HRMS on Demand - The Role of Accurate Mass Measurement in Scientific Publications

Noam Tal, Chemistry, Tel-Aviv Univ, Tel Aviv, Israel

HRMS is considered by many users, mostly organic chemists, as being the ultimate method for sample confirmation and identification. A vast number of journals demand HRMS analysis for every reported new compound. This attitude led to the formation of a wide spread misconception about the resolution of an MS system as being the most important factor. HRMS provides elemental composition analysis based on a single peak with mass accuracy that alters over the mass range and is often dependent on the ionization method. Structure confirmation is its main advantage because the compound is not an "unknown", on the contrary, its structure is elucidated usually from NMR or organic reaction mechanism study and is known to some extent. Therefore, the HRMS elemental composition analysis is used in order to confirm or reject an expected structure based on other analytical tools rather than searching all possible elemental formula within a certain range. Examples of HRMS Elemental composition report of some complex compounds will be presented and discussed.