This document introduces the response characteristics of RI and ELSD, and uses a series of polystyrene standards for research. The results show that the ELSD has higher sensitivity, but the relative peak areas of the two are very similar. In addition, the ELSD performs better at low molecular weights.
This document investigates the response characteristics of detectors used in Gel Permeation Chromatography (GPC) as a function of molecular weight. It compares results from a Refractive Index (RI) detector and the Varian Evaporative Light Scattering Detector (ELSD) using narrow polydispersity polystyrene standards. The study found that while the ELSD delivers greater sensitivity, the relative peak areas for both detectors indicate very similar results, showing a response independent of molecular weight over the range of 1,000 to 1,000,000.
| Columns | 2 x PLgel 5 um MIXED-C, 300 x 7.5 mm |
|---|---|
| Eluent | THF |
| Flow Rate | 1.0 mL/min |
| Neb Temperature | 40 °C |
| Evap Temperature | 90 °C |
| Gas Flow | 1.0 SLM |
Yes, the Varian ELSD delivers greater sensitivity, although the relative peak areas for both detectors indicate very similar results.
Yes, the response was independent of molecular weight over the range 1,000 - 1,000,000.
The Varian ELSD has the potential to evaporate more volatile, lower molecular weight compounds, resulting in smaller peaks being detected for these probes.