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Control of adsorption and solubility in gradient high-performance liquid chromatography
- Source :
- Chromatographia. 39:557-563
- Publication Year :
- 1994
- Publisher :
- Springer Science and Business Media LLC, 1994.
-
Abstract
- Copolymers from styrene and methyl methacrylate (MMA) were separated by both normal and reversedphase gradient chromatography. Both modes could be performed by sudden-transition gradients where the polymers were injected into a non-solvent whose polarity was either rather low (e.g.,n-heptane) or high (e.g., acetonitrile). Then the solvent strength of the starting eluent was rapidly increased to a given level by addition of dichloromethane. Under properly defined conditions, the sample components still remained on the column. Elution could be triggered off by the steady addition of another non-solvent whose polarity was opposite of that of the starting non-solvent. Thus, the mixture of five copolymers with MMA content ranging from 14 to 84% could be separated on a polar cyanopropyl column by injection inton-heptane and elution through acetonitrile (normal phase mode) and on a RP C18 column by injection into acetonitrile and elution throughn-heptane (reversed-phase mode), provided that in both modes about 30% dichloromethane was added to the starting non-solvent. The elution sequence in the reversed-phase mode was opposite to that in the normal-phase mode, obeying the approved polarity rules of chromatography in both cases.
Details
- ISSN :
- 16121112 and 00095893
- Volume :
- 39
- Database :
- OpenAIRE
- Journal :
- Chromatographia
- Accession number :
- edsair.doi...........61f9b62e4e2f0c45999ea035e9fea637