title: Real-time ultrasensitive VUV-PIMS detection of representative endogenous volatile markers in cancers.
abstract: BACKGROUND
  Identifying endogenous volatile organic compounds (VOCs) as markers for different cancers currently requires time-consuming procedures and specialized operators.
  
  
  OBJECTIVE
  The objective of this study was to develop a rapid and simple method for measuring VOCs at trace levels.
  
  
  METHODS
  A simple vacuum ultraviolet photoionization mass spectrometer (VUV-PIMS) was used to detect trace levels of dimethyl trisulfide (DMTS), dimethyl sulfide (DMS), and 2-butanone, which correspond to volatile biomarker candidates present in the exhaled breath of patients with breast, liver, and lung cancers, respectively. The practicality of measuring endogenous VOCs using VUV-PIMS was confirmed by detecting them in cultured cell lines.
  
  
  RESULTS
  The abovementioned VOCs were detected with high sensitivity by VUV-PIMS. The limits of detection (LODs) for DMTS, DMS, and 2-butanone were 3.1, 3.9, and 23.2 pptv, respectively, under ambient conditions, which surpass the sensitivity of nearly all other MS-based techniques. Moreover, relatively high concentrations of 2-butanone and DMS were observed in VOCs emitted from the A549 lung cancer cell line and the HepG2 liver cancer cell line, respectively.
  
  
  CONCLUSIONS
  Our results show that VUV-PIMS may serve as a reliable method for real-time measurement of endogenous volatile cancer biomarkers.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Jinian
authors.initials: J
authors.lastname: Shu
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Wanqi
authors.initials: W
authors.lastname: Sun
authors.forename: Bo
authors.initials: B
authors.lastname: Yang
authors.forename: Haixu
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000072283:A549 Cells; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000175:diagnosis; D001944:Breath Tests / Q000379:methods*; D002074:Butanones / Q000032:analysis*; D045744:Cell Line, Tumor; D045853:Exhalation; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D057230:Limit of Detection; D008113:Liver Neoplasms / Q000175:diagnosis; D008175:Lung Neoplasms / Q000175:diagnosis; D013440:Sulfides / Q000032:analysis*; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; D002074:Butanones; D013440:Sulfides; D055549:Volatile Organic Compounds; C054170:dimethyl trisulfide; C005222:methylethyl ketone; C004784:dimethyl sulfide
keywords: VUV-PIMS; cancer; cell measurement; endogenous VOCs