
Free
About
Is there a peak in your NMR spectrum you cannot assign? NMR Solvent Impurities is a fully offline reference for quickly identifying the residual signals of deuterated solvents and the trace impurities commonly met in the lab.
PEAK SEARCH
• Single peak: choose the solvent, the chemical shift (ppm, ± tolerance) and the splitting (singlet, doublet, triplet, quartet, multiplet…). Exact matches come first, compatible splittings next; incompatible ones are left out.
• Multiple peaks: enter several peaks from your spectrum with their splittings, or paste a list such as "2.05 s; 4.12 q; 1.26 t". Impurities are ranked by the number of matching signals, closeness and splitting agreement.
• The solvent's own residual peaks and the water peak are searched too.
SOLVENTS
• 20 deuterated solvents: residual ¹H and ¹³C peaks, J(H,D) and J(C,D) values, water/HOD peak, density, melting and boiling point, dielectric constant and storage conditions.
• Temperature-dependent HDO shift calculator for D₂O.
IMPURITIES
• More than 3000 ¹H and ¹³C values for 86 common impurities in 12 deuterated solvents.
• Search by English or Turkish name, abbreviation (EtOAc, DCM, THF…) or formula.
• The source publication of every value is shown.
CHEM21 GREEN CHEMISTRY GUIDE
• Safety, health and environment scores of 75 solvents and their ranking from "recommended" to "highly hazardous".
• An explanation of how the scores are obtained.
RECORDS
• Save search results with a sample name, analysis date and note, and mark the impurities you identified in the spectrum.
• Come back to your records any time, edit them, or copy them as text into your report.
• Records are stored only on your device.
MORE
• English and Turkish interface, six colour themes, light and dark mode.
• No internet connection needed; no account, no ads, no data collection.
• Free and open source (GPL-3.0).
SOURCES
The data were compiled from the peer-reviewed literature and a manufacturer's solvent chart:
• H. E. Gottlieb, V. Kotlyar, A. Nudelman, J. Org. Chem. 1997, 62, 7512.
• G. R. Fulmer et al., Organometallics 2010, 29, 2176.
• N. R. Babij et al., Org. Process Res. Dev. 2016, 20, 661.
• D. Prat et al., Green Chem. 2016, 18, 288 (CHEM21).
• Cambridge Isotope Laboratories, NMR Solvent Data Chart.
Chemical shifts can vary with concentration, temperature and pH; consult the original sources and your own measurements for a definitive assignment. This app is not affiliated with the publishers or with Cambridge Isotope Laboratories.
Developer: Dr. İlker ÜN
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What's New in NMR Solvent Impurities
1.0
October 3, 2026






