title: Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry.
abstract: A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with (198)Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) μg L(-1) could be performed with uncertainty amplification factors <2. A limit of quantification of 0.03 μg L(-1) was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were <10% at added concentration levels of 0.14 μg L(-1), 0.35 μg L(-1) and 2.8 μg L(-1), with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; <0.03-0.19) μg L(-1). This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.
authors.affiliation: ALS Scandinavia AB, Aurorum 10, 977 75 Luleå, Sweden. douglas.baxter@alsglobal.com
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Baxter
authors.forename: Mikko
authors.initials: M
authors.lastname: Faarinen
authors.forename: Heléne
authors.initials: H
authors.lastname: Österlund
authors.forename: Ilia
authors.initials: I
authors.lastname: Rodushkin
authors.forename: Morten
authors.initials: M
authors.lastname: Christensen
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007553:Isotope Labeling; D008297:Male; D008629:Mercury Isotopes / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D008767:Methylmercury Compounds / Q000097:blood*; D014867:Water / Q000737:chemistry
chemical_list: D008629:Mercury Isotopes; D008767:Methylmercury Compounds; D014867:Water; D008752:Methylene Chloride