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Assessment of the complementarity of temperature and flow-rate for response normalisation of aerosol-based detectors


Khandagale, MM and Hilder, EF and Shellie, RA and Haddad, PR, Assessment of the complementarity of temperature and flow-rate for response normalisation of aerosol-based detectors, Journal of Chromatography A, 1356 pp. 180-187. ISSN 0021-9673 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 Elsevier

DOI: doi:10.1016/j.chroma.2014.06.055


The solvent dependency of the detection response is a major limitation of corona-charged aerosol detection (C-CAD). The present study empirically investigates the utility of temperature and flow-rate gradients to overcome solvent gradient limitations of C-CAD. In preliminary flow-injection investigations, it is demonstrated that the response of C-CAD remains relatively unaltered with variations in flow-rate when used with water-rich eluents. Based on these findings two separation approaches were developed and their utility for C-CAD response normalisation was demonstrated using a mixture of eight analytes. In the first approach the use of a solvent gradient is replaced with a temperature gradient performed under isocratic mobile phase conditions. Detection response is further enhanced by mixing a secondary stream of pure acetonitrile with the column effluent, yielding a 3-fold increase in detection response. In the second approach, flow-rate programming is used to improve speed of isocratic-temperature gradient separation. The use of simultaneous variation in flow-rate and column temperature reduced the separation time by 30%, with relatively uniform analyte response. Lastly, an inverse-gradient solvent compensation approach was used to evaluate the response homogeneity and the applicability of the above approaches for quantitative analysis. Good peak area reproducibility (RSD% < 15%) and linearity (R2 > 0.994, on a log-scale) over the sample mass range of 0.1-10μg was achieved. The response deviation across the mixture of eight compounds at seven concentration levels was 6-13% compared to 21-39% when a conventional solvent gradient was applied and this response deviation was comparable to that obtained in the inverse gradient solvent compensation approach. Finally, applicability of these approaches for typical pharmaceutical impurity profiling was demonstrated at a concentration of 5μg/mL (0.1% of the principal compound).

Item Details

Item Type:Refereed Article
Keywords:C-CAD response normalisation, post-column solvent addition, flow rate gradient, temperature gradient separation
Research Division:Chemical Sciences
Research Group:Analytical chemistry
Research Field:Separation science
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the chemical sciences
UTAS Author:Khandagale, MM (Mr Manish Khandagale)
UTAS Author:Hilder, EF (Professor Emily Hilder)
UTAS Author:Shellie, RA (Associate Professor Robert Shellie)
UTAS Author:Haddad, PR (Professor Paul Haddad)
ID Code:96186
Year Published:2014
Web of Science® Times Cited:8
Deposited By:Austn Centre for Research in Separation Science
Deposited On:2014-10-22
Last Modified:2018-03-14

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