Techniques to measure Molar Mass Distributions

Size based liquid chromatography hyphenated with intelligent detection

GPC/SEC/GFC and HT-GPC Services

PSS uses GPC/SEC/GFC to measure the molar mass distribution. 

  • Mobile Phases
  • Detection (Standard)*
  • Detection (Options)*
  • Hyphenation

Typical mobile phases are

  • Tetrahydrofuran, THF
  • Toluene
  • Choroform
  • Dimethylformamide, DMF
  • Dimethylacetamide, DMAc
  • Dimethylsulfoxide, DMSO
  • N-Methyl-2-pyrrolidone, NMF
  • Hexafluoroisopropanol, HFIP
  • Trifluoroethanol, TFE
  • Trichlorobenzene, TCB
  • Diclorobenzene, DCB
  • Water
  • PBS

If required salts or modifiers will be added to ensure for interaction free size separation.


  • Differential Refractive Index Detection, RI or, if possible, UV/VIS at specific wavelength

High Temperature GPC

  • Infrared Detection, IR (specific wavelength CH2, CH3 or C=O) or Differential Refractive Index Detection, RI

*without brand/manufacturer information: different brands/manufacturers available


  • UV/VIS detection (specific wavelength) or DAD/PDA (spectra)
  • Right Angle Light Scattering (Multi color), PSS SLD1000
  • Dual Angle Light Scattering detection, PSS SECcurity MDS
  • Dynamic Light Scattering detection, PSS BioSECcurity MDS
  • 7 angle Multi Angle Light Scattering, PSS SLD7100
  • Viscosity detection, PSS DVD1260 viscometer
  • Triple plus detection, DVD1260 viscometer and SLD7100
  • Fluorescence detection (specific wavelength or spectra)
  • Thermo Fisher EXQ ESI sprectrometer

High Temperature GPC

  • HT-Evapoarative Light Scattering Detection, PSS GPC 220 SECcurity² ELSD
  • Dual Angle Light Scattering Detection
  • Viscosity,

*without brand/manufacturer information: different brands/manufacturers available

GPC/SEC/GFC searations can be hyphenated with:

  • static light scattering (right angle, dual angle, multi angle)
  • dynamic light scattering
  • triple detection
  • viscometry
  • FTIR (in solution/flow mode)
  • FTIR (evaporation mode/LC Transform)
  • Mass spectrometry - ESI
  • Mass spectrometry - MALDI
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PSS provides GPC/SEC/HT-GPC in different mobile phases at temperatures up to 155°C to compare samples and to obtain molar mass averages and molar mass distributions. In accordance with the requirements of each individual application, we employ various instrument setups, configurations and detectors. The analysis fee for the first sample includes calibration, validation and verification of the system according to the PSS quality system.

Techniques to measure Chemical Composition

Interaction Chromatography and 2D Chromatography

IPC and 2D Services

 PSS applies different Interaction Polymer Chromatography (IPC) techniques to investigate chemical composition distributions.

  • Techniques applied
  • 2D Chromatography
  • Interaction Polymer Chromatography (IPC)
    • Isocratic/Gradient Chromatography
    • Chromatography under Critical Conditions
    • Chromatography under Limiting Conditions
  • SEC-Gradient
  • Temperature Gradient Interaction Chromatography (TGIC)
  • Temperature Rising Elution Fractionation (TREF)

2-dimensional chromatography allows for in-depth characterization. PSS operates instrumentation to offer the following techniques

  • offline 2D setups
    • Fraction collection using fraction collectors
    • Fraction collection using storage loops
  • online 2D setups
    • heart-cutting approach
    • comprehensive approach with
      • < 52 transfer injections per sample
      • < 100 transfer injections per sample
      • < 250 tranfer injections per sample
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In contrast to GPC/SEC Interaction Polymer Chromatography (IPC) allows for separations based on chemical composition or end groups. This service involves an initial consultation with our analytical services staff to determine the most effective analytical methods to use. In accordance with the requirements of each individual application, we employ various instrument setups, configurations and detectors. IPC techniques can be hyphenated with GPC/SEC/GFC to allow for 2-dimensional separations.

Techniques for Identification and Determination of Material Properties

Spectroscopy, Mass Spectrometry and more

Services for Identification and Material Properties Determination

  • NMR
  • Light Scattering
  • DSC
  • TGA
  • EA

Nuclear Magnetic Resonance Spectroscopy (13C, 1H)
NMR provides detailed structural information on macromolecules and is used to determine

  • Monomer types
  • Tacticity
  • Mn, number avergage molecular weight 
  • End groups
  • Co-monomer ratios


Static light scattering

SLS measures the intensity of the scattered light at one or more (different) scattering angles and is used to determine

  • Mw, weight avergage molecular weight
  • A2, Second virial coefficient
  • Rg,z, z-averaged radius of gyration 


Dynamic light scattering

DLS measures the time dependency of the intensity of the scattered light. It is used to determine

  • Rh, hydrodynamic radius


Fourier Transform Infrared Spectroscopy Analysis/ Attenuated Total Reflection Infrared Spectroscopy
FTIR is mainly used to measure spectra from unknowns. The spectra are compared with reference spectra in a libary to aid identification.
ATR is a sampling technique used in conjunction with IR which enables samples to be examined directly in the solid or liquid state without further preparation.

Differential scanning calorimetry
DSC measures the difference in the amount of heat required to increase the temperature of a sample and a reference as a function of temperature. It is mainly used to determine

  • Melting point/range
  • Heat Capacity
  • Thermal stability
  • Decomposition Temperature
  • Glass Transition

Thermogravimetric Analysis
TGA measures changes in the weight of a sample as a function of temperature and/or time. It is used to determine

  • Degradation temperatures
  • Residual solvent
  • Moisture content
  • Amount of fillers in composite material compositions

Elemental Analysis

Matrix Assisted Laser Desorption Ionization (MALDI)  - Time of flight

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In contrast to fractionating (chromatographic) techniques batch techniques provide average values but no distribution information. A variety of batch methods is used to investigate macromolecules and proteins and to determine material properties such as thermal properties.


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