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HAAKE™ PolyLab™ OS Modular Torque Rheometer
Thermo Scientific™
The Thermo Scientific™ HAAKE PolyLab OS is a state-of-the-art measuring mixer and extruder system that is focused on the specific needs in research and development. The HAAKE PolyLab OS provides you with process-relevant material data including: Melting behavior, influence of additives, temperature stability, shear stability and melt viscosity. Furthermore, this measuring mixer and extruder system supports you in process modelling activities such as: Compounding polymers with additives to reduce flammability, viscosity, etc., scale-up extrusion processes by using different L/D ratios to extrapolate to your master process line, simulating master processes using only as little as 50g of material to optimize extrusion or mixing in respect to temperature and shear profile or extrusion of strands, profiles or films in combination with rheological or optical measurements. More
HPLC,UHPLC,SFC Columns From Japan
 
COSMOCORE 2.6PBr 
- Separate hydrophilic compounds in reversed-phase conditions
- Retain hydrophilic compounds longer than C18
- Greater sample loading capacity than HILIC
- High performance similar to sub-2 µm particles with lower back pressure
Suitable Samples
- Hydrophilic compounds
- Nucleic acids and derivatives
- Surfactants
- Glycosides
- Peptides
Separation of Hydrophilic Compounds (low retention on C18)
COSMOSIL PBr retains hydrophilic compounds stronger than C18 columns under the same reversed-phase conditions.
Separation Mechanism
Dispersion force (instantaneous dipole–induced dipole force)
London dispersion force is a weak intermolecular force that results from dipoles temporarily induced by random unsymmetrical electron positions in two adjacent atoms, also known as instantaneous dipole–induced dipole force. It is present in all molecules regardless of polarity. Compounds with high polarizability have stronger dispersion force.
Compounds with stronger dispersion force
- Larger and heavier molecules
- Molecules with larger and heavier atoms (e.g. from weakest to strongest in halogens, F2, Cl2, Br2, and I2)
- Molecules with delocalized electrons and resonance (e.g. aromatic compounds)
⇓
COSMOSIL PBr column is packed with pentabromobenzyl-bonded silica that enables separation by dispersion force interaction.
Comparison to HILIC
Both columns are suitable for analysis of hydrophilic compounds, but they have different properties.
| |
PBr |
HILIC |
Separation
Mode |
Reversed Phase |
Hydrophilic Interaction (HILIC) |
| Features |
- Simple mobile phase conditions compared to HILIC.
- Strong eluent: organic (methanol) Weak eluent: water
- Low peak distortion with water-based samples; usable with large injection volumes of dilute samples.
- Some hydrophilic compounds are not retained well.
|
- Retains hydrophilic compounds that would not be retained by C18 columns.
- Strong eluent: water Weak eluent: organic (acetonitrile)
- Peak distortion occurs with large volumes of samples dissolved in water.
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