title: Measurement of 18 perfluorinated organic acids and amides in human serum using on-line solid-phase extraction.
abstract: We have developed an on-line solid-phase extraction (SPE) method coupled to high-performance liquid chromatography (HPLC)-tandem mass spectrometry (MS/MS) for measuring trace levels of 18 perfluorinated chemicals (3 perfluorosulfonates, 8 perfluorocarboxylates, 7 perfluorosulfonamides) in serum. Without protein precipitation, only dilution with 0.1 M formic acid, one aliquot of 100 microL of serum was injected into a commercial column switching system that allowed for concurrent SPE and HPLC-MS/MS acquisition. First, the analytes were concentrated on a C18 SPE column. Then, this column was placed automatically in front of a C8 analytic HPLC column for chromatographic separation of the analytes. Detection and quantification were done using negative-ion TurboIonSpray ionization, a variant of electrospray ionization, MS/MS. Excellent recovery was achieved for all analytes including the volatile sulfonamide derivatives that could not be determined before using traditional off-line SPE methods. The high throughput and low limits of detection (0.05-0.8 ng/mL) using a small sample volume (100 microL of serum) and isotope dilution quantification make this method suitable for large-scale epidemiologic studies.
authors.affiliation: Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. ZKuklenyik@cdc.gov
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Kuklenyik
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Calafat
mesh_terms: D000143:Acids / Q000737:chemistry; D000577:Amides / Q000097:blood* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D017611:Fluorine Compounds / Q000097:blood* / Q000737:chemistry; D006801:Humans; D009862:Online Systems / Q000295:instrumentation*; D009930:Organic Chemicals / Q000097:blood* / Q000737:chemistry; D052616:Solid Phase Extraction / Q000295:instrumentation* / Q000379:methods*; D053719:Tandem Mass Spectrometry
chemical_list: D000143:Acids; D000577:Amides; D017611:Fluorine Compounds; D009930:Organic Chemicals