Table 1 Mass Measurement Error. Standard deviation (SN) observed for the trytpic autolysis peaks 842.508 and 2211.1. Raw data; TPS – Thin-Plate Spline (TPS) calibrated data; TPS-MST – The data, which undergone Thin-Plate Spline (TPS)(pre-processing), followed by Maximum Spanning Tree (MST) calibration