GAS CHROMATOGRAPHY-TANDEM MASS-SPECTROMETRY FOR TRACE DETECTION OF MURAMIC ACID, A PEPTIDOGLYCAN CHEMICAL MARKER, IN ORGANIC DUST

Muramic acid (MA) is a chemical marker for bacterial peptidoglycan. MA was analyzed (as its alditol acetate) at trace levels in organic dust using electron impact gas chromatography-tandem mass spectrometry (GC-MS-MS) and gas chromatography-mass spectrometry (GC-MS). GC-MS-MS in the multiple ion reaction mode (MRM) was demonstrated to exhibit considerably decreased background over GC-MS in the selected ion mode (SIM), MA was readily detected in air conditioning and house dust and extraneous peaks were not observed in chromatograms of plants or fungi in the MA region. GC-MS-MS has considerable potential as a tool for trace detection of muramic acid in organic dust and other complex matrices.