The LockSpray dual electrospray ion source optimizes the co-introduction of analyte and lock mass compound directly into the ion source, providing authenticated exact mass measurement in MS and MS/MS modes to within 5 ppm RMS mass accuracy (3 ppm for Xevo QTof MS and 1 ppm for Xevo G2 Tof series, Xevo G2 QTof series and SYNAPT G2 series).
The increased specificity associated with exact mass measurement provides you with improved efficacy in compound or fragment identification in metabolite profiling and proteomics applications.
Traditionally, to obtain valid exact mass measurement, an internal reference or “lock mass” was used to correct for changes in environment or experimental conditions over the course of the analysis. This was achieved by “teeing in” a suitable reference compound to the main analyte flow. However, this approach often suffered from ionization suppression, potential mass interferences and solvent gradient effects.
The LockSpray source design overcomes these limitations.