This is our secondary GPC, typically used for polymers which are insoluble in THF, or when the specific refractive index increment (dn/dc) for the analyte in THF is small. It provides data from two complementary detectors simultaneously: 1) differential refractive index at 950 nm (DRI, Waters 410), and 2) two-angle static light scattering at 683 nm (Precision Detectors PD2020, installed inside the Waters 410 box). Both the Precision Detectors Discovery32 software package, and home-written analysis software, are employed for the construction of molecular weight distributions. The toluene mobile phase is delivered by a Waters 590 pump, with a Rheodyne 7725i sample injector. Separation is effected by two Polymer Laboratories 30 cm PLGel Mixed-C columns kept at 40°C by a Waters Column Heater Module and Waters Temperature Control Module II.