Four mechanisms were considered as possible causes of the loss in resolution for a Dionex CG2 ion chromatography resin: 1) presence of inorganic ions strongly bound to the active sites; 2) adsorption of organic species; 3) physical alterations; and 4) chemical alterations. The instrumental analyses used to gather data were ICP, FT-IR, SEM, solid C-13 NMR and IC. Based on the results, no metal ions are bound to the resin, no organic species are held onto the resin, and no physical change was observable. The cause for the loss of resolution is a strong reduction in the number of active sites in the resin as confirmed by elemental analysis for the sulfur in the sulfonic acid present in the active sites.

No description available.

Waste-to-energy has become an attractive alternative to landfills. One concern in this development is the release of pollutants in the combustion process. The binder enhanced d-RDF pellets satisfy the requirements of environmental acceptance, chemical/biological stability, and being storeable. The acid gas emissions of combusting d-RDF pellets with sulfur-rich coal were analyzed by ion chromatography and decreased when d-RDF pellets were utilized. The results imply the possibility of using d-RDF pellets to substitute for sulfur-rich coal as fuel, and also substantiate the effectiveness of a binder, calcium hydroxide, in decreasing emissions of SOx. In order to perform the analysis of the combustion sample, sampling and sample pretreatment methods prior to the IC analysis and the first derivative detection mode in IC are investigated as well. At least two trapping reagents are necessary for collecting acid gases: one for hydrogen halides, and the other for NOx and SOx. Factors affecting the absorption of acid gases are studied, and the strength of an oxidizing agent is the main factor affecting the collection of NOx and SOx. The absorption preference series of acid gases are determined and the absorption models of acid gases in trapping reagents are derived from the analytical results. To prevent the back-flushing of trapping reagents between impingers when leak-checking, a design for the sampling train is suggested, which can be adopted in sample collections. Several reducing agents are studied for pretreating the sample collected in alkali-permanganate media. Besides the recommendation of the hydrogen peroxide solution in EPA method, methanol and formic acid are worth considering as alternate reducing agents in the pretreatment of alkaline-permanganate media prior to IC analysis. The first derivative conductivity detection mode is developed and used in IC system. It is efficient for the detection and quantification of overlapping peaks as well as being applicable for non-overlapping peaks.

O método cromatográfico de troca iônica, em colunas de resina foi empregado no estudo do enriquecimento isotópico de 10B e H3 10BO3. Em dois sistemas cromatográficos de colunas (S1: seis colunas de acrílico de 1800 mm de comprimento e 70 mm de diâmetro interno; S2: seis colunas de acrílico de 1800 mm de comprimento e 30 mm de diâmetro interno) foi estudado a separação do isótopo 10B, no equilíbrio envolvendo ácido bórico em solução aquosa e íons borato adsorvidos em resina aniônica do tipo amônio quaternário (Dowex 1X8), 100 - 200 \"mesh\". Os sistemas de produção de H3 10BO3 foram avaliados individualmente e em processo cascata, com transferência de 10B entre os dois sistemas. As determinações de B no presente trabalho foram avaliadas por espectrometria de massas com plasma e espetrometria de massas por termoionização. No sistema S1 de colunas após 243 m (135 DBC) de deslocamento foi possível obter um enriquecimento médio, nos últimos 20 cm, de 40 % em átomos de 10B, correspondendo a 2830 mg de H3 10BO3. Essa massa foi transferida (interação) para o sistema S2 de colunas que apresentava, nos últimos 20 cm da banda, enriquecimento médio de 47,8 % em átomos de 10B e essa nova banda cromatográfica foi deslocada por 21,6 m, obtendo-se no último centímetro da banda (1 - 0 cm) da fração enriquecida 82 % em átomos de 10B. O fator de fracionamento (\'alfa\') e a altura equivalente de uma placa teórica dos isótopos estáveis de B (10B e 11B) foi determinado como sendo 1,0245 e 0,30 cm, respectivamente / The chromatographic method of ion exchange resin in columns was used to study the isotopic enrichment of 10B and H3 10BO3. In two column chromatographic systems (S1: six acrylic columns 1800 mm length and 70 mm diameter; S2: six acrylic columns 1800 mm length and 30 mm diameter) was studied 10B isotope separation in equilibrium involving aqueous boric acid and borate ions adsorbed on anionic resin of the quaternary ammonium type (Dowex 1X8) 100-200 \"mesh\". The production systems H3 10BO3 were evaluated individually and in cascade process with 10B transfer between both systems. The measurements of B in this study were evaluated by Inductively Coupled Plasma Mass Spectrometry and Thermal Ionization Mass Spectrometry. In the S1 columns system displacement after 243 m (135 DBC) was possible obtain an medium enrichment in the last 20 cm, of 40 % atoms 10B, corresponding to 2830 mg of H310BO3. This mass was transferred to the S2 column system which have introduced in the last 20 cm of the band medium enrichment of 47,8 atom% 10B and this new band chromatography was displaced 21,6 m, thus obtaining the last centimeter band (1-0 cm) from enriched fraction 82 % atoms 10B. The fractionation factor (\'alfa\') and the Height Equivalent of Theoretical Plate (HETP) of stable isotopes of B (10B and 11B) was determined like being 1,0245 and 0,30 cm, respectively

