Aqueous SEC

Analyte

Polyelectrolytes as well as nonionic watersoluble polymers and polysaccharides

• Sample mass: ~ 100 mg
• Molar mass range: 10³ - 10⁸ g/mol

Equipment

• Eluent: aqueous salt solution (if required with organic co-eluent) e.g. 0.2 M Na₂SO₄+1% HAc
• Detection: refractometer, UV-detector, viscometer, multi angle laser light scattering (MALLS)
• Special feature: column tempering

Evaluation methods and targets

• Conventional calibration
  with dextran, pullulan, polyvinylpyridinium and polystyrene sulfonic acid
  => average molar masses (M_w , M_n); polydispersity index D
• Universal calibration
  by means of viscometry
  => intrinsic viscosity [ η ]; M_w; M_n; D
• Absolute molar mass determination
  by means of static light scattering
  molar mass weight average M_W; average radius of gyration <R_gz> ; M_n; D

Additionally, in special cases an analysis of copolymer and structure composition can be performed.

Application examples

• Graft copolymerization of cationic monomers on starch (PDF)
• Enzymatic synthesis of high molecular Inulin (PDF)
• Derivatization of starch (PDF)

Contact

Dr. Sylvia Radosta
Research devision
Biopolymers
phone +49 (0) 331/ 568-1608
fax +49 (0) 331/ 568-3116
email Sylvia.Radosta@iap.fraunhofer.de

Comparative and additional methods

• Membrane osmometry (M_n)
• Analytical ultracentrifugation (M_Z; D)
• Static light scattering (M_W; R_Z; A₂)
• Differentialrefraktometrie (dn/dc)
• dynamische Lichtstreuung (d_H)
• Dampfdruckosmometrie (M_n)