The urease method of sample preparation for GC/MS analysis of intermediary metabolites is presented by its inventor. The method allows one-step follow-up of newborn screening for inborn errors by tandem mass spectrometry by quantifying carbohydrates, organic and amino acids all in a single process.
Shoemaker, J. D. One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure. J. Vis. Exp. (40), e2014, doi:10.3791/2014 (2010).