Table 2. Predicted Concentrations from ATR-FTIR Spectra from Figure 5 Using a PLSR Model.

concentrations (mol/kg solvent)	nitrate	nitrite	carbonate	sulfate	borate
Figure 5a predicted	0.863	0.711	0.517	0.025	0.305
Figure 5a gravimetric	0.883	0.719	0.538	0.026	0.304
Figure 5b predicted	0.877	0.827	0.560	0.073	0.862
Figure 5b gravimetric	0.879	0.818	0.522	0.078	0.852