Page 123 - Illustrated Pocket Dictionary of Chromatography

122 LOW-ANGLE LASER LIGHT SCATTERING DETECTOR (LALLS)

This component of the HPLC injector valve contains the sample that is presented
by the syringe. These are 20-mL and 10-mL stainless steel loops. Loops are also con-
structed from PEEK.

low-angle laser light scattering detector (LALLS) Measures
the light scattered from a high-intensity laser source by macromole-
cules in the effluent. Through a plot of CK/Rf versus concentration an
intercept of 1/MW is obtained, where C is the solute concentration, K
is the function of an optical parameter of the macromolecule, and Rf
is the Rayleigh scattering at low angle f.

low-pressure gradient pump Forms a gradient through the use
of solenoids connected to each reservoir and a mixing block that is
positioned before the pump. In this case only one high-pressure pump
is needed and therefore is advantageous over a high-pressure gradi-
ent pump from a cost consideration. The major disadvantage is that
the dwell volume is considerable in these types of systems.