Mass Spectrometry for On-Line Monitoring of Perfluoro Compounds Using Li+ Ion Attachment Techniques

Ion attachment mass spectrometry is being developed for continuous measurement of perfluoro compounds (PFCs) found in the atmosphere as a result of semiconductor manufacturing processes. Studies were made on 5 greenhouse gases, CF4, CHF3, C2F6, SF6, and c-C4F8, to develop improved methods for PFC analysis, particularly at levels found in the atmosphere (the parts-per-billion concentration range). The results demonstrate the feasibility of performing real-time measurements of the trace amounts of PFCs encountered in process facilities by generating adduct ions from Li+ ion attachment. The identification and detection of c-C4F8 is described as an example of the utility of this new method.