A Rayleigh light scattering study on mixing states of 2-propanol-water binary mixtures widely used as mobile phase in separation

Citation
Yg. Wu et al., A Rayleigh light scattering study on mixing states of 2-propanol-water binary mixtures widely used as mobile phase in separation, TALANTA, 54(1), 2001, pp. 69-77
Citations number
42
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
TALANTA
ISSN journal
0039-9140 → ACNP
Volume
54
Issue
1
Year of publication
2001
Pages
69 - 77
Database
ISI
SICI code
0039-9140(20010330)54:1<69:ARLSSO>2.0.ZU;2-0
Abstract
Rayleigh light scatterings of 2-propanol-water binary mixtures at 546 nm ha ve been measured by using a conventional fluorophotometer at 25 degreesC. M ean square concentration fluctuations and Kirkwood-Buff parameters of the m ixtures in a range of 2-propanol mole fraction of 0.0 less than or equal to x(2pr) less than or equal to 0.4 (0-75% (v/v)) have been calculated from t he scattering intensities. On the basis of these parameters, it has been co ncluded that at x(2pr) < 0.05 (15% (v/v)) 2-propanol is well solvated by wa ter molecules, and hydrates consisting of one 2-propanol molecule and 20-30 water molecules are formed in the mixtures. However. at 0.05 <less than or equal to> x(2pr) less than or equal to 0.3 (15-65% (v:v)) large clusters m ainly composed of 2-propanol molecules are formed in the mixtures, and thes e clusters are further reduced into small 2-propanol aggregates at x(2pr) g reater than or equal to 0.4. The usage of 2-propanol as organic modifier an d its effects on CE and RPLC separations are also discussed in terms of mic roheterogeneity in the mobile phase. (C) 2001 Elsevier Science B.V. All rig hts reserved.