Skip to Main Content

Waters – Gel Permeation Chromatography

(Located in Saab/ETIC 114)

Gel Permeation Chromatography (GPC) also referred to as Size Exclusion Chromatography (SEC) is a powerful and versatile analytical technique for understanding and predicting polymer performance. It is a mode of liquid chromatography which separates components of a mixture based on size. In GPC/SEC, larger molecules elute from the column first, and smaller molecules elute later. This technique is used for understanding and predicting polymer performance. It is the most convenient technique for characterizing the complete weight distribution of a polymer.

GPC can determine several important parameters:

  • Number average molecular weight
  • Weight average molecular weight
  • Molecular weight distribution
  • polydisperity

GPC is performed on a Waters Alliance 2695 HPLC system with PDA detector and refractive index detector. We use Waters Styragel HR columns 1,3, and 4 for molecular weight determination. This system is run using 100% tetrahydrofuran as the mobile phase at a flow rate of 0.9ml/min. Each sample must be dissolved in 100% tetrahydrofuran for a few hours before analysis at 10 to 20 mg/ml, and filtered through a 0.45 micron nylon or PTFE filter. Polystyrene standards from a molecular weight of 500 to 400K are used to create the calibration curve. Each GPC run takes one hour to complete. There is a 105 sample carousel for automatic injections. Empower 2 is the software system for controlling the separation and analysis. Training takes approximately one hour. Please contact wendy_gavin@uml.edu for any questions, training or service