Analysis Ethylene Oxide by EPA 327 Using Preconcentration Technology

Ethylene Oxide is a toxic compound existing in ambient air. It is existing in a very lower level as low as ppt in concentration. USEPA developed a method EPA 327 and this method is given a guideline for QA/QC from sampling, analysis and reports etc. The authors developed a method by using preconcentration technology with a GCMS system to handle the ambient air samples. The three stages LN2 based cryogenic trap and focuser system is adopted. The GCMS with both SIM and full scan technology also used for very low-level testing. The sampling train is a digital controlled MFC with timer and pressure sensor and the sample container is a silica coated canister. The QA/QC control factors are all followed EPA Method 327 and all achieved. This presentation gives the major technology set up and the testing methodologies. The results show that the linear of calibration, the continue calibration verification, the secondary source standard verification, the blanks for canisters and sampling train as well as system and the MDL study are all achieved the requirement by the method. This technology also give a shorter run time to make the laboratory more productive.