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Dynamic pH determination at high pressure of aqueous additive mixtures in contact with dense CO2

Andersson, Martin LU ; Rodriguez-Meizoso, Irene LU ; Turner, Charlotta LU ; Hjort, Klas and Klintberg, Lena (2018) In Journal of Supercritical Fluids 136. p.95-101
Abstract

A system consisting of a high-pressure tolerant microfluidic glass chip, high-speed absorbance imaging, and image processing has been developed to study rapid dynamic events like pH change in a multiphase flow. The system gives both kinetic and quantitative equilibrated information. By tracking the interactions of aqueous additive mixtures and liquid CO2, at 80 bar and 24 °C, under flow, measurement at a given P, T condition is done in 0.25 s. The acidification rate to steady state was found to be mass transport limited, occurring in less than 1 s. For 30 mM of the additives ammonium acetate and ammonium formate, equilibrium pH of 4.5 and 4.1, respectively, was seen. These additives are of key importance in common mobile... (More)

A system consisting of a high-pressure tolerant microfluidic glass chip, high-speed absorbance imaging, and image processing has been developed to study rapid dynamic events like pH change in a multiphase flow. The system gives both kinetic and quantitative equilibrated information. By tracking the interactions of aqueous additive mixtures and liquid CO2, at 80 bar and 24 °C, under flow, measurement at a given P, T condition is done in 0.25 s. The acidification rate to steady state was found to be mass transport limited, occurring in less than 1 s. For 30 mM of the additives ammonium acetate and ammonium formate, equilibrium pH of 4.5 and 4.1, respectively, was seen. These additives are of key importance in common mobile phases used in SFC.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Additive salts, Dense CO, High-pressure microfluidics, Image analysis, Multiphase flow, Supercritical fluid chromatography
in
Journal of Supercritical Fluids
volume
136
pages
7 pages
publisher
Elsevier
external identifiers
  • scopus:85042376176
ISSN
0896-8446
DOI
10.1016/j.supflu.2018.02.012
language
English
LU publication?
yes
id
3f585d89-1767-4f88-91d0-9d8fd29f1c93
date added to LUP
2018-03-05 08:02:17
date last changed
2018-05-29 09:42:50
@article{3f585d89-1767-4f88-91d0-9d8fd29f1c93,
  abstract     = {<p>A system consisting of a high-pressure tolerant microfluidic glass chip, high-speed absorbance imaging, and image processing has been developed to study rapid dynamic events like pH change in a multiphase flow. The system gives both kinetic and quantitative equilibrated information. By tracking the interactions of aqueous additive mixtures and liquid CO<sub>2</sub>, at 80 bar and 24 °C, under flow, measurement at a given P, T condition is done in 0.25 s. The acidification rate to steady state was found to be mass transport limited, occurring in less than 1 s. For 30 mM of the additives ammonium acetate and ammonium formate, equilibrium pH of 4.5 and 4.1, respectively, was seen. These additives are of key importance in common mobile phases used in SFC.</p>},
  author       = {Andersson, Martin and Rodriguez-Meizoso, Irene and Turner, Charlotta and Hjort, Klas and Klintberg, Lena},
  issn         = {0896-8446},
  keyword      = {Additive salts,Dense CO,High-pressure microfluidics,Image analysis,Multiphase flow,Supercritical fluid chromatography},
  language     = {eng},
  month        = {06},
  pages        = {95--101},
  publisher    = {Elsevier},
  series       = {Journal of Supercritical Fluids},
  title        = {Dynamic pH determination at high pressure of aqueous additive mixtures in contact with dense CO<sub>2</sub>},
  url          = {http://dx.doi.org/10.1016/j.supflu.2018.02.012},
  volume       = {136},
  year         = {2018},
}