Foundation GPC Part 5

1
Foundation GPC Part 5 Polar and Aqueous Gel
Permeation Chromatography Columns and Applications
2
Introduction

• There are a wide variety of columns available
  for polar and aqueous GPC
• This presentation shall introduce the most
  common types of column
• This information can act as a reference
• Applications on the various columns shall also
  be discussed
• We have performed many applications on our
  columns, so even if your application is not shown
  here, weve probably done it!

3
Column Types

• The factor that principally controls which type
  of column is selected for a GPC experiment is
  the solvent
• Many polymer dissolve in only very limited
  numbers of solvents
• The columns used must be compatible with the
  solvent of choice
• Most importantly, the size exclusion mechanism
  must be maintained
• Polymer Laboratories have one range of GPC
  column for aqueous solvents and one for any type
  of solvent
• The properties of each range that must be
  considered when selecting them for an application
  shall be presented

4
Aqueous GPC

• A growing number of polymers are water soluble
• Interest in recycling, renewable resources and
  biomedical applications has led to increased
  interest in this area
• There are lots of different chemistries of
  packing materials employed for aqueous GPC
• Different manufacturers use different column
  types
• Columns are available as individual or MIXED
  type and in a range of pore, particle and column
  dimensions, just like the organic GPC columns
• We shall also discuss a new packing material
  that can be used in organic and aqueous solvents

5
PL Aquagel-OH Columns
6
(No Transcript)
7
Typical Calibrants

• Polyethylene glycol and oxide standards are
  chemically identical except for the end group
• These are common polymer standards for aqueous
  GPC

8

• For biological polymers such as starches and
  other polysaccharides, pullulans provide a more
  realistic result

9
Biopolymers Analysis

• A thickening agent found in foodstuffs
• The MIXED bed column is most suitable to this
  kind of broad polydispersity sample

10

• A blood thickening agent, heparin is fairly low
  in molecular weight
• For these types of samples the individual pore
  size columns are most suited

11
High Molecular Weight Analysis

• High molecular weight samples are best analysed
  on individual pore size columns
• The large particle size reduces the potential
  for shear degradation

12
(No Transcript)
13
Analysis of Hydrophobic Polymers

• Hydrophobic samples will interact in pure water
• Methanol is added to the eluent to inhibit
  interactions

14
Analysis of Cationic Polymers

• Cationic polymers require reduced pH to run
• System imbalance peaks result from preparing the
  samples in a strong acid

15
Analysis of Hydrophobic, Anionic Polymers

• These standards are anionic and hydrophobic
• An increased pH and methanol are required for
  the analysis
• WWater soluble polymers with a UV chromophore

16
PolarGel Columns
17
PolarGel Columns
18
PolarGel-M Calibrations
19
Peak Shapes of Polar Compounds
20
Analysis of Polar Samples

• These materials can interact with PS/DVB columns
• The more polar surface of PolarGel is well
  suited to this application

21
Analysis in Unusual Solvents

• Acetone cannot be used for GPC with PS/DVB, the
  samples do not elute properly
• The more polar surface of the PolarGel column
  allows GPC to be performed