Figure 8: (A) Modified standard additions plot for Cysteine3TMS (target ion 220.2 Th; data from the main basic experi-ment in Figure 1). The broken line is drawn through the experimental points at added concentrations of 0 μM and 50 μM and is forced to intercept the abscissa -50 μM. (B) Modified standard additions plot for Cysteine3TMS (data from the MW basic experiment). Reaction mixtures were injected twice, respectively, in direct order from Vial0 to Vial4 (solid line) and in reverse order (broken line).