What is CCS?

Conventional mass spectrometers separate components on the basis of m/z. The SYNAPT XS, Cyclic IMS, and Vion IMS QTof systems also allow separation of molecules according to their size, shape, and charge during ion mobility experiments. Thus, ion mobility offers an additional dimension of resolution, which provides increased peak capacity and selectivity of analysis. The inclusion of ion mobility in an analysis significantly increases the extent and confidence with which complex mixtures and molecules can be profiled and dramatically enhances sample definition.

Ion mobility enables the measurement of the rotationally-averaged collision cross-section (CCS) of an ion. CCS is an important distinguishing characteristic of an ion in the gas phase.  It is related to its chemical structure and three-dimensional conformation.  CCS is used as an additional molecular identifier to help confirm the identity of an ion or investigate its structure. Moreover, it can also be used to increase confidence in the quantitative measurement of known compounds, thus reducing interferences and improving signal to noise (S:N) ratios.

Unlike chromatographic retention times, which tend to shift with varying sample matrix, CCS measurements are unaffected by sample matrix and are consistent between instruments and across a broad range of chromatographic experimental conditions making CCS an ideal parameter on which to build libraries and databases.

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