Quantitative analysis of amino and organic acids by methyl chloroformate derivatization and GC-MS/MS analysis

Methods Mol Biol. 2014:1198:137-45. doi: 10.1007/978-1-4939-1258-2_10.

Abstract

Alkyl chloroformates are known for their ability to produce mixed anhydrides, and they have found use as versatile derivatization reagents for gas chromatographic (GC) separation of amino- and organic acids. Triple-quadrupole mass spectrometers are excellent detectors for high sensitive and selective analysis. Here, we describe a methyl chloroformate (MCF) GC-MS/MS method for the quantitative analysis of metabolites containing amino- and/or carboxylic groups. The method covers over 60 metabolites with quantitation limits down to the low picomole range injected on column, and any metabolite with amino- and/or carboxylic acid functional groups that yield a stable and volatile MCF derivative can be included in the method. Absolute quantitation can be achieved by including a stable isotope-coded derivatization agent (d3-MCF) and deuterated alcohol solvent (e.g., d4-methanol). As the carboxylic and amino groups are differently labeled, the former from the solvent methanol while the latter from MCF, this approach can also be used to identify a number of amino and carboxylic groups in unknown analytes in an extract.

MeSH terms

  • Amino Acids / analysis*
  • Amino Acids / metabolism
  • Animals
  • Carboxylic Acids / analysis*
  • Carboxylic Acids / metabolism
  • Formates / chemistry*
  • Gas Chromatography-Mass Spectrometry / methods*
  • Humans
  • Metabolome
  • Metabolomics / methods
  • Tandem Mass Spectrometry / methods*

Substances

  • Amino Acids
  • Carboxylic Acids
  • Formates
  • methyl chloroformate