title: Development of a compact and simple gas chromatography for oral malodor measurement.
abstract: BACKGROUND
  Volatile sulfur compounds (VSCs) in oral air are the only type of gases correlated with the strength of oral malodor. We developed a compact and simple gas chromatograph (GC) equipped with a newly invented indium oxide semiconductor gas sensor (SCS) for measuring the concentrations of VSCs in mouth air. We have assessed the correlation between measurements with a GC-SCS and those with a regular GC.
  
  
  METHODS
  Oral air samples from randomly selected volunteers were analyzed with both a GC-SCS and a GC with a flame photometric detector (FPD), which is specific to VSCs, and GC-SCS measurements were compared to those obtained by GC-FPD. Subsequently, oral air samples before and after mouthrinsing with 5% ethanol mouthwash were analyzed to determine the effect of ethanol on VSC measurements by GC-SCS.
  
  
  RESULTS
  There were strong correlations between VSC concentrations determined using these two gas chromatography methods (hydrogen sulfide, R=0.821, P<0.0001; methyl mercaptan, R=0.870, P<0.0001; and dimethyl sulfide, R=0.770, P<0.0001). Although GC-SCS can differentiate ethanol and VSCs in oral air samples after mouthrinsing, GC-SCS measurements demonstrated higher values than those obtained by GC-FPD; however, this discrepancy improved over time due to the reduced effect of ethanol.
  
  
  CONCLUSIONS
  The results suggest that GC-SCS may be useful for the diagnosis of halitosis.
authors.affiliation: Department of Oral Health, Nippon Dental University, Tokyo, Japan.
authors.forename: Takatoshi
authors.initials: T
authors.lastname: Murata
authors.forename: Anton
authors.initials: A
authors.lastname: Rahardjo
authors.forename: Yuki
authors.initials: Y
authors.lastname: Fujiyama
authors.forename: Takayuki
authors.initials: T
authors.lastname: Yamaga
authors.forename: Mariko
authors.initials: M
authors.lastname: Hanada
authors.forename: Ken
authors.initials: K
authors.lastname: Yaegaki
authors.forename: Hideo
authors.initials: H
authors.lastname: Miyazaki
mesh_terms: D000293:Adolescent; D000328:Adult; D015374:Biosensing Techniques / Q000295:instrumentation; D001944:Breath Tests / Q000295:instrumentation*; D002712:Chlorides; D002849:Chromatography, Gas / Q000295:instrumentation*; D000431:Ethanol; D005260:Female; D006209:Halitosis / Q000175:diagnosis*; D006801:Humans; D007204:Indium; D008297:Male; D008875:Middle Aged; D009067:Mouthwashes; D010783:Photometry / Q000295:instrumentation; D015203:Reproducibility of Results; D012666:Semiconductors; D018709:Statistics, Nonparametric; D013457:Sulfur Compounds / Q000032:analysis*; D017967:Zinc Compounds
chemical_list: D002712:Chlorides; D009067:Mouthwashes; D013457:Sulfur Compounds; D017967:Zinc Compounds; D007204:Indium; D000431:Ethanol; C047711:indium oxide; C016837:zinc chloride