The dependence of the apparent pK of ion exchange celluloses of ionic strength
Diethylaminoethyl cellulose was titrated with acid and base in various concentrations of NaCl. The pK values were determined from titration curves using a graphical technique. Two titratable groups were observed from the acid titration curve, a major and a minor group. The minor group, which represe...
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| Format: | Others |
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BYU ScholarsArchive
1977
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| Online Access: | https://scholarsarchive.byu.edu/etd/8212 https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=9212&context=etd |
| Summary: | Diethylaminoethyl cellulose was titrated with acid and base in various concentrations of NaCl. The pK values were determined from titration curves using a graphical technique. Two titratable groups were observed from the acid titration curve, a major and a minor group. The minor group, which represented 20% of the acid titration, was barely detectable in the base titration curve and had a salt-independent pK of 6.0. The pK of the major group was strongly salt-dependent and was approximately a linear function of log N NaCl. An equilibrium shift caused by the counter ion may explain the salt dependence. Hydrogen bonding may explain the presence of the minor group. The salt dependence of the pK of ion exchange celluloses may explain pH shifts and artifactitious peaks occasionally observed in column chromatography of proteins. |
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