Universal Liquid Chromatography Detector
All liquid chromatographic (LC) detectors used for quantitative measurements exhibit response bias in some way. For example, the ubiquitous UV/Vis detector which is the industry standard will only respond to analytes with chromophores which absorb in the 190-600 nm range, and sensitivity can also be impacted by the wavelength selected for the analysis and the mobile phase properties. Additionally, UV relative response factors (RRF) for analytes within the same sample can often be quite different - requiring the synthesis of authentic reference standards and the determination of correction factors (1/RRF) to allow quantitative assay. Equally, there are known limitations with detectors utilizing mobile phase nebulization towards semi-volatile analytes and linearity of response (e.g. ELSD, CAD, MS). The only LC detector currently recognized as universally responsive, the refractive index (RI) detector, is incompatible with the gradient chromatography typically required for pharmaceutical analysis and is relatively insensitive. All other common detectors also have limitations regarding quantitation.
This ETC project team has several decades of collective experience of working with liquid chromatography and have used or evaluated all current commercially available detectors for their ‘universal’ application with LC. While some detectors show promise, the project team feel that the requirement for unbiased detector response allowing true quantitation irrespective of analyte properties is currently unavailable. The aim of this RFI is to solicit understanding of what technologies are currently being developed within academia and/or industry with a view to either (i) partnering with the group to evaluate the instrument (ii) provide cross-industry insight into any current design or (iii) initiate the development of a new technology which meets the groups requirements.