Research Of Quality Control Methods Of Sampling And Analyzing Greenhouse Gases In China

It is crucial to use a complete and feasible quality control method and procedure in researching observation of concentration variety of background greenhouse gases and its factors.From the method of flask sampling and atmospheric sample storage, flask treatment process in laboratory,concentration of and CO₂ carbon and oxygen isotope analysis,observation of fluxes of greenhouse gases three aspects as well as generally analysis and research of the full-flow quality control measures and methods,this study eventually basically formed a systemic quality control procedures and methods.First of all,the experimental programs were designed and researched.Home-made auto-sampler and flasks,constant temperature oven and high vacuum flask cleaning system were tested.According to the test conditions and the corresponding results,further optimization of processes and methods was done.Through various laboratory tests,plourel O ring-glass spool rigid glass flasks can be made to significantly minimize the material quality of sampling bottle to the impact of gas storage.Before the fist storage of the new flask, vacuumizing and thermal desorption of inner surface of flasks in 60℃,72h can remove the water vapor adsorption not volatile at room temperature,as well as impurities as much as possible to ensure that storage gas is not contaminated;Secondly,when the analysis of atmospheric samples was finished,sampling flask vacuumizing-storage for 24 hours-the vacuum check of the flasks was needed.On the vacuum conditions of the high vacuum flask cleaning system,filling the checked flasks with balance gas(CO₂ concentration was significantly lower than that of the concentration of natural atmosphere),then the flasks were sent to sampling stations.These measures were carried out to monitor whether the dual-parallel flasks were completely washed with well mixed local atmosphere before sampling;Thirdly,according to the analysis accuracy of background greenhouse gases,a variety of experimental procedures were designed as well as joint testing and debugging were carried out,finaliy optimized conditions and procedures were selected.CO₂ stable isotope laboratory analysis system including commercial MAT253 host system and Gasbench injection system, home-made 16-bit auto-injection system,foreign R & D airtrap efficient pre-concentration trapping gases trap)was debugged to meet the analysis requirements.The final accuracy of carbon and oxygen isotope ratio analysis were 0.02‰,0.05‰; Finally,the air bags storing samples frequently-used in flux observation were detected and deled,including the structural analysis of airbags,airbag storage experiments.Strict standard working gases were used to interspersing during analysis process of the sample.In accordance with the testing results,some adjustments were applied in the sampling and transportation to minimize pollution of the samples.Rigorous analysis-quality controlcalibration procedures and methods that were consistent with that of analyzing and correcting the concentration of atmospheric background greenhouse gases were formed to ensure the data obtained using the two different observing methods could be accuracy compared.Then the relationship of the values mutually used between two systems-observation system of background greenhouse gases and that of greenhouse gases was established.On this basis, high-quality observing data of fluxes of CO₂,CH₄ in Mt.Waliguan were obtained.