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Gas chromatographic analysis of some lower molecular weight amines in milk and the relationship of these amines to feed [sic] flavorsMehta, Rajen Sumatilal January 2010 (has links)
Digitized by Kansas Correctional Industries
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An irreversible dissociation of the histone H3-H4 tetramerLewis, Ramilla O January 2011 (has links)
Typescript. / Digitized by Kansas Correctional Industries
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The elucidation of retention behaviour of molecular interactions on bonded phases in reversed phase liquid chromatographyKayillo, Sindy, University of Western Sydney, College of Science, Technology and Environment, School of Science, Food and Horticulture January 2005 (has links)
Separations depend on the molecular interactions occurring on retentive surfaces. Much time and effort is paid in the design and manufacture of chromatographic surfaces that enhance separation capability. This thesis explores some of the design concepts currently available in the market place, and while doing so, investigates the mode of retention on a range of solute species. The information gained from the investigation of the retention and thermodynamic retention behaviour of stationary phases, along with molecular modelling carried out on their stationary phase ligand conformation assists in the design of stationary phase materials that enhance separations. Results from this study indicate that the aromatic functionality on the Synergi-polar-RP column may be diminished, due to the orientation of the phenyl ring on the stationary phase surface. / Doctor of Philosophy (PhD)
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Optimization studies in preparative chromatography of biomoleculesRamanan, Sundar 14 December 2000 (has links)
Optimization of preparative nonlinear chromatography was carried out for
the first time for a biomolecule mixture. Conventional wisdom on optimization,
which roots from analytical chromatography, dictates optimizing resolution in an
analytical column and obtaining similar separation in a large column for isolation.
Such a method of optimization significantly under uses the capacity of the column
and consumes large quantities of mobile phase. Hence, in preparative
chromatography, the objective function is productivity, a measure of compromise
between the amount of feed that can be loaded on to the column and time. Here,
we report results from optimization studies carried out on a closely related binary
peptide mixture on an analytical reversed-phase column. The goal is to optimize
productivity under various chromatographic modes nonlinear isocratic elution,
gradient elution, stepwise elution and displacement chromatography. In each
mode, feed mixtures at highest possible concentration (limited by solubility), for
increasing feed volumes was used. Productivity was monitored for increasing feed
volumes, and loading was stopped as it went through a maximum. However, in
some cases, solubility limitations from one of the feed components prevented
further increase in loading. Even with this constraint, high productivities
(5-10 g product/L stationary phase-h) were achieved. Separate experiments
were carried out to measure the adsorption isotherms of these peptides over the
range permitted by solubility.
Separations under nonlinear chromatographic conditions were applied to
isolate commercially significant two microcystins (microcystin LR and microcystin
LA) from a cyanobacterial process waste. Milligram-level loading of microcystins
was obtained on a solid-phase extraction cartridge packed with 0.5 g of C������
stationary phase. The separations were first carried out on an analytical column
and then scaled-up to a preparative column.
We also report simple and economical process to purify phycocyanins and
allophycocyanins from a cyanobactenal process waste stream for two kinds of
applications food colorant and biomedical marker. A detailed design for the large-scale
production of biliproteins for both applications is also presented. Economic
evaluation of the process resulted in comparable costs with the current market price
for food-grade product and substantially lower cost for the biomedical grade
product. / Graduation date: 2001
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Preparative purification of chemotactic peptides by gradient elution in reversed-phase chromatographyKim, Billy 22 May 1997 (has links)
Gradient elution chromatography is frequently used for the preparative separation
of peptides and proteins. Separations at high loadings are often avoided because peaks
become asymmetrical and saturate the detector. However, non-linear interactions which
become important at high loadings may actually improve the separation with greater
concentrations of the product being extracted. In this study, the separation of a mixture
of two chemotactic peptides N-formyl-met-phe (X~phe) and N-formyl-met-trp (X~trp)
was considered using reversed-phase (RP) chromatography. These runs were limited by
the solubility of the peptides. The effects of solubility and feed conditions on the
chromatograms were examined. Because of the poor solubility of the peptides in low
organic solvent concentration, runs where feed conditions are different from the column
inlet conditions were examined. Since these two components exhibit low selectivity on
the RP column, separation is difficult. Productivities were obtained and compared for the
preparative purification of these compounds using isocratic, stepwise and gradient
elution with acetonitrile/buffer and methanol/water mobile phase conditions. Selectivity
reversal was present in methanol/water conditions. Selectivity reversal implies that the
order of retention of the feed compound changes as the mobile phase composition varies.
Curved gradient shapes were used in an attempt to improve the separation under
selectivity reversal limitation. Using a combination of solubility methods and non-linear
interactions at high loadings, simultaneous concentration and purification was achieved. / Graduation date: 1998
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Effect of identity and number of chiral microemulsion components in chiral microemulsion electrokinetic chromatography /Kahle, Kimberly Ann. Foley, Joe Preston, January 2007 (has links)
Thesis (Ph. D.)--Drexel University, 2007. / Includes abstract and vita. Includes bibliographical references (leaves 240-242).
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Protein purification using expanded bed chromatographyRamat, Fabien M. January 2003 (has links)
Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: zirconia; protein purification; anion exchange; chicken egg white; expanded bed chromatography. Includes bibliographical references (p. 83-86).
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CHROMATOGRAPHIC CHARACTERIZATION OF POLYMERIC ADSORBENTSButler, Larry Dean January 1978 (has links)
No description available.
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Diastereoselective transformation of 1,2,4-triols to hydroxy tetrahydrofurans and monosulfonylated derivatives .Gamedze, Makhosazana Primrose. January 2014 (has links)
D. Tech. Chemistry / The avocado oil contains compounds with potency against ailments caused by some bacteria, fungi, viruses as well as some insects and parasites. Present in the oil are long aliphatic hydrocarbons (acetogenins) documented to have a wide range of biological activities such as anticancer, antibacterial, antifungal, insecticidal and nematocidal properties and as a result the oil is fast gaining popularity amongst consumers. The demand and popularity of the oil makes it a target for contamination and adulteration of with cheaper oils. Chromatographic techniques such as Gas chromatography (GC) and High performance liquid chromatography (HPLC) are the frequently used methods of oil analysis to safe guard against adulteration. Derivatization of acetogenins uniquely found in avocado oil would provide derivatives which can be used as markers for authentication of the oil, an alternative method to fatty acid methyl ester analysis.
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Computer assisted investigations of chromatographic processesWright, Norman Alan January 1981 (has links)
No description available.
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