Definitions and Abbreviations
| Some of the terminology that Peaksel uses differs from the terminology in other CDS - usually the intent is to make it more precise or more generic to cover a broader set of instruments. Use Ctrl+F or Cmd+F to search for terms on this page. |
Peak Base - the most abundant spectrum value (on the X axis) at specific RT or within a peak. In terms of Mass Spectrometry it’s usually called Base Peak Mass (BPM) - the prevailing m/z. In terms of UV/IR/Vis detectors it’s the wavelength of maximum absorbance.
RT - Retention Time, an X point on a chromatogram. Usually measured in minutes. Peak RT is the time of its highest point.
Batch - a set of instrument Injections grouped together. Usually they represent 1 logical experiment.
DAD (Diode Array Detection) or PDA (Photodiode-Array Detection) - a type of detectors which measures the absorbance of wavelengths in UV and Visible range. Each diode measures some specific wavelengths, and since there are many diodes (an array) we get a whole spectrum gathered with one measurement (as opposed to UV detector which measures only 1 wavelength at a time).
Total Chromatogram aka TIC (Total Ion Chromatogram) in Mass Spec, TWC (Total Wave Chromatogram) in DAD is the sum of all intensities in each spectrum. As opposed to Extracted Chromatogram.
Extracted Chromatogram - in Mass Spec it’s an EIC (Extracted Ion Chromatogram), in DAD it’s a chromatogram with some particular wavelength. As opposed to Total Chromatogram.
EMW (exact molecular weight) - the molecular weight of the primary isotope of a compound.
Injection - represents data (spectra, chromatograms) with all detector measurements for the injected aliquot. Note that it’s not the same as Sample - which can be injected multiple times.
MISER (Multiple Injections in a Single Experimental Run) - is a way to leverage Flow Injection Analysis (FIA) of analytical instruments. Typical workflow is injecting a sample, then washing, then injecting again. In MISER runs you inject, then inject again without washing. In the end you wind up with a single long chromatogram for many injections. This may not be as clean (because column could be dirtied), but it’s a way of speeding up analysis. Peaksel will split MISER chromatogram into many different injections and will report values for each of them separately to simplify further data analysis.
LargestPeak - peak with maximum area count among the peaks of the same analyte on the same chromatogram.
MF - Molecular Formula
Sample - a mixture or a pure compound that needs to be analyzed. Sample can be injected multiple times resulting in multiple Injections, so these are not synonyms.