Determination of environmental levels of peptidoglycan and lipopolysaccharide using gas chromatography with negative-ion chemical-ionization mass spectrometry utilizing bacterial amino acids and hydroxy fatty acids as biomarkers.
D-Alanine and diaminopimelic acid originating from bacterial peptidoglycans and hydroxy fatty acids from lipopolysaccharides (endotoxins) were analysed by gas chromatography using a chiral column (Chirasil-Val as stationary phase) and selected-ion monitoring detection with negative-ion chemical-ionization mass spectrometry. The amino acids were analysed as N-heptafluorobutyryl isobutyl esters after rapid hydrolysis of peptidoglycan followed by isolation of the amino acids with disposable ion-exchange columns. Racemization of amino acid enantiomers was controlled by using deuterium chloride in the hydrolysis. The hydroxy acids were analysed as O-pentafluorobenzoyl methyl esters. Most of the bacteria present in airborne dust from a poultry confinement building were found to be Gram-positive according to the analytical chemical method whereas the Limulus amoebocyte lysate test suggested the presence of appreciable amounts of lipopolysaccharides of Gram-negative bacteria. Further studies are required to compare the utility of these two methods for determining endotoxins in complex environments.
Sonesson
A
A
Department of Technical Analytical Chemistry, Lund University, Sweden.
Larsson
L
L
Fox
A
A
Westerdahl
G
G
Odham
G
G
D000596:Amino Acids / Q000032:analysis*; D001419:Bacteria / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis*; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D002852:Chromatography, Ion Exchange; D004391:Dust / Q000032:analysis; D005227:Fatty Acids / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006868:Hydrolysis; D008070:Lipopolysaccharides / Q000032:analysis*; D010457:Peptidoglycan / Q000032:analysis*
D000596:Amino Acids; D015415:Biomarkers; D004391:Dust; D005227:Fatty Acids; D008070:Lipopolysaccharides; D010457:Peptidoglycan