Online Quasi-Elastic Light Scattering from your HPLC.

The WyattQELS™ (Quasi-Elastic-Light-Scattering) is a compact, add-on instrument that can be connected to the DAWN® or miniDAWN™ in order to determine particle sizes and their distributions. The WyattQELS™ instrument contains a real time digital correlator. The correlator measures the autocorrelation function of the intensity signal from any one angle of the DAWN®  or from the 90 degree location of the miniDAWN™. The correlator then calculates the hydrodynamic radius at each elution time in order to provide hydrodynamic radii over an entire chromatographic peak.


What makes the WyattQELS™ unique:

Unlike many other dynamic light scattering instruments, the WyattQELS™ detector, when interfaced to the DAWN® , allows one to measure correlation as a function of angle. Particles larger than 150nm may scatter relatively little light at 90 degrees because of intra-particle interface or "Mie scattering". This effect may cause significant distortion in computer particles size distribution for some kinds of polydisperse samples. Since the WyattQELS™ optical fiber can be moved easily to any one of the 18 DAWN® angles, the measurements can be optimized for the best results for particles that are very large. With most other instruments, which only make measurements at 90 degrees, if large particles are present, the signals may be low or lost altogether. But with the WyattQELS™ you can always move the optical fiber to a lower or a higher angle.

WyattQELS™ Features include:

  • Multiple Tau correlation design with a fixed range of channel from 480 nsec to ~1 hour (real-time).
  • No sample time optimization required!
  • A total of 264 channels with input data format of 5 bit for the first 16 channels, the the sample time doubles every 8 channels and the data width is incremented 1 bit for every set of channels. No pre-scaling required.

Do you want more information? We would be delighted to hear from you!