Bettersize
BeSEC
Molecular Weight Analyser
- Measure the absolute molecular weight
- Dual-angle light scattering detector
- Molecular weight range: 1 kDa to 2 GDa
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Key Features and Benefits
Key Features
- Detection angles: 7° and 90°
- Molecular weight range: 1 kDa to 2 GDa
- Supports radius of gyration Rg > 12 nm
- Homopolymer and protein modes
- Acquires RI, UV, and start signals
- Intuitive software with real-time analysis
- 18 μL flow cell reduces band broadening
Benefits
- Proteins: Determine molecular weight, oligomer state, and aggregates
- Ppolymers and polysaccharides: Analyze molecular weight distribution and size
- No column calibration required since Mw is independent of elution volume
- Low-angle detection enables accurate molecular weight
- Compatible with any SEC or GPC system
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Technical Specs
TechnologyBeSEC LS1: 1 kDa to 20 MDa* BeSEC LS2: 1 kDa to 2 GDa*
RgBeSEC LS1: N/A BeSEC LS2: > 12 nm*
Detection AngleBeSEC LS1: RALS (90°) BeSEC LS2: LALS (7°) and RALS (90°)
Laser Source TypeDiode Laser
Laser Power10 mW
Laser Wavelength640 nm
Sample Cell Volume18 µL
Acquisition Rate5 Hz
Dynamic Range+/- 2500 mV
Connection to PCUSB
Measurement ModesHomopolymer mode, protein mode
Output ResultsBeSEC LS1: Mn, Mw, Mz, Mp, Pd, dn/dc, Concentration, Mw distribution
BeSEC LS2: Mn, Mw, Mz, Mp, Pd, dn/dc, Concentration, Mw distribution, RgAnalog OutputsRI, UV and start signals
Solvent CompatibilityAqueous and organic solvents
Wetted PartsPTFE, PEEK, glass, stainless steel
Power SupplyAC 100-240 V, 50-60 Hz, 4.0 A
Dimensions450 × 325 × 157 mm (= 17.7″ × 12.8″ × 6.2″)
Weight11 kg (= 24.2 lbs)
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Technology
Determining Absolute Molecular Weight
with the Light Scattering Detector
In size exclusion chromatography (SEC), separation depends only on the hydrodynamic size of the molecules. Larger molecules are unable to penetrate the pores of the stationary phase and elute earlier, while smaller molecules enter the pores and elute later. The separation mechanism is purely physical, and no chemical or adsorptive interactions occur between the solute and the stationary phase.
Breaking Free from Column Calibration
How the BeSEC Improves SEC/GPC Workflows
Traditional SEC/GPC systems without light scattering detection provide only relative molecular weight
These systems require calibration with a series of polymer standards to create a calibration curve of molecular weight versus retention volume.
Conventional methods that rely on retention volume introduce significant bias
Polymers with similar hydrodynamic size can elute at the same time yet differ greatly in molecular weight due to structural variations. Without light scattering detection, these differences remain hidden, making it impossible for traditional SEC or GPC to accurately distinguish between such samples.
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Applications
Assess PET grade
Determine Lentinan MW