Spurenanalytik des Thalliums

Thallium diagenesis in lacustrine sediments

“…3f), which is twice as much as that of L. Vose (19 Ϯ 4 pM; Fig. 3m); these concentrations are at the lower end of the range reported for German lakes (10 to 540 pM; Sager, 1986) and for the North American Great Lakes (6 to 126 pM; Cheam et al, 1995). The [Tl] profiles for L. Vose (Fig.…”

Biomethylation of thallium by bacteria and first determination of biogenic dimethylthallium in the ocean

“…However, it is not quite clear why dimethylthallium was not found in the incubation experiment with the same lake sediment when 10 "g instead of 0.5 "g thallium(I) was added. One explanation may be that too high a concentration of thallium can reduce the activity of microorganisms, 18 which possibly hinders significant formation of Me 2 Tl . Surface seawater concentrations in the Atlantic Ocean Tables 2 and 3, respectively, where the exact position and date of sampling as well as the results of the dimethylthallium and total thallium determinations are presented.…”

“…This may have been due to the extremely low concentration level of thallium in the environment, for example in the range of about 10-20 ng l À1 in ocean water. 18 Recently, a sensitive and highly selective method for the analysis of dimethylthallium was developed by Schedlbauer and Heumann, which allows the determination of Me 2 Tl traces, e.g. in ocean water down to the sub-nanogram per litre level.…”

Analytical methods and quality assurance

“…The phytoavailability of the element depends on plant species and plant parts (Kemper, Bertram, 1991;Tremel et al, 1997b;Martin, Kaplan, 1998). Several analytical procedures can be used for the determination of thallium (Sager, 1986). Flame atomic absorption spectrophotometry and inductively coupled plasma emission spectrometry are not very sensitive for the determination without preconcentration (Otruba et al, 1994).…”