title: Validation and application of an analytical method for monomethylmercury quantification in aquatic plant tissues.
abstract: An analytical methodology for monomethylmercury (MMHg) determination in aquatic plant tissues with low detection limit (346 pg g(-1)) is proposed. It consists of acid digestion (HBr/CuSO4), cleanup step with a Na2S solution, pre-concentration procedure using a dithizone solution in toluene and quantification by GC-ECD. The performance of the methodology has been tested by determining the MMHg concentrations in the certified reference material Fucus Sea Plant Homogenate--IAEA-140/TM (CRM) and in leaves, stems and roots of the salt marsh plants Sarcocornia fruticosa and Halimione portulacoides. The results obtained for CRM were not statistically different (alpha=0.056) from the certified value and repeatability was lower than 2.5% for the plant samples analyzed. This coefficient of variation was similar to those obtained in the externally quality control using within-batch and between-batch (<1.4%).
authors.affiliation: National Institute for Agronomy and Fisheries Research, IPIMAR, Av. Brasília, 1449-006 Lisboa, Portugal. jcanario@ipimar.pt
authors.forename: João
authors.initials: J
authors.lastname: Canário
authors.forename: Miguel
authors.initials: M
authors.lastname: Caetano
authors.forename: Carlos
authors.initials: C
authors.lastname: Vale