Browse DORAS
Browse Theses
Latest Additions
Creative Commons License
Except where otherwise noted, content on this site is licensed for use under a:

Paired emitter-detector diode detection with dual wavelength monitoring for enhanced sensitivity to transition metals in ion chromatography with post-column reaction

O'Toole, Martina and Barron, Leon and Shepherd, Roderick and Nesterenko, Pavel and Paull, Brett and Diamond, Dermot (2009) Paired emitter-detector diode detection with dual wavelength monitoring for enhanced sensitivity to transition metals in ion chromatography with post-column reaction. The Analyst, 134 (1). pp. 124-130. ISSN 1364-5528

Full text available as:

PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader


The combination of post-column derivatisation and visible detection are regularly employed in ion chromatography (IC) to detect poorly absorbing species. Although this mode is often highly sensitive, one disadvantage is the increase in repeating baseline artifacts associated with out-of-sync pumping systems. The work presented here will demonstrate the use of a second generation design paired emitter-detector diode (PEDD-II) detection mode offering enhanced sensitivity to transition metals in IC by markedly reducing this problem and also by improving signal noise. First generation designs demonstrated the use of a single integrated PEDD detector cell as a simple, small (15 x 5 mm), highly sensitive, low cost photometric detector for the detection of metals in ion chromatography (IC). The basic principle of this detection mode lies in the employment of two linear light emitting diodes (LEDs), one operating in normal mode as a light source and the other in reverse bias serving as a light detector. The second generation PEDD-II design showed increased sensitivity for Mn(II)- and Co(II)-2-(pyridylazo) resorcinol (PAR) complexes as a result of two simultaneously acquiring detection cells - one analytical PEDD cell and one reference PEDD cell. Therefore, the PEDD-II employs two wavelengths whereby one monitors the analyte reaction product and the second monitors a wavelength close to the isosbestic point. The optimum LED wavelength to be used for the analytical cell was investigated to maximise peak response. The fabrication process for both the analytical and reference PEDD cells was validated by determining the reproducibility of detectors within a batch. The reproducibility and sensitivity of the PEDD-II detector was then investigated using signals obtained from both intra- and inter-day chromatograms.

Item Type:Article (Published)
Subjects:Physical Sciences > Analytical chemistry
Physical Sciences > Detectors
Physical Sciences > Chemistry
DCU Faculties and Centres:DCU Faculties and Schools > Faculty of Science and Health > School of Chemical Sciences
Research Initiatives and Centres > Adaptive Information Cluster (AIC)
Research Initiatives and Centres > National Centre for Sensor Research (NCSR)
Publisher:Royal Society of Chemistry
Official URL:
Copyright Information:© The Royal Society of Chemistry 2009
Use License:This item is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 3.0 License. View License
Funders:Science Foundation Ireland
ID Code:2977
Deposited On:31 Mar 2009 12:25 by martina o'toole. Last Modified 05 Nov 2009 04:02

Download statistics

Archive Staff Only: edit this record