I am trying to analyze a dataset that includes concentrations of lipids from an MS lipidomics analysis. I don't have the raw data or anything other than an Excel sheet showing samples and their lipid concentration. Many lipid names use the stereospecific naming convention (-sn1, -sn2) as well as naming isomers separately (-iso1, -iso2).
Because I am only interested in comparing species concentrations, would it be a good idea to add up all concentrations of the lipids that share a species but are different isomers or stereoisomers? For example, I would take LPE 22:6-sn2, with a (log scaled) concentration of 0.0012 together with LPE 22:6-sn1 with its concentration of 0.002, add them up, and say I have a total concentration for LPE 22:6 of 0.0032.
Would this be a valid way to go about the analysis? Or am I missing something important?
