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Capillary electrochromatographyFrame, Lesley A. January 2002 (has links)
No description available.
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Screening of HETP test conditions and resin storage solutions for HICRonnerfors, Lise-Lotte January 2023 (has links)
Hydrophobic interaction chromatography (HIC) is a common purification method for biological drug substances. For continuous monitoring the quality of the purification, a column performance test is carried out to test the packing of the resin. The packing integrity is commonly tested between runs by measuring the Hight Equivalent to a Theoretical Plate (HETP) by injecting a small volume of a tracer solution (spike) that gives a change in conductivity. The column performance test provides useful information regarding the packing quality that could be used for troubleshooting before a purification is performed since a well packed gel is essential for an effective purification. During this thesis project a screening of suitable test conditions for a HETP test for a HIC column was performed. The developed HETP test were then investigated if it could be combined with the storage of the resin or if the packing is affected by the test conditions. Factors such as spike volume, flow rate and the concentration of the elute and spike solution, were considered. 0.1 M NaOH elute and 0.15 M NaCl as spike solution gave the best result based on HETP and the asymmetry of the conductivity peak. A test purification with the new HETP test conditions compared with the old method were then carried out to verify that the quality of the purification is not affected. The purification showed promising result and implementation of a more convenient storage solution and HETP test would be possible without changing the product quality.
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Estudo do papel da Bacia Amazônica na emissão/absorção de dióxido de carbono durante o ano de 2010 / Study of the role of the Amazon Basin in emission/absorption of carbon dioxide during the year 2010DOMINGUES, LUCAS G. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:35:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:18Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Estudo do papel da Bacia Amazônica na emissão/absorção de dióxido de carbono durante o ano de 2010 / Study of the role of the Amazon Basin in emission/absorption of carbon dioxide during the year 2010DOMINGUES, LUCAS G. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:35:21Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:06:18Z (GMT). No. of bitstreams: 0 / A Amazônia armazena em sua floresta na ordem de 95 a 120 PgC de biomassa viva e mais 160 PgC no solo, que podem ser rapidamente liberados para a atmosfera por meio da queima de biomassa e, também, pela mudança do uso da terra. Este estudo foi desenvolvido com o objetivo de elucidar a contribuição da Bacia Amazônica nas emissões de carbono no ano de 2010. A quantificação do CO2 foi realizada por meio da coleta do ar atmosférico utilizando aviões de pequeno porte que descreveram um perfil vertical em quatro locais, estrategicamente posicionado na Bacia Amazônica, e utilizando sistemas semiautomáticos de coleta de ar em 17 ou 12 altitudes diferentes. O Fluxo de emissão/absorção foi calculado pelo método de integração de coluna, que consiste na determinação da concentração de CO2 no perfil vertical, subtraído da concentração de entrada no continente, levando-se em conta o tempo que a massa de ar despende entre a costa e o local de amostragem. Para a determinação da concentração de entrada, foram utilizadas as concentrações medidas pela NOAA nas Ilhas de Ascencion e Barbados e, como traçador de massas de ar, o SF6. Foi encontrado um caráter emissor da Amazônia em território brasileiro para o ano de 2010, em torno de 0,41 PgC, considerando a média ponderada das quatro regiões estudadas, sendo a queima de biomassa a principal responsável. Para a determinação da emissão proveniente da queima de biomassa foi utilizado o CO, como traçador, e a razão CO:CO2. Apesar de possuir um perfil emissor neste ano anormalmente seco, foi possível observar um caráter sumidor de carbono. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Fractionation of natural organic matter (NOM) in water using prepared porous silica based materials as size exclusion (SEC)/GEL permeation chromatography (GPC) stationary phasesBopape, Dineo Anna 06 1900 (has links)
Natural organic matter (NOM) is a diverse blend of decomposed animal and plant material
found in different natural water sources. Due to its large and complex structure, NOM is
difficult to both remove and characterize in water. Therefore, there is a need to separate
NOM into its components before it can be characterized. The aim of this project was to
fractionate NOM through a novel size exclusion chromatography (SEC) composite (poly
(styrene-divinyl benzene) (PS-DVB) and Polysilsesquioxane (PSQ)) packed column. Raw
and final water samples from Mid-Vaal (MV), Olifantspoort (LO), Mtwalume (MT) and
Preekstoel (P) were investigated. Poly (styrene-divinyl benzene) (PS-DVB) and
polysilsesquioxane were both synthesized and optimized at various temperatures,
compositions and time periods. An end-capping material such as hexamethyldisilizane
(HMDS) was added on the PSQ to prevent active silanol groups on the polysilsesquioxane
(PSQ) from reacting with active sites of NOM (our analyte). The E-PSQ (end-capped PSQ)
and PS-DVB materials were packed in eight different SPE cartridges first, before the
materials could be packed in the SEC column. This packing was done to check for the best mass composition of the E-PSQ and PS-DVB. From the obtained SPE results, both the EPSQ
and PS-DVB were packed in one SEC/GPC column at a ratio of 1:1 in order to form
the composite hybrid material. The packed SEC column was connected to an HPLC
instrument and various column efficiency tests were evaluated. The results for the test of
interactions with acidic compounds implied that the column can be used for the acidic
analytes such as those forming NOM composition (humic acids, fulvic acids) and the
column had minimum silanol groups. For hydrophobic interactions the stationary phase
strength was different to that of the commercial columns and it could selectively elute
molecules based on their different masses. The steric selectivity test showed that the
stationary phase could separate and distinguish between molecules with similar
hydrophobicity and structure but different shapes (o-terphenyl and triphenylene). The
Hydrogen bonding capacity (HBC) test showed that the column had minimum silanol
groups and the end-capping was successful on the E-PSQ.
After fractionation of all the water samples, the MT raw showed NOM peaks around 1.8
mins, 3.4 mins and 5.3, and the final showed NOM peaks around 1.8 mins and 5.5 mins.
The Mid-Vaal (MV) raw and final samples shows NOM peaks at around 1.8 mins and 6
mins. The Preekstoel (P) final water had one NOM peak at around 1.8 mins and raw
samples had two NOM peaks around 1.8 mins and 6 mins. / Chemistry / M. Sc. (Chemistry)
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