QCISNormAreas of chemical features extracted in Cassava Diversity ROOT extracts_2016-2020 crops_input for MVA
Description
Normalized areas of chemical features detected in cassava root tissue of a diversity collection of Latin American cassava accessions. Semi-polar extracts of cassava root tissue harvested between 2016 and 2020 were analysed in an LC-MS system Agilent 6560 Q-TOF in ESI negative mode and C18 reverse phase column as chromatographic separation. Chemical features annotated by retention time (RT) and mass are arranged in rows and samples in columns.
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Steps to reproduce
Batch correction of LC-MS untargeted data (peak areas) was applied using quality control samples (QC) inserted every 25 analytical runs. Quality control samples represent a mixture of all accessions analysed in the diversity panel. Every chemical feature per sample was divided by its homologue in the QC. In addition, normalisation against area of internal standard was performed. Missing values were input by using the median value of each mass, and those presenting over 75% of missing values were excluded from analysis. The resulting data matrix (IS and QC corrected) was then used as input for multivariate analysis (PCA, HCA and OPLS-DA).