Optimizing Spectroscopic Signal-to-Noise Ratio in Analysis of Data Collected by a Chromatographic/Spectroscopic...

To get an accurate spectrum across a chromatographic peak when analyzing data collected from a chromatography/spectroscopy experiment such as liquid chromatography/mass spectrometry, it is often necessary to sum or average the spectra collected across the chromatographic peak. A common practice is to sum the spectra collected across the entire duration of the chromatographic peak. However, this practice is not ideal in terms of optimizing the signal-to-noise ratio (S/N) of the sum spectrum. In most instances, the spectral signals may be so weak at the earlier and later ends of the chromatographic peak that summing these spectra into the sum spectrum may decrease its overall S/N. This report describes some simple guidelines and methods to analyze data collected by a chromatography/spectroscopy system to achieve the maximum S/N from the available data. More specifically, to achieve a better S/N when summing spectra within one chromatographic peak, only the spectra whose relative abundance is above 38% should be included. To achieve the maximum possible S/N, a matched filter should be applied to the data before the spectra are summed.