Comparison of solvent suppression pulse sequences for bupivacaine HCl D2O/H2O 10%/90% (v/v). Standard 1 H NMR spectrum (A) is shown for comparison. Peaks highlighted in green, or purple are proximate to the water peak and are used to indicate non-selective suppression. TSE-PSYCHE-ES 1 H NMR (B) suppressed most of the HOD peak, albeit with significant baseline distortions and suppression of nearby signals. Pure shift 1 H NMR spectral quality was improved significantly with 1D NOE-PSYCHE (C) and SAPPHIRE-iES solvent suppression (D) experiments, though residual solvent signal and slight baseline distortions were still observed. Applying the SAPPHIRE-iW5 pulse sequence (E) led to near-complete solvent suppression and maximum intensity of analyte peaks neighboring the residual solvent peak. Non-SAPPHIRE experiments were acquired with four times more scans than SAPPHIRE experiments to keep experiments comparable. The average signal-tonoise ratio per time unit in (E) is about 2.6 times larger than (C) due to the reduction in recycle delay and a slight increase in signal-to-noise ratio due to smaller loss by relaxation. The average signal-to-noise ratio per time unit in (D) is about 1.4 times larger than (C) due to the reduction in recycle delay and a small decrease in signalto-noise ratio due to more significant loss by relaxation and diffusion. All spectra were adjusted for comparable intensities. Experimental duration (in minutes and seconds) is shown along with their respective spectra.