O método cromatográfico de troca iônica, em colunas de resina foi empregado no estudo do enriquecimento isotópico de 10B e H3 10BO3. Em dois sistemas cromatográficos de colunas (S1: seis colunas de acrílico de 1800 mm de comprimento e 70 mm de diâmetro interno; S2: seis colunas de acrílico de 1800 mm de comprimento e 30 mm de diâmetro interno) foi estudado a separação do isótopo 10B, no equilíbrio envolvendo ácido bórico em solução aquosa e íons borato adsorvidos em resina aniônica do tipo amônio quaternário (Dowex 1X8), 100 - 200 \"mesh\". Os sistemas de produção de H3 10BO3 foram avaliados individualmente e em processo cascata, com transferência de 10B entre os dois sistemas. As determinações de B no presente trabalho foram avaliadas por espectrometria de massas com plasma e espetrometria de massas por termoionização. No sistema S1 de colunas após 243 m (135 DBC) de deslocamento foi possível obter um enriquecimento médio, nos últimos 20 cm, de 40 % em átomos de 10B, correspondendo a 2830 mg de H3 10BO3. Essa massa foi transferida (interação) para o sistema S2 de colunas que apresentava, nos últimos 20 cm da banda, enriquecimento médio de 47,8 % em átomos de 10B e essa nova banda cromatográfica foi deslocada por 21,6 m, obtendo-se no último centímetro da banda (1 - 0 cm) da fração enriquecida 82 % em átomos de 10B. O fator de fracionamento (\'alfa\') e a altura equivalente de uma placa teórica dos isótopos estáveis de B (10B e 11B) foi determinado como sendo 1,0245 e 0,30 cm, respectivamente / The chromatographic method of ion exchange resin in columns was used to study the isotopic enrichment of 10B and H3 10BO3. In two column chromatographic systems (S1: six acrylic columns 1800 mm length and 70 mm diameter; S2: six acrylic columns 1800 mm length and 30 mm diameter) was studied 10B isotope separation in equilibrium involving aqueous boric acid and borate ions adsorbed on anionic resin of the quaternary ammonium type (Dowex 1X8) 100-200 \"mesh\". The production systems H3 10BO3 were evaluated individually and in cascade process with 10B transfer between both systems. The measurements of B in this study were evaluated by Inductively Coupled Plasma Mass Spectrometry and Thermal Ionization Mass Spectrometry. In the S1 columns system displacement after 243 m (135 DBC) was possible obtain an medium enrichment in the last 20 cm, of 40 % atoms 10B, corresponding to 2830 mg of H310BO3. This mass was transferred to the S2 column system which have introduced in the last 20 cm of the band medium enrichment of 47,8 atom% 10B and this new band chromatography was displaced 21,6 m, thus obtaining the last centimeter band (1-0 cm) from enriched fraction 82 % atoms 10B. The fractionation factor (\'alfa\') and the Height Equivalent of Theoretical Plate (HETP) of