Quadropole analyzer

Separate the formed ions according to their mass-to-charge ratio (m/z ratio). This takes place in the mass analyzer. By far, the most used analyzer is the quadropole, either as single or as triple quadropole, combined with a soft ioniza-... 

MALDI and ESI are capable of ionizing very large molecules with little or no fragmentation. The type of analyzer used with each can vary. MALDI sources are usually coupled to time-of-flight (TOE) analyzers, whilst ESI sources can be coupled to analyzers such as quadropole, ion-trap and hybrid quadropole time-of-flight (Q-TOF). 

Many catalyst complexes that are suitable for operation and immobilization in ionic liquids are ionic themselves with the charge either located at the metal center or in the ligand sphere. Thus, these complexes are accessible to electrospray ionization mass spectroscopy (ESI-MS). However, it is not a trivial task to investigate an ionic catalyst complex next to the vast excess of ionic liquid ions. Dyson s group reported a combination of ESI-MS with quadropole ion trap methods that enabled the detection of, e.g. several cationic Rh-complexes in the ionic liquid [BMIM][PF6] [62]. They could demonstrate that the detection limit of their methodology (catalyst concentrations down to 1 x 10 mol 1 were analyzed) is so low that even complexes in the typically very low concentration of a catalytic experiment could be easily characterized, even in the presence of a large excess of ionic liquid ions. 

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