Waters µStyragel Column - Manual (Page 4)

[ Care and Use ManUal ]
µStyragel Column 4
b. Changing Solvents
To convert a column or column series from one solvent to another:
1. Set the pump to 0.0 mL/min, then turn on the pump.
2. Increase the flow rate gradually in 0.1 mL/min increments to
1.0 mL/min.
3. Purge the column(s) with the new solvent for a minimum of
4 column volumes (at least 48 mL) per column.
√ = Appropriate to use.
• = Caution advised for use with 100Å columns.
X = Do not use with 100Å or 500Å columns.
N/A = Use of this solvent is not advised for these columns.
Table 2: Solvent Column Compatibility
c. Preparing the Sample
Good sample preparation prevents column deterioration and ensures
reproducible results. Take into account operating conditions such as
the loading capability of the column, sample viscosity, and the type
and operating sensitivity of the detector.
Sample filtration Use a 0.45 µm filter to remove micro particulates.
Filtering samples helps to prevent the high back pressures that
result from blocked column inlets. Refer to the Waters Catalog (or
www.waters.com), filtration section for products and solvent compat-
ibility table.
Table 3: Recommended Sample Concentrations
Sample Concentration
Sample concentration affects both viscosity and injection volume.
While small sample amounts produce narrower peaks, viscous
samples may require larger, more dilute sample volumes. Table 3
lists the recommended concentration of sample for optimum results.
In this table, sample concentration is a function of molecular weight.
High Molecular Weight Polymers
High molecular weight polymers are especially susceptible to
viscosity problems. When analyzing high molecular weight polymers,
set concentrations as indicated in Table 3, Recommended Sample
Concentrations. Run narrow-distribution polymers, such as poly-
styrene standards, with an injection volume of 50 µL per column at
concentrations of 0.02%.
Polystyrene standards with molecular weights of approximately
4 million or greater become increasingly susceptible to degradation
by shearing in solution and handling. Indications of this are broader
molecular weight distributions than expected. Standards as high as
8.4 million have been handled successfully with care.
Solvent µStyragel
1,1,1,3,3,3-Hexafluoroisopropanol √
1,1,1-Trifluoroethanol √
Benzene √
Carbon tetrachloride √
Chloroform √
Dimethylacetamide (DMAC) √
Dimethylsulfoxide (DMSO) √
Ethylene dichloride √
m-Cresol √
Methylene chloride √
Methyl ethyl ketone (MEK) N/A
N-Methyl-2-Pyrrolidone √
N, N-Dimethyl Formamide (DMF) √
o-dichlorobenzene (ODCB) •
p-Dioxane √
Phenol √
Tetrahydrofuran (THF) √
Toluene √
Trichlorobenzene (TCB) •
Trichloroethane √
Xylene √
Molecular Weight Range Sample Concentration
0 to 25,000 <0.25%
25,000 to 200,000 <0.1%
200,000 to 2,000,000 <0.05%
Above 2,000,000 <0.02%