title: Partitioning of fluorotelomer alcohols (FTOH) to semipermeable membrane devices (SPMD).
abstract: OBJECTIVE
  Fluorotelomer alcohols (FTOH) are widely used substances that were detected even in remote regions of the world. For the determination of FTOH in the atmosphere, appropriate sampling techniques are needed. In this study, triolein-filled low-density polyethylene tubes were used as semipermeable membrane devices (SPMD) and tested for their suitability as passive air samplers for FTOH.
  
  
  METHODS
  Partitioning to and from SPMD were investigated for four FTOH of different chain length and concentration levels in laboratory and field experiments. FTOH were extracted by liquid-liquid extraction with acetonitrile:n-hexane 1:1 and determined by gas chromatography (GC)-positive ion chemical ionisation mass spectrometry (MS).
  
  
  RESULTS
  FTOH behaved differently depending on applied concentrations. At high FTOH levels, compound passage through the membrane and uptake appeared to be best for 6:2 FTOH, but passage of long-chain FTOH was in the same order of magnitude. At low FTOH concentration levels, mass transfer and uptake was best for short-chain FTOH. Partitioning of 4:2 FTOH to SPMD exceeded partitioning of 10:2 FTOH by nearly two orders of magnitude.
  
  
  CONCLUSIONS
  FTOH partitioning to SPMD seems to be dependent on the fluorinated chain length and controlled by the SPMD membrane acting as a barrier. Migration of long-chain FTOH through the membrane was hampered, probably due to the oleophobic properties of the fluorinated alkyl chain. Because of the constricted diffusion of FTOH through the SPMD membrane at low FTOH levels, an adequate accumulation in the passive sampler is prevented. Thus, sensitivity of the analytical method in combination with the enrichment of FTOH in SPMD was not sufficient to achieve adequate method detection limit at low FTOH levels.
  
  
  CONCLUSIONS
  Application of SPMD as passive air samplers for FTOH did not seem to be a suitable method for environmentally relevant FTOH concentrations.
  
  
  CONCLUSIONS
  As a consequence, we can only recommend the use of SPMD for FTOH of presumably high contamination levels.
authors.affiliation: Helmholtz Zentrum München, National Research Centre for Environmental Health, Institute of Ecological Chemistry, Ingolstaedter Landstrasse 1, 85764, Neuherberg, Germany. fiedler.stefan@gmx.net
authors.forename: Stefan
authors.initials: S
authors.lastname: Fiedler
authors.forename: Gerd
authors.initials: G
authors.lastname: Pfister
authors.forename: Karl-Werner
authors.initials: KW
authors.lastname: Schramm
mesh_terms: D000438:Alcohols / Q000032:analysis* / Q000737:chemistry; D001272:Atmosphere / Q000737:chemistry*; D003956:Dialysis / Q000295:instrumentation; D004784:Environmental Monitoring / Q000379:methods*; D006845:Hydrocarbons, Fluorinated / Q000032:analysis* / Q000737:chemistry; D007700:Kinetics
chemical_list: D000438:Alcohols; D006845:Hydrocarbons, Fluorinated