LIQUID: an‐open source software for identifying lipids in LC‐MS/MS‐based lipidomics data

Summary: We introduce an open‐source software, LIQUID, for semi‐automated processing and visualization of LC‐MS/MS‐based lipidomics data. LIQUID provides users with the capability to process high throughput data and contains a customizable target library and scoring model per project needs. The graphical user interface provides visualization of multiple lines of spectral evidence for each lipid identification, allowing rapid examination of data for making confident identifications of lipid molecular species. LIQUID was compared to other freely available software commonly used to identify lipids and other small molecules (e.g. CFM‐ID, MetFrag, GNPS, LipidBlast and MS‐DIAL), and was found to have a faster processing time to arrive at a higher number of validated lipid identifications. Availability and Implementation: LIQUID is available at http://github.com/PNNL‐Comp‐Mass‐Spec/LIQUID. Contact: jennifer.kyle@pnnl.gov or thomas.metz@pnnl.gov Supplementary information: Supplementary data are available at Bioinformatics online.