Micromeritics Elzone II 5390 Operator's Manual page 346

Elzone II 5390 Confirm
Preparation of Electrolyte Solutions
Choosing the composition of and preparing an electrolyte for frequently used materials are
relatively straightforward, while for unknowns it most likely will involve some trial and
error. Most often satisfactory electrolytes can be prepared from distilled water or anhy-
drous organic liquids using technical grade salts. Electrolytes must be virtually free of par-
ticles for best results, or at least free of particles above the threshold intended to be used in
any analysis.
Filter cartridges of the high area type provide the best filtration and the easiest handling.
Only a small liquid head and no pumping or pressurizing is required. Filtering rates of 100
mL/min can be achieved with 0.2-micrometer (sterile) filters and greater rates for larger
pore filters. One filter can process many hundreds of liters. Some users prefer to process
only enough electrolyte for one day's operation to avoid contamination problems. This
electrolyte should be held at the same temperature as the area of the analytical instrument
and its container should remain sealed except when actually being poured from.
Only testing for stability with an actual sample of the material in question can prove ade-
quacy. If dissolving, crystallizing, or agglomeration occurs over time, a different composi-
tion obviously is required. Small changes indicative of dissolving usually can be corrected
by pre-saturating the electrolyte.
The instructions given below are for one type of filtering devices available. The one in
your lab may be of a different design and, therefore, will function differently. The impor-
tant thing to remember is that you must use a 0.2-m (or lower) filter.
1. Remove the upper container and rinse with a small amount of electrolyte.
D-4
Upper container
Filter section
Lower container
5539-42822-01 (Rev A) - Nov 2017
Appendix D