[On-line analysis and mass concentration characters of the alkali metal ions of PM10 in Beijing].

The mass concentration characters and the sources of water-soluble alkali metal ions in PM10 in 2004 and 2005 in Beijing were analyzed by using the system of rapid collection of particles. The result showed that the average concentration of Na+, K+, Mg2+ and Ca2+ was 0.5-1.

[Water-soluble chloride in aerosol PM10 in Beijing].

Water-soluble chloride is one of the most important components in aerosols. The chloride in PM10 measured from January to December 2004 in Beijing was determined using a system by combing rapid collection of fine particles and ion chromatography (RCFP-IC). The results showed that the annual average concentration of water-soluble chloride at the urban area in Beijing was about (3.

An improved gas chromatography for rapid measurement of CO2, CH4 and N2O.

Combining improved injector, gas line and valve-driving modules, a GC equipped with FID and ECD, could simultaneously measure CH4, CO2 and N2O in an air sample within 4 min. Test results showed that the system has high sensitivity, resolution and precision; the linear response range of the system meets the requirement of in situ flux measurements. Thus, the system is suitable for monitoring fluxes of main greenhouse gases in terrestrial ecosystem since it is easy to use, efficacious, stable and reliable to collect data.

[Trends and variation of CFC-11 in the atmosphere of Beijing].

In recent years, concentration of CFC in the atmosphere has undergone rapid changes especially in association with human activities. For the influence of CFC on climate changes and environment changes, the concentration of atmospheric CFC-11 in Beijing is continuously observed and analyzed by a gas chromatography-mass spectrometry. The seasonal variation concentration and trends of CFC-11 are reported.

[Measurement and study on the atmospheric trace BTEX in Beijing].

Atmospheric trace BTEX in Beijing was observed by a gas chromatography/mass spectrometry in the latest 4 years. The diurnal, lunar and annual concentration variations of these pollutants were reported. In winter and spring, the diurnal profiles exhibited two peak values corresponding to the daily rush hours 08:00-10:00 am and 17:00 pm; in autumn, there was the third peak value in the night at 22:00; the highest concentration of BTEX in summer appeared in the midday and totally three daily maxima were in the sampled day.