Waters IC-Pak Column and Guard - Manual (Page 4)

[ Care and Use ManUal ]
IC-Pak Column and Guard Column 4
Solvents Containing Salts
Changeover between an organic solvent and water containing
salts should be performed gradually using 18 megohm water as
the intermediate solvent. Use care when adding organic solvents
to aqueous buffer solutions as salt precipitation may occur. As a
general rule, do not exceed salt concentrations of 0.1 M.
High pH Mobile Phase
If a high pH mobile phase (greater than 9) is to be used, a soda-
lime or Ascarite
TM absorbing trap is recommended. Otherwise, CO
2
absorption from air contact with the reservoir may cause changes
in pH and ionic strength and impair reproducibility. Sparging with
helium is another recommended method to avoid this problem.
Equilibration
The shipping solvent maintains equilibrium. Flush the newly
attached column with fresh mobile phase before performing the first
separation.
Preparing Eluent for Efficiency Testing
For general use and for efficiency testing (Section IV, b.), prepare
the eluent specified in Table 3.
Table 3: Eluents for Efficiency Testing
*Sodium borate gluconate may be used in place of lithium borate
gluconate if desired. The chromatographic effects of the two eluents
are essentially identical.
b. Lithium Borate/Gluconate Eluent
All reagents should be of the highest purity available. To prepare
Lithium Borate/Gluconate concentrate:
1. To a one liter volumetric flask add:
34 g boric acid (H
3
BO
3
)
23.5 mL d-gluconic acid*
8.6 g lithium hydroxide monohydrate
* The compound d-gluconic acid is available as a 50 wt. percent aqueous
solution (Aldrich or Eastman Kodak).
Note: Sep-Pak ® C
18
clean-up of this reagent is recommended. Clean-up is
complete when a clear solution is obtained.
2. Add approximately 500 mL of Milli-Q ® water and mix thoroughly until
dissolved. Then add 250 mL glycerin.
3. Fill to the mark with Milli-Q water and mix thoroughly. Concentrate
may be stored for up to six months before requiring replacement.
To prepare Lithium Borate Gluconate Eluent, conductivity 240 µS:
1. Place approximately 500 mL of Milli-Q water into a one liter
volumetric flask. To this add:
20 mL borate gluconate concentrate
20 mL n-butanol
120 mL acetonitrile
2. Fill the flask to the mark with Milli-Q water and mix thoroughly. Filter
through a 0.22 µm GHP membrane.
c. Sodium Borate/Gluconate Eluent
All reagents should be of the highest purity available. To prepare
Sodium Borate/Gluconate concentrate:
1. To a one liter volumetric flask add:
16 g sodium gluconate
18 g boric acid
25 g sodium tetraborate decahydrate
2. Add approximately 500 mL of Milli-Q water and mix thoroughly until
dissolved. Then add 250 mL glycerin.
Column Name Eluent Section
IC-Pak A
IC-Pak A HC
IC-Pak A HR
Lithium Borate/Gluconate or
Sodium Borate/Gluconate*
Section III. b)
Section III, c)
IC-Pak C (Monovalent) EDTA/Nitric Acid Section III, d)
IC-Pak C (Divalent) EDA/Nitric Acid Section III, e)