SAN plot: A graphical representation of the signal, noise, and artifacts content of spectra

Abstract

The signal‐to‐noise ratio is an important property of NMR spectra. It allows to compare the sensitivity of experiments, the performance of hardware, etc. Its measurement is usually done in a rudimentary manner involving manual operation of selecting separately a region of the spectrum with signal and noise, respectively, applying some operation and returning the signal‐to‐noise ratio. We introduce here a simple method based on the analysis of the distribution of point intensities in one‐ and two‐dimensional spectra. The signal/artifact/noise plots, (SAN plots) allows one to present in a graphical manner qualitative and quantitative information about spectra. It will be shown that besides measuring signal and noise levels, SAN plots are also quite useful to visualize and compare artifacts within a series of spectra. Some basic properties of the SAN plots are illustrated with simple application.

Trendbericht: Kernmagnetische Resonanz

“…Neben Triplet-NOAH-Experimenten, die das gleichzeitige Aufnehmen dreier Standardexperimente ermöglichen, sind für COSY/ TOCSY 9) und TOCSY/HSQC 10) nun weitere, optimierte Sequenzen verfügbar. Auch die gleichzeitige homoentkoppelte Aufnahme von 1 H, 13 Cund 1 H, 15 N-HSQC-Experimenten ist jetzt möglich. 11) Besonders interessant dürften auch das BANGO-SEAX-LOC/H2OBC- 12) sowie das editierte HSQC-CLIP-COSY-Experiment 13) sein.…”

“…14) Von generellem Interesse in der NMR ist zudem der neu entwickelte SAN-Plot. 15) Er dient dazu, Rauschen zu beschreiben und Signale in verrauschten Spektren objektiv zu identifizieren.…”