Figure 1

Method development on a DESI 7 T LTQ FT mass spectrometer. (a) Plot showing the measured 4-peak average mass error and (b) the base peak signal-to-noise ratio (SNR) with varying ion accumulation time. Data collected via subsequent line scans across a rat brain tissue section. Values shown are calculated from the averaged mass spectrum via Thermo Xcalibur Qual Browser with SNR calculated on the base peak and mass error calculated as the average error for four highly abundant lipid species (details in Supplementary Table S1).