Booklet explains principles of Triple Detection GPC/SEC

For laboratories involved with characterisation of natural and synthetic polymers, proteins or nanoparticulate materials - Viscotek has published a new 12-page booklet, comprising a series of technical articles to help practitioners of Triple Detection GPC/SEC better understand and use the technology.

Triple Detection GPC/SEC is a well-established technique for the accurate and full characterisation of macromolecules. The technique combines a concentration detector (refractive index or UV-Visible), viscometer and light scattering detector acting in concert, with each detector providing complimentary but different information. In a single experiment, the triple Detection GPC/SEC enables users to obtain molecular weight, molecular size, intrinsic viscosity, conformation, structure, branching, aggregation and copolymer data from their sample.

The first article discusses concentration detectors and in particular the most commonly used refractive index (RI) technique. The article provides a background to the theory of RI detectors and discusses the reasons for choosing either batch or chromatographic methods of calibration. Other techniques, including UV-Vis, Infrared and Evaporative Light Scattering (ELS) are compared and contrasted to RI for use as a concentration detector for GPC/SEC.

The second article looks at light scattering detectors and in particular provides an authoritative review of the principles of measurement and operation of the Low Angle Light Scattering (LALS) detector. The article demonstrates that by measuring at a very low angle - LALS avoids the complexity, required assumptions and angular correction errors inherent in other light scattering detection techniques.

The third article explores the principles of measurement and operation of the differential Viscometer detector. Useful background information is provided on differential viscometer design, theory of operation and measurement as well as discussing applications where the technique allows GPC/SEC to provide valuable structural data.

The booklet concludes that no single or dual GPC/SEC detector combination can easily measure the range of data (molecular weight, molecular size, intrinsic viscosity, conformation, structure, branching, aggregation, copolymer structure) provided by RI, LALS and Viscometer detectors working in combination.

Malvern Instruments acquired Viscotek in January 2008.