NDCS RCS
Number of Detected Chromatogram Scan (NDCS) and Ratio of Chromatogram Scan (RCS) are two parameters defined in the IDSL.UFA workflow to evaluate detection of theoretical isotopic profile models across a chromatographic peak. In many cases, chromatographic peaks are broad with long tailings and/or frontings; therefore, NDCS and RCS are calculated for the top 80% of chromatographic peak height to prevent peak interferences due to partial co-elutions of similar compounds.
NDCS counts chromatogram scans that match complete isotopic profile models on experimental spectra. NDCS can be used to prevent random matching of isotopologues from various chromatogram scans. The greater NDCS values indicate more individual chromatogram scans matched the isotopic profile ensembles.
RCS is a chromatographic representation of NDCS. When a chromatographic peak only has a few chromatogram scans with compelete isotopic profile match, RCS can be used to evaluate matching an isotopic profile model better than NDCS.