A Oiss{!y'tation $uhm'itted in fulfilment of the r~;~airements, for' the degree of f·1aster· oi~'j Science at the University of the ~titwatersrand ' Juhanoasbul"g January 1991 / An attempt was made to separate ribosomal subunits by gel filtl'ation on Trisacryl GF2000 and Sepharose 4B. Trisacryl GP~2000,a sYllthet'ic gol, , separated rat .ljver rlbosonal subunits orl 'f~'135,em column with a resolution of ""Or3, resulting 'in <'1" 60 rJ impm''ity 'of each of the \~ subunits. subunits" were not resolved. Sepharose 4131 an agarose based gol, separated " the subunits by adsorpttcn chromatography rathr.r than 'i>.V () Q ':) At 4°C, the 405 .subunf ts were eluted with a kd () ruO,:~9( but the GOrf' $ubud"its adsorbed to th~.'g,~Jl and were eluted I; /) when the temperature of "the column was increas~d to 250C..3SoC. (' ,. ('-. This edsorpt ion phenonenon seems to b{~ tl propert~ of a 11 agllrose -: \') ~\:; based gels studied here, includ'ing Sepharose 2.B and .seph'ato~eoBt arid is exc 1us iva to !,mamm'i'lan r ibosOIntrt subuni ts • Anal,ys1S 0'(" the , u subunits by in vitro r14C]polypheny1alanine sy'nthes'is showed OCI " ,,'c. /\ I 7', " diff'erence 'in the act lvtt ies of dbosoma'J ~ubunH~ p~epdrf#d by ;/'/ ' grndient centrifugation or by 5epharos,e cni"OmatogNPPY;' Analy~ii ~~of " (~ (( the subunits by ~crylamidec'ugarose coU)po5it~) gs1s resulted ,in the '/ resolution ,.:n"f subunits isolated fr'oill lower organisms in o II non-denaturlnq !Jcl systems and SI,lbut1its from m«mm~nan'tissue in II /'\';1 Ga'! f'iltrat'ion does tyffer a 5t!i:l;~'ble metrKld'¥or the pr~p;n~¥tiol1of <::) . I \) \\ I) ribosoma 1 'subunits I but only' if 'the act~orption JH'OrJ&~"t'Jo,s of ,) (,) ':' o ,1) ,{

by Wong Dart-man. / Bibliography: leaves 107-114 / Thesis (M.Phil.)--Chinese University of Hong Kong, 1982

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 129-147).

<p> The work of this study is divided into two parts. Part I reports on the development of a dedicated minicomputer, data acquisition, and reduction system for GPC. The hardware, software, and operating performance of the system is discussed in some detail.</p> <p> Part II, reports on an experimental study design to determine whether axial dispersion corrections are universal in the sense of being independent of polymer composition. Results for poly(vinyl-chloride), polystyrene, polybutadiene, and poly(methy-methacrylate) are discussed.</p> / Thesis / Master of Engineering (MEngr)

Crosslinked poly-4-vinylpyridine (XPVP) has not previously been used as a size exclusion chromatographic packing material. This material appears attractive for the analysis of nitrogen containing polymers because of its basic nitrogen functionality, and desirable physical properties. Its use as such is investigated with probe compounds in several different mobile phases. Various methods of separation of the XPVP material by particle size are employed. In addition, four column packing techniques were examined. / Master of Science

The purpose of this investigation was to propose a method to determine the composition distribution, on one hand, and the molecular weight distribution, on the other hand, for block copolymers. The technique selected to determine this kind of information was Gel Permeation Chromatography, because, since its introduction in 1964, it has become the most powerful tool for the rapid characterization of homopolymers. The proposed method is introduced by considering a dual-approach: composition distribution (calibration of detectors with composition) and molecular weight distribution (calibration of columns with composition). The absence of heterointeractions in block copolymers led to a behavior which depends solely on the elution behavior of the corresponding homopolymers. Finally, it is concluded that all this meaningful information about block copolymers can be perfectly obtained when adequate raw Gel Permeation Chromatography data handling, taking into account composition, is done. / M.S.

Dilute solution properties of three difficult-to-analyze macromolecular systems were investigated and clarified. Two were notorious for having highly time-in-solution dependent properties, nitrocellulose and lignin, while the third was an ideal model branched methacrylate polymer with which to examine unanswered questions in polymer hydrodynamic behavior. Gel permeation chromatography with a differential viscosity detector (GPC/DV) was employed to study the dilute solution properties of various polymers, specifically their absolute molecular weight distributions and hydrodynamic behavior. The study was divided into three parts. The first part focused on the time dependent change in molecular weight of nitrocellulose. Samples having 12.58% and 13.5% levels of nitration were investigated in THF and EtOAc. GPC/DV, LALLS, FT-IR and intrinsic viscosity experiments revealed that the materials existed as associated molecules in solution which decreased in molecular weight upon storage to extents dependent on the solvent. The second part was an examination of the hydrodynamic behavior of hydroxypropylated lignins using GPC/LALLS/DV and VPO. These materials were found to increase in molecular weight upon storage in solution due to association. Special precautions had to be taken in running experiments to obtain the correct molecular weights and molecular weight distributions. The last part involved a fundamental study of PMMA-g-PMMA's having similar molecular weights but containing different levels of branching. Variable temperature GPC/LALLS/DV was employed to obtain molecular weight distributions, branching parameters, average chain dimensions and information on the hydrodynamic behavior of these branched systems. Samples containing up to 40% of long chain branching were found to obey the universal calibration analytic scheme of GPC. / Ph. D.

<p><em>Size exclusion chromatography</em> (SEC) was applied for purification of psychoactive biomolecules from plants. These molecules are in the same molecular weight range, but do not necessarily share other chemical properties, that makes the SEC technique efficient. By applying SEC as a first purification step much of the co-extractives from the plants can easily be removed. Large amounts of target substance can be obtained with little effort if the system is automated. Combining SEC with a second purification step, consisting of normal phase chromatography, provides high purity of the target substance.</p><p>Both known and unknown psychoactive biomolecules can easily be purified using the purification method developed in this Master's Thesis. Purifications that previously required long time and much "hands-on" can be completed much faster and with less manual work.</p><p>The method developed was tested on cannabis, coffee and 'Spice' with good results.</p>

Size exclusion chromatography (SEC) was applied for purification of psychoactive biomolecules from plants. These molecules are in the same molecular weight range, but do not necessarily share other chemical properties, that makes the SEC technique efficient. By applying SEC as a first purification step much of the co-extractives from the plants can easily be removed. Large amounts of target substance can be obtained with little effort if the system is automated. Combining SEC with a second purification step, consisting of normal phase chromatography, provides high purity of the target substance. Both known and unknown psychoactive biomolecules can easily be purified using the purification method developed in this Master's Thesis. Purifications that previously required long time and much "hands-on" can be completed much faster and with less manual work. The method developed was tested on cannabis, coffee and 'Spice' with good results.

Thesis (M.S.)--Mississippi State University. Department of Chemistry. / Title from title screen. Includes bibliographical references.