IonPac CS14 Manual
Doc. No. 034848-10
Page 14 of 54
B.
Use Fluka or Aldrich Methanesulfonic Acid (MSA) (>99% pure).
C.
In the Chemical Suppression Mode of operation, use Dionex Cation Regenerant Solution (tetrabutylammonium
hydroxide (TBAOH), P/N 039602) to ensure maximum system performance when operating with a CSRS ULTRA (4-
mm) or (2-mm).
D.
Use BAKER INSTRA-ANALYZED
®
or Aldrich Trifluoroacetic Acid
E.
Use Aldrich 18-Crown-6 (99% pure).
F.
Use Aldrich Pyrophosphoric Acid (97% pure).
4.3.3 Eluents with Solvents
Solvents can be added to the ionic eluents used with IonPac CS14 columns to modify the ion exchange process or improve
sample solubility. The solvents used must be free of ionic impurities. However, since most manufacturers of solvents do not
test for ionic impurities, it is important that the highest grade of solvents available be used. Currently, several manufacturers
are making ultrahigh purity solvents that are compatible for HPLC and spectrophotometric applications. These ultrahigh
purity solvents will usually ensure that your chromatography is not affected by ionic impurities in the solvent. Currently at
Dionex, we have obtained consistent results using High Purity Solvents manufactured by Burdick and Jackson and Optima
®
Solvents by Fisher Scientific.
When using a solvent in an ionic eluent, column generated back pressures will depend on the solvent used, concentration of
the solvent, the ionic strength of the eluent and the flow rate used. The column back pressure will vary as the composition of
water-acetonitrile mixture varies. The practical back pressure limit for the IonPac CS14 columns is 4,000 psi (27.57 MPa).
The IonPac CS14 is compatible with the HPLC solvents listed in Table 5, “HPLC Solvents for Use with the CS14 Columns.”
Solvents and water should be premixed in concentrations which allow proper mixing by the gradient pump and to minimize
outgassing. Ensure that all of the inorganic chemicals are soluble in the highest solvent concentration to be used during the
analysis.
Table 5
HPLC Solvents for Use with IonPac CS14 Columns
Solvent
Maximum Operating Concentration
Acetonitrile
100%
Methanol
100%
2-Propanol
100%
Tetrahydrofuran
20%
4.4
Making and Using Eluents that Contain Solvents
When mixing solvents with water remember to mix solvent with water on a volume to volume basis.
If a procedure requires an
eluent of 90% acetonitrile, prepare the eluent by adding 900 mL of acetonitrile to an eluent reservoir. Then add 100 mL of
deionized water or eluent concentrate to the acetonitrile in the reservoir. Using this procedure to mix solvents with water will
ensure that a consistent true volume/volume eluent is obtained. Premixing water with solvent will minimize the possibility of
outgassing.
