Open Access Green möglich sobald Postprint bei der ZB eingereicht worden ist.
		
    Effects of carbon dioxide in breath gas on proton transfer reaction-mass spectrometry (PTR-MS) measurements.
        
        Int. J. Mass Spectrom. 270, 156-165 (2008)
    
    
    
				PTR-MS is becoming a common method for the analysis of volatile organic compounds (VOCs) in human breath. Breath gas contains substantial and, particularly for bag samples, highly variable concentrations of water vapour (up to not, vert, similar6.3%) and carbon dioxide (up to not, vert, similar6.5%). The goal of this study was to investigate the effects of carbon dioxide on PTR-MS measurements; such effects can be expected in view of the already well known effects of water vapour. Carbon dioxide caused an increase of the pressure in the PTR-MS drift tube (not, vert, similar1% increase for 5% CO2), and this effect was used to assess the CO2 concentration of breath gas samples along the way with the analysis of VOCs. Carbon dioxide enhanced the concentration ratio of protonated water clusters (H3O+H2O) to protonated water (H3O+) in the drift tube. Using the observed increase, being not, vert, similar60% for 5% CO2, it is estimated that the mobility of water cluster ions in pure CO2 is almost 65% lower than in air. Carbon dioxide had a significant effect on the mass spectra of the main breath gas components methanol, ethanol, 1-propanol, 2-propanol, acetone, and isoprene. Carbon dioxide caused a small increase (<10% for 5% CO2) of the normalised main signals for the non-fragmenting molecules methanol and acetone. The increase can be much higher for the fragmenting VOCs (ethanol, propanol, and isoprene) and was, for 5% CO2, up to not, vert, similar60% for ethanol. This effect of CO2 on fragment patterns is mainly a consequence of the increased abundance of protonated water clusters, which undergo softer reactions with VOCs than the hydronium ions. Breath gas samples stored in Teflon bags lost not, vert, similar80% of CO2 during 3 days, the decrease of VOC signals, however, is mainly attributed to decreasing VOC concentrations and to the loss of humidity from the bags.
			
			
		Impact Factor
					Scopus SNIP
					Web of Science
Times Cited
					Times Cited
Scopus
Cited By
					
					Cited By
Altmetric
					
				2.445
					1.000
					30
					39
					
					
				Anmerkungen
				
					
						 
						
					
				
			
				
			
				Besondere Publikation
				
					
						 
					
				
			
			
			
				Auf Hompepage verbergern
				
					
						 
					
				
			
			
        Publikationstyp
        Artikel: Journalartikel
    
 
    
        Dokumenttyp
        Wissenschaftlicher Artikel
    
 
     
    
    
        Schlagwörter
        Breath gas analysis; PTR-MS; Carbon dioxide
    
 
     
    
    
        Sprache
        englisch
    
 
    
        Veröffentlichungsjahr
        2008
    
 
     
    
        HGF-Berichtsjahr
        2008
    
 
    
    
        ISSN (print) / ISBN
        1387-3806
    
 
    
        e-ISSN
        1873-2798
    
 
     
     
     
	     
	 
	 
    
        Zeitschrift
        International Journal of Mass Spectrometry
    
 
		
    
        Quellenangaben
        
	    Band: 270,  
	    Heft: 3,  
	    Seiten: 156-165 
	    
	    
	
    
 
  
         
        
            Verlag
            Elsevier
        
 
         
	
         
         
         
         
         
	
         
         
         
    
         
         
         
         
         
         
         
    
        Begutachtungsstatus
        Peer reviewed
    
 
    
        Institut(e)
        Institute of Radiation Protection (ISS)
    
 
     
     
    
        PSP-Element(e)
        G-501100-007
    
 
     
     	
    
    
        Scopus ID
        38949089658
    
    
        Erfassungsdatum
        2008-06-25