Fig. 4

An example of data preprocessing and Quality Control for MS data. The workflow begins with the Blank Feature Filtering, and removal of the features below the level of detection. The Standardized Euclidian Distance, the Principal Component Analysis, the Run Order Regression, The Magnitude Difference, the Coefficient of Variation, and the Retention Time tools are used for the diagnostics at the next step. Some tools require log transformed data for the input, and the Log/G-Log Transformation tool is included into the workflow to address that. Multiple summary flags are produced by each tool. The tool’s flags are merged and summarized with the option to delete flagged features