title: Flame-induced atmospheric pressure chemical ionization mass spectrometry.
abstract: BACKGROUND
  Charged species such as formylium (CHO(+) ), hydronium (H3 O(+) ), and water clusters [H3 O(+) (H2 O)n ] are commonly found in flames. These highly reactive species can react with analytes via ion-molecule reactions (IMRs) to form analyte ions. A new mass spectrometric technique, named flame-induced atmospheric pressure chemical ionization mass spectrometry (FAPCI-MS), was developed to characterize organic compounds via these mechanisms.
  
  
  METHODS
  A commercial corona-discharge atmospheric pressure chemical ionization (APCI) source was modified by replacing the corona needle with a flame to make a FAPCI source. Liquid samples were vaporized in a heated tube and delivered to the IMRs region by nitrogen to react with the charged species generated by a flame. Analytes on surfaces were directly desorbed and ionized by a flame using the technique called desorption-FAPCI-MS (DFAPCI-MS).
  
  
  RESULTS
  Intact molecular ions of various chemical and biological compounds were successfully characterized by FAPCI-MS. The FAPCI mass spectra are nearly identical to those obtained by traditional APCI-MS. The limit of detection (LOD) of reserpine by FAPCI-MS was 50 μg L(-1) with a linear calibration curve (R(2) = 0.9947) from 100 μg L(-1) to 10 mg L(-1) . The LOD for ketamine by DFAPCI-MS was estimated to be less than 0.1 ng.
  
  
  CONCLUSIONS
  In FAPCI, analytes are not incinerated but vaporized and introduced into the ion source to react with the reactive charged species generated by a flame. The features of the FAPCI source include: configuration is very simple, operation is easy, high voltage or inert gas is unnecessary, and the source is maintenance free. Various combustible gases, solvents and solids are useful flame fuels for FAPCI. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Sy-Chyi
authors.initials: SC
authors.lastname: Cheng
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Yen-Ting
authors.initials: YT
authors.lastname: Chen
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan.
authors.forename: Siou-Sian
authors.initials: SS
authors.lastname: Jhang
authors.affiliation: Department of Chemistry, National Sun Yat-Sen University, Kaohsiung, Taiwan.|Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Jentaie
authors.initials: J
authors.lastname: Shiea
mesh_terms: D001274:Atmospheric Pressure; D057230:Limit of Detection; D016014:Linear Models; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry; D004364:Pharmaceutical Preparations / Q000032:analysis / Q000737:chemistry
chemical_list: D009930:Organic Chemicals; D004364:Pharmaceutical Preparations