Eine neue Methode zur Bestimmung des Tannins

Ohne Zusammenfassung     

Zur Frage der Gewichtsbestimmung kleiner Mengen von Rubidium

Ohne Zusammenfassung     

Determination of antimony species with high-performance liquid chromatography using element specific detection

A new method for the fast and simultaneous determination of Sb(III) and Sb(V) is presented involving the use of anion exchange high-performance liquid chromatography (HPLC), a complexing reagent in the mobile phase, and element specific detection with flame atomic absorption spectrometry (FAAS) or inductively coupled plasma mass spectrometry (ICP-MS). Chromatographic parameters such as nature and concentration of the complexing and eluting compounds and pH of the mobile phase were investigated in detail. Additionally, the separation of inorganic Sb(III) and Sb(V) from organically bounded antimony (as (CH₃)₃SbCl₂ and (CH₃)₃Sb(OH)₂) was investigated by using anion, and cation exchange, and reversed phase HPLC. Best separation was obtained with anion exchange HPLC under alkaline conditions. Cation exchange and reversed-phase HPLC were not useful for the separation of the above compounds. With FAAS concentrations in the upper mg L^–1 range are detectable, which is not sensitive enough for the analyses of environmental samples. When the chromatographic system was coupled to ICP-MS, the detection limits are in the lower μg L^–1 range. The method was applied to various environmental samples with anthropogenic and naturally elevated Sb concentrations.     

Determination of volatile metal and metalloid compounds in gases from domestic waste deposits with GC/ICP-MS

Low temperature GC coupled on-line with ICP-MS was used to identify volatile metal and metalloid compounds in gases and condensates from a domestic waste deposit. Seven tin species could be identified by external standard addition and further volatile compounds of tin, bismuth, mercury, arsenic, antimony and tellurium could be found by boiling point calibration, respectively. Some technical and methodical concepts towards quantification of the results are indicated.     

Opto-galvanic spectroscopy of some molecules in discharges: NH2, NO2, H2 and N2

The change of the discharge voltage when laser light crossing the discharge is tuned to a molecular transition has been measured. Experiments have been performed in the wavelength region between 570 nm and 620 nm with discharges in NH₃, NO₂, H₂, N₂, O₂ and argon. Transitions from the ground states of NH₂ and NO₂ and transitions from metastable states of N₂ and H₂ have been detected. The spacial dependence of the opto galvanic in a low pressure dc-discharge of H₂ and N₂ has been studied.     

Photodetachment measurements of alkali negative ions

Cross sections of alkali negative ions from 0.45 eV up to about 2.5 eV photon energy were measured. Electron affinities of the corresponding atoms are derived from the low energy onsets: EA(Li)=0.611 eV, EA(Na)=0.539 eV, EA(K)=0.497 eV, EA(Rb)=0.490 eV and EA(Cs)=0.470 eV with an estimated uncertainty of ±0.020 eV.