title: One-step extraction and quantitation of toxic alcohols and ethylene glycol in plasma by capillary gas chromatography (GC) with flame ionization detection (FID).
abstract: OBJECTIVE
  Clinical analysis of volatile alcohols (i.e. methanol, ethanol, isopropanol, and metabolite acetone) and ethylene glycol (EG) generally employs separate gas chromatography (GC) methods for analysis. Here, a method for combined analysis of volatile alcohols and EG is described.
  
  
  METHODS
  Volatile alcohols and EG were extracted with 2:1 (v:v) acetonitrile containing internal standards (IS) 1,2 butanediol (for EG) and n-propanol (for alcohols). Samples were analyzed on an Agilent 6890 GC FID. The method was evaluated for precision, accuracy, reproducibility, linearity, selectivity and limit of quantitation (LOQ), followed by correlation to existing GC methods using patient samples, Bio-Rad QC, and in-house prepared QC material.
  
  
  RESULTS
  Inter-day precision was from 6.5-11.3% CV, and linearity was verified from down to 0.6mmol/L up to 150mmol/L for each analyte. The method showed good recovery (~100%) and the LOQ was calculated to be between 0.25 and 0.44mmol/L. Patient correlation against current GC methods showed good agreement (slopes from 1.03-1.12, and y-intercepts from 0 to 0.85mmol/L; R(2)>0.98; N=35). Carryover was negligible for volatile alcohols in the measuring range, and of the potential interferences tested, only toluene and 1,3 propanediol interfered. The method was able to resolve 2,3 butanediol, diethylene glycol, and propylene glycol in addition to the peaks quantified.
  
  
  CONCLUSIONS
  Here we describe a simple procedure for simultaneous analysis of EG and volatile alcohols that comes at low cost and with a simple liquid-liquid extraction requiring no derivitization to obtain adequate sensitivity for clinical specimens.
authors.affiliation: Calgary Laboratory Services, Room C-156, 1st Floor Diagnostic and Scientific Research Centre, #9 3535 Research Rd. NW, Calgary, AB T2L 2K8, Canada.
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Orton
authors.affiliation: Calgary Laboratory Services, Room C-156, 1st Floor Diagnostic and Scientific Research Centre, #9 3535 Research Rd. NW, Calgary, AB T2L 2K8, Canada.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Boyd
authors.affiliation: Calgary Laboratory Services, Room 616, 6th Floor, Foothills Medical Centre, 1403 29 Street NW, Calgary, AB T2N 2T9, Canada.
authors.forename: Darlene
authors.initials: D
authors.lastname: Affleck
authors.affiliation: Calgary Laboratory Services, Room 616, 6th Floor, Foothills Medical Centre, 1403 29 Street NW, Calgary, AB T2N 2T9, Canada.
authors.forename: Donna
authors.initials: D
authors.lastname: Duce
authors.affiliation: The Hospital for Sick Children, 3rd Floor Atrium, Room 3642, 170 Elizabeth Street, Toronto, ON, Canada.
authors.forename: Warren
authors.initials: W
authors.lastname: Walsh
authors.affiliation: Calgary Laboratory Services, Room 616, 6th Floor, Foothills Medical Centre, 1403 29 Street NW, Calgary, AB T2N 2T9, Canada. Electronic address: Isolde.SeidenLong@cls.ab.ca.
authors.forename: Isolde
authors.initials: I
authors.lastname: Seiden-Long
mesh_terms: D000438:Alcohols / Q000097:blood*; D002138:Calibration; D002849:Chromatography, Gas / Q000379:methods*; D019855:Ethylene Glycol / Q000097:blood*; D005410:Flame Ionization / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D011786:Quality Control; D015203:Reproducibility of Results
chemical_list: D000438:Alcohols; D019855:Ethylene Glycol
keywords: Ethylene glycol; Gas chromatography; Toxic alcohols; Volatile alcohols