Isogenerator is an exchange column that has
been loaded with 5 microcarriers of cesium-137
(Cs-137). When a 0.1 M EDTA (pH 9.0)
solution is introduced to the column
only the daughter isotope, barium-137,
will be released when the solution is
eluted. The Cs-137 will remain in the
column. The short half-life of the barium-137
makes it ideal for conducting liquid
isotope experiments such as half-life
determination. This system is manufactured
by Oxford instruments Inc. The following
is how to setup the Isogenerator:
1. The first step of preparation
is to remove the large cap above the reservoir.
This may be difficult, due to the vacuum
created in the column itself. This should
be done by holding the column secure in one
hand and using the thumb to push in an upward
motion. Do this slowly to keep the liquid
inside the column. Once this has been accomplished,
place the column in the burette clamp and
mount on the ring stand.
2. With gloves on and a vial under the column,
remove the small cap at the bottom of the column. Catch
the liquid and determine with the Geiger counter that
there is no contamination present. At this point, replace
the small cap with the stopcock provided. Make sure the
stopcock is in the off position. Fill the column with 3
ml of 0.1M EDTA (pH 9.0). Allow the column to sit for
approximately one hour. This moves the barium-137 down
the column, allowing better results on your first
"Milking the Cow."
3. This procedure is very pH specific
and could influence the results of your experiments.
It is suggested that the pH of the EDTA solution
be checked often. Also, the solution should
be replaced every six months.
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