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An improved method to validate the relative humidity generation in sorption balances

Wadsö, Lars LU ; Anderberg, Anders LU ; Åslund, Ingrid LU and Söderman, Olle LU (2009) In European Journal of Pharmaceutics and Biopharmaceutics 72. p.99-104
Abstract
Sorption balances are instruments in which samples are weighed as they are exposed to a programmed relative humidity (RH). Such instruments are used to measure sorption isotherms and to study solid-vapour interaction. There are different methods to validate the performance of the RH generation in such instruments by charging them with saturated salt solutions and ramping/stepping the RH past the deliquescence RH of the salts. In this paper an improved approach to perform validation is presented where the RH is kept stepwise constant at a quasi-randomly chosen set of RH-values above and below the deliquescence RH. From the rates of change of mass as a function of RH it is possible to calculate the RH at which deliquescence takes place. This... (More)
Sorption balances are instruments in which samples are weighed as they are exposed to a programmed relative humidity (RH). Such instruments are used to measure sorption isotherms and to study solid-vapour interaction. There are different methods to validate the performance of the RH generation in such instruments by charging them with saturated salt solutions and ramping/stepping the RH past the deliquescence RH of the salts. In this paper an improved approach to perform validation is presented where the RH is kept stepwise constant at a quasi-randomly chosen set of RH-values above and below the deliquescence RH. From the rates of change of mass as a function of RH it is possible to calculate the RH at which deliquescence takes place. This alternative method gives similar results as the slow ramp method, but is less sensitive to disturbances and less time consuming. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
European Journal of Pharmaceutics and Biopharmaceutics
volume
72
pages
99 - 104
publisher
Elsevier
external identifiers
  • wos:000265777400013
  • scopus:63149122292
ISSN
0939-6411
DOI
10.1016/j.ejpb.2008.10.013
language
English
LU publication?
yes
id
aefafc59-4353-412d-b56e-089114a5525e (old id 1266382)
date added to LUP
2008-11-11 16:47:24
date last changed
2017-06-18 03:31:15
@article{aefafc59-4353-412d-b56e-089114a5525e,
  abstract     = {Sorption balances are instruments in which samples are weighed as they are exposed to a programmed relative humidity (RH). Such instruments are used to measure sorption isotherms and to study solid-vapour interaction. There are different methods to validate the performance of the RH generation in such instruments by charging them with saturated salt solutions and ramping/stepping the RH past the deliquescence RH of the salts. In this paper an improved approach to perform validation is presented where the RH is kept stepwise constant at a quasi-randomly chosen set of RH-values above and below the deliquescence RH. From the rates of change of mass as a function of RH it is possible to calculate the RH at which deliquescence takes place. This alternative method gives similar results as the slow ramp method, but is less sensitive to disturbances and less time consuming.},
  author       = {Wadsö, Lars and Anderberg, Anders and Åslund, Ingrid and Söderman, Olle},
  issn         = {0939-6411},
  language     = {eng},
  pages        = {99--104},
  publisher    = {Elsevier},
  series       = {European Journal of Pharmaceutics and Biopharmaceutics},
  title        = {An improved method to validate the relative humidity generation in sorption balances},
  url          = {http://dx.doi.org/10.1016/j.ejpb.2008.10.013},
  volume       = {72},
  year         = {2009},
}