北京市大气甲醛浓度研究

Determination of Atmospheric Formaldehyde in Beijing by High-Performance Liquid Chromatography

分别于2006年7,9,12月和2007年3月采用2,4-二硝基苯肼(DNPH)高效液相色谱法测定了北京市大气中的φ(甲醛).结果表明:在观测期间,春、夏、秋、冬各季φ(甲醛)的平均值分别为7.56×10-9,12.70×10-9和7.24×10-9,3.34×10-9;夏季φ(甲醛)明显高于其他3个季节,春、秋φ(甲醛)平均值非常接近,冬季φ(甲醛)最低;夏季φ(甲醛)与φ(O3),温度,UVB的日变化表现出良好的一致性,均在12:00—15:00出现高值;夏季φ(甲醛)主要受光化学氧化过程的控制和影响;降水对大气甲醛有明显的清除作用.

The level of formaldehyde in Beijing ambient air was measured by 2, 4-dinitrephenylhydrazine （DNPH） and HPLC. This method was applied to monitor formaldehyde concentrations of Beijing ambient air in July, September, December 2006 and in March 2007. During the study period, the average level of formaldehyde was 7.56 × 10^-9 , 12.70 × 10^-9 , 7.24 × 10^-9 and 3.34 × 10^-9 for spring, summer, autumn and winter respectively. The level of formaldehyde in summer was obviously higher than that in the other three seasons, the spring level was near to the autumn level, and the winter level was lowest. During summer, HCHO, O3, UVB and temperature showed a similar diurnal variation, and their peaks all appeared during 12：00 to 15：00. This phenomenon provided direct evidence that the formaldehyde levels were significantly affected by the atmospheric photo-oxidation processes in summer. The wet deposition played an important role in removal of atmospheric formaldehyde.