title: Polar stir bars for isolation and preconcentration of perfluoroalkyl substances from human milk samples prior to UHPLC-MS/MS analysis.
abstract: BACKGROUND
  A new method for the determination of four perfluoroalkyl carboxylic acids (from C5 to C8) and perfluorooctane sulfonate in human milk samples using stir-bar sorptive extraction-ultra-HPLC-MS/MS has been accurately optimized and validated.
  
  
  METHODS
  Polydimethylsiloxane and polyethyleneglycol modified silicone materials were evaluated.
  
  
  CONCLUSIONS
  Overall, polyethyleneglycol led to a better sensitivity. After optimizing experimental variables, the method was validated reaching detection limits in the range of 0.05-0.20 ng ml(-1); recovery rates from 81 to 105% and relative standard deviations fewer than 13% in all cases. The method was applied to milk samples from five randomly selected women. All samples were positive for at least one of the target compounds with concentrations ranging between 0.8 and 6.6 ng ml(-1), being the most abundant perfluorooctane sulfonate.
authors.affiliation: Department of Analytical Chemistry, Superior Polytechnic School, University of Seville, C/Virgen de África 7, E-41011 Seville, Spain.
authors.forename: Julia
authors.initials: J
authors.lastname: Martín
authors.affiliation: Research Group of Analytical Chemistry & Life Sciences, Department of Analytical Chemistry, University of Granada, Campus of Fuentenueva, E-18071 Granada, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Rodríguez-Gómez
authors.affiliation: Research Group of Analytical Chemistry & Life Sciences, Department of Analytical Chemistry, University of Granada, Campus of Fuentenueva, E-18071 Granada, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Zafra-Gómez
authors.affiliation: Department of Analytical Chemistry, Superior Polytechnic School, University of Seville, C/Virgen de África 7, E-41011 Seville, Spain.
authors.forename: Esteban
authors.initials: E
authors.lastname: Alonso
authors.affiliation: Research Group of Analytical Chemistry & Life Sciences, Department of Analytical Chemistry, University of Granada, Campus of Fuentenueva, E-18071 Granada, Spain.
authors.forename: José L
authors.initials: JL
authors.lastname: Vílchez
authors.affiliation: Research Group of Analytical Chemistry & Life Sciences, Department of Analytical Chemistry, University of Granada, Campus of Fuentenueva, E-18071 Granada, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Navalón
mesh_terms: D000327:Adsorption; D017738:Alkanesulfonic Acids / Q000032:analysis / Q000302:isolation & purification / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000592:standards; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D052244:Endocrine Disruptors / Q000032:analysis / Q000302:isolation & purification / Q000592:standards; D005260:Female; D005466:Fluorocarbons / Q000032:analysis* / Q000302:isolation & purification / Q000592:standards; D005590:Fractional Precipitation; D006801:Humans; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D008895:Milk, Human / Q000737:chemistry*; D011786:Quality Control; D012828:Silicones / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry / Q000592:standards
chemical_list: D017738:Alkanesulfonic Acids; D004129:Dimethylpolysiloxanes; D052244:Endocrine Disruptors; D005466:Fluorocarbons; D012828:Silicones; D012965:Sodium Chloride; C013830:baysilon; C076994:perfluorooctane sulfonic acid
keywords: UHPLC–MS/MS; endocrine disrupting chemicals; human milk; perfluoroalkyl substances; sample preparation; stir-bar sorptive extraction