色谱柱GDX502/104、玻璃微球同时分离样品,双FID同时检测,节约时间,避免误差,更加快速、准确。

According to China Environmental Status Bulletin 2015, in the most cities, there is an increasing trend in the number of days that Ozone was the primary pollutant. Volatile organic compounds（VOCs） is one of the most important precursors to produce ozone, at the same time also can have an impact on PM2.5. VOCs planning into the total quantity control system is become the focus of monitoring and control. Because non - methane hydrocarbons （NMHC） represents the degree of volatile organic pollution in the air, some cities such as Shanghai, Guangzhou and Xi＇an have used NMHC as the evaluation index of the VOCs. For supplying some suggestion for the actual work, we discussed and analyzed the sample collection, injection mode and the chromatographic colunm. The results showed that the sampling bag have good air tightness and chemically inert and conserve sample longer. The mothed to analyze NMHC by gas chromatography with couple columns and couple FID detector is faster and more ccurate.