🧲 NMR Residual Solvent Peak Reference
Look up ¹H and ¹³C residual solvent peaks, plus the residual water peak, for common deuterated NMR solvents.
Frequently asked questions
Why do I need to know the residual solvent peak?
Deuterated NMR solvents are never 100% isotopically pure, so a small residual proton (and corresponding carbon) signal from incompletely deuterated solvent molecules always appears in the spectrum. Recognizing these peaks prevents misidentifying them as sample impurities or, worse, as sample signals.
Why does the residual solvent peak show a multiplet pattern (e.g. quintet, septet)?
The residual protium is coupled to the surrounding deuterium atoms in the partially deuterated solvent molecule. Since deuterium has spin 1, coupling to multiple deuteriums produces the characteristic multiplet patterns seen (e.g. DMSO-d6's residual CD2H proton couples to 2 deuteriums, giving a 1:2:3:2:1 quintet).
Why is the water peak shift so variable?
The chemical shift of residual water is highly sensitive to hydrogen bonding, which changes with concentration, temperature, and trace acid or base contamination in the sample or solvent. This is why water peak shifts are reported as approximate ranges rather than fixed values, unlike the much more stable solvent residual peaks.
Accuracy & how this is derived
Derivation: Direct reference lookup — no calculation is performed. Values are taken from the standard published table of residual solvent signals.
Validated against: Gottlieb, H. E.; Kelly, V.; Nudelman, A. J. Org. Chem. 1997, 62, 7512 — the standard reference for NMR chemical shifts of common laboratory solvents as trace impurities.
⚠️ For educational and research support only — verify critical results independently before use in regulated, clinical, or publication-bound work.
✔ Last updated: July 2026 · Report an error
Identifying residual solvent peaks in NMR spectra
Every deuterated NMR solvent contains a small fraction of incompletely deuterated molecules, producing a characteristic residual proton signal — and a corresponding carbon signal in 13C spectra — at a well-established chemical shift for each solvent. Recognizing these residual peaks, along with the separate and more variable residual water peak that appears in most solvents, is a basic but essential skill for correctly interpreting NMR spectra and avoiding the common mistake of mistaking a solvent artifact for a genuine sample signal or impurity.