Use of gas chromatography-ion trap tandem mass spectrometry for the detection and characterization of microorganisms in complex samples.

Gas chromatography-mass spectrometry (GC-MS) can be applied to detect and characterize microorganisms in clinical and environmental samples, and microbial contaminants in biotechnological production cultures. With this approach, unique microbial monomeric compounds, known as chemical markers, are used as analytes. In the present article, two GC-MS-based techniques, viz. GC-ion trap tandem MS (GC-MS-MS) and conventional quadrupole GC-MS used in the selected ion monitoring mode, were compared regarding their ability to detect 3-hydroxy fatty acids, muramic acid, and ergosterol (markers for endotoxin, peptidoglycan, and fungal biomass, respectively) in complex matrices. When using GC-MS-MS, daughter ion spectra were obtained for all markers present in amounts close to the detection limit of the GC-MS. Ion-trap GC-MS-MS shows great promise as a chemical marker analysis technique for application in clinical diagnosis, occupational and public health care, and biotechnology.