anti-Blood Group Kell antigen Monoclonal antibody, clone NN0436-13X4

[1] Permeation of various gases through elastomeric O-ring seals can have important effects on the integrity of atmospheric air samples collected in flasks and measured some time later. Depending on the materials and geometry of flasks and valves and on partial pressure differences between sample and surrounding air, the concentrations of different components of air can be significantly altered during storage. The influence of permeation is discussed for O-2/N-2, Ar/N-2, CO2, delta(13) C in CO2, and water vapor. Results of sample storage tests for various flask and valve types and different storage conditions are presented and are compared with theoretical calculations. Effects of permeation can be reduced by maintaining short storage times and small partial pressure differences and by using a new valve design that buffers exchange of gases with surrounding air or by using less permeable materials ( such as Kel-F) as sealing material. General awareness of possible permeation effects helps to achieve more reliable measurements of atmospheric composition with flask sampling techniques.

Cesium is a member of the Group I alkali metals, very reactive earth metals that react vigorously with both air and water. The chemistry of cesium is much like the chemistry of neighboring elements on the periodic table, potassium and rubidium. This close relation creates many problems in plant-life exposed to cesium because it is so easily confused for potassium, an essential nutrient to plants. Radioactive (134)Cs and (137)Cs are also chemically akin to potassium and stable cesium. Uptake of these radioactive isotopes from groundwater by plant-life destroys the plant-life and can potentially expose humans to the radioactive affects of (134)Cs and (137)Cs. Much experimental work has been focused on the separation of (137)Cs from uranium fission products. In previous experimental work performed a column consisting of Kel-F supporting tetraphenylboron (TPB) was utilized to separate (137)Cs from uranium fission products. It is of interest at this time to attempt the separation of (134)Cs from 0.01M EDTA using the same method and Neoflon in the place of Kel-F as the inert support. The results of this experiment give a separation efficiency of 88% and show a linear relationship between the column bed length and the separation efficiency obtained.