Figure 2.

Evaluation of selected target compounds containing 2–7 labile hydrogens (#H Bond Donors) under (a) conventional HILIC-MS with post-column addition of D₂O (50 µL/min); (b) conventional HILIC-MS with post-column addition of D₂O (100 µL/min); (c) partial HILIC-HDX-MS with D₂O used in the mobile phases; (d) full HILIC-HDX-MS with D₂O, D₅-ammonium formate, D₂-formic acid used in the mobile phases. Full H/D exchange is indicated with a solid box (□). The most abundant ion (base peak) in the MS1 spectrum is labeled blue ($■$), and the color of lower intensities is proportionally scaled. For details of the composition of mobile phases and used modifiers, see Table 1.