title: [The metal content of natural waters].
abstract: The authors give the results of their studies for the presence of metals in waters. The investigations are carried out in two directions; the first is related to the solving of pure analytical problems, the second--to the behaviour of the metal ions in water media and hygienic evaluation of their level. Several variants of atomic absorption spectrometry (AAS) are comparatively studied: by flame--directly and by means of extraction concentration and without flame AAS--with and without matrix effects. The analytical parameters of the mentioned methods are determined as well as the experience of their use according to the expected concentration of metals and type of waters. It is established that the content of metals in underground waters is comparatively lower and with no seasonal, local and regional differences. The presence and concentrations of the latter in surface waters is affected by the anthropogenic factors and show a tendency towards fluctuation in type and place. It is also proved that metals have different behaviour in the water media stimulating a diverse tendency towards distribution between water phase, suspending material and bottom sediments.
authors.forename: S
authors.initials: S
authors.lastname: Gitsova
authors.forename: S
authors.initials: S
authors.lastname: Ianeva
authors.forename: S
authors.initials: S
authors.lastname: Mladenova
mesh_terms: D002031:Bulgaria; D002104:Cadmium / Q000032:analysis; D007854:Lead / Q000032:analysis; D008670:Metals / Q000032:analysis*; D013054:Spectrophotometry, Atomic / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D002104:Cadmium; D007854:Lead
vernacular_title: Sŭdŭrrzhanie na metali v prirodni vodi.