For decades, gas chromatography (GC) in combination with electron ionization (EI) mass spectrometry (MS) has been the method of choice for targeted and suspect screening analysis of volatile and semi-volatile compounds. The standard method of applying 70 eV electrons offers nonselective ionization with high efficiency and produces characteristic, reproducible compound fragmentation patterns. These allow for a straightforward database matching and provide valuable structural information to further confirm the molecules of interest. This has made EI the unmatched gold standard ionization for GC-MS analysis.
In nontarget analysis (NTA) and for high confidence compound identification however, instrumentational requirements are more elaborate due to the lack of information on the analytes prior to the analysis – in these cases molecular ion information is required. Unfortunately, the extensive fragmentation following the 70 eV EI process is often results in the loss of this required molecular ion information. For compound identification and NTA, especially when a compound confirmation via standard analysis is not available, the use of EI alone is not sufficient.
The TOFWERK ecTOF offers a unique solution to this type of complex analysis problem. The ecTOF provides robust GC-MS analysis using simultaneous electron and chemical ionization. TOFWERK’s extensive knowledge of chemical ionization opens the opportunity to a wide range of special CI sources and reagents, depending on the analysis needs. The ecTOF solution therefore offers parallel generation of molecular ion information via CI next to the structural information of conventional EI. Therefore, identification confidence is increased and non-targeted analysis methods using gas chromatography are greatly improved.
Key Discussion Points
- Introduction of the ecTOF technology
- ecTOF features and performance, including different chemical Ionization (CI) options
- Example applications with focus on compound identification
- Workflows and data post processing