title: [Evaluation of uncertainty in determination of heroin by GC].
abstract: OBJECTIVE
  To estimate the inevitable uncertainty of determining heroin by GC.
  
  
  METHODS
  The source of the uncertainty was confirmed from the determining procedure. Each component's uncertainty was calculated. The combined uncertainty was then obtained by synthesizing the uncertainties of various components variables, and the expand uncertainty was finally obtained.
  
  
  RESULTS
  The uncertainty of repeated measurement was greater than other uncertainty components introduced by balance,content vessels and instruments in determining heroin.
  
  
  CONCLUSIONS
  The errors of repeated measurement and GC instrumental were confirmed as the major sources of uncertainty in determining heroin by GC.
authors.affiliation: Institute of Forensic Sciences, Ministry of Justice, PR China, Shanghai 200063, China.
authors.forename: Xian-Yi
authors.initials: XY
authors.lastname: Zhuo
authors.forename: Dong
authors.initials: D
authors.lastname: Ma
authors.forename: Jun
authors.initials: J
authors.lastname: Bu
authors.forename: Bao-hua
authors.initials: BH
authors.lastname: Shen
mesh_terms: D000465:Algorithms; D002849:Chromatography, Gas / Q000379:methods*; D005554:Forensic Medicine / Q000379:methods; D003932:Heroin / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D008962:Models, Theoretical; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry; D015813:Substance Abuse Detection / Q000379:methods; D035501:Uncertainty
chemical_list: D012997:Solvents; D003932:Heroin