Viscotek, a Malvern company, has developed a photodiode array (PDA) detector for its TDAmax gel permeation chromatography/size exclusion chromatography (GPC/SEC) system.
The detector provides a flexible tool for the analysis of both polymers and biological macromolecules.
The PDA is suitable for the analysis of blends used to produce high-performance polymers, and the product streams from complex co-polymerisation reactions.
Its many applications in the life sciences include identifying protein conjugates and complexes, aggregation and stability and determining concentration ratios.
The TDAmax is a GPC/SEC system with an integrated triple or tetra detector array.
By capturing absorption spectra across the UV-vis wavelength range, the PDA detector provides a fingerprint of each 'time slice' of the sample as it elutes from the column.
Measurement times are just 30 to 40 minutes.
UV detection is used routinely to identify protein and polymer species as they elute, and can differentiate between components when other detection methods cannot.
However, a conventional system measures at a single wavelength.
In contrast, the PDA detector captures data across the range 190 to 500nm, allowing users to select wavelengths of interest after the analysis has been carried out.
The PDA also has particular application in the field of smart material research, since unique electrical, thermal or photochromic properties often correlate directly with UV absorption characteristics.
The information it gives can be used in both product and process development.
The UV cell of the PDA sits in the temperature-controlled zone of the TDAmax, operating at up to 80C.
Viscotek's Omnisec software package allows data to be displayed as information-rich 3-D images to simplify interpretation.
