Handbook of Size Exclusion Chromatography and Related ...

polymer, a large size filter of 5, 8, or 10 mm is recommended. Examples are shown
below.
Weight-average molecular
weight M w (g/mole)
10 2 –10 4
10 5
10 6
.10 6
Concentration
(g/100 mL) Filter size (mm)
0.1–0.15 0.22
0.1 0.45
0.05–0.08 1.2–3.0
0.03–0.05 5.0–10.0
The mixing method can change the actual MW and MWD. In this work,
different methods were used to prepare three types of samples.
2.2.1 For Solution Samples
The magnetic stirring method at low speed is recommended.
2.2.2 For Solid Samples
It is very difficult to dissolve high MW solid PAM or its copolymers in a highionic-strength
mobile phase directly. A special process is recommended as
follows. Pour about 60 mL filtered water into a bottle and stir the water with a
magnetic stir bar at high speed. Sprinkle the correct amount of solid sample into
the bottle. When the solid sample disperses homogeneously in the water, cap
the bottle tightly and place the bottle containing the sample in a shaker with
low speed at 508C overnight. Remove the sample from the shaker when the
solid sample is dissolved completely. Add the correct amount of salt to the
above sample solution and adjust the total volume to 100 mL by adding filtered
water. Mix the solution very well and filter the solution with an appropriate size
of filter. Degas the polymer solution in a flask, then transfer the polymer
solution to a 4 mL vial.
2.2.3 For Emulsion Samples
Dilute the emulsion sample with xylene or hexane, then precipitate the dilute
solution into isopropyl alcohol (IPA) or acetone. Filter the mixture to obtain the
solid sample. Dry the precipitated sample in a vacuum oven at 408C overnight to
remove the residual IPA or acetone. A solution of the precipitated sample for SEC
analysis can be prepared by the same method used for preparing solid samples.
© 2004 by Marcel Dekker, Inc.