Comparison of serum versus plasma collection in gas chromatography – Mass spectrometry‐based metabolomics

Abstract

Bovine serum, EDTA‐plasma and EDTA‐plasma fortified with acetylsalicylic acid (ASA) as antioxidant were compared with regard to their suitability for metabolomic studies. Metabolic fingerprints were generated from GC‐TOF‐MS data using the Leco ChromaTOF^® software in combination with the in‐house retention time correction and data alignment tool INCA. A total of 6, 9 and 21 significant features with a false discovery rate of versus EDTA‐ASA‐plasma, EDTA‐plasma versus serum and EDTA‐ASA‐plasma versus serum, respectively. To confirm that the observed signal intensities in the GC‐TOF‐MS fingerprints reflected true metabolite abundances, 19 amino acids, glucose and 6 organic acids were quantified by means of GC‐MS using stable‐isotope‐labeled internal standards. As observed with the fingerprints, only the concentrations of lactate and citrate were found to be significantly lower in EDTA‐plasma and serum, respectively, whereas the concentrations of the other metabolites were similar among the three sample types investigated.