Quality Assurance and Quality Control (QA/QC). Blank injections and system suitability standards were run before executing the chromatographic sequence to ensure our analytical platform was fit for purpose. Blank injections revealed any problems due to impurities in solvents or contaminants in the separation system. System suitability standards were used to ensure mass accuracy, chromatographic peak shape, and retention time before each sequence. An amino acid standard (AAS18 -Sigma-Aldrich) and SPLASH® LIPIDOMIX® (Avanti® Polar Lipids) were used for HILIC and RP chromatography, respectively. Internal standards were not used to assess extraction efficiency due to the insufficient coverage provided by using a small subset of internal standards that would not accurately reflect the biochemical makeup of an entire biological matrix for optimizing an untargeted method. For each run (Table ), an extraction blank containing no biological material was processed in conjunction with all biological extractions. Extraction blanks underwent the sample preparation as its paired biological sample applying the same consumables, solvent(s), and operating procedures. All samples, including extraction blanks, were run in a randomized order with an injection blank ran after every ten samples to assess potential chromatographic carryover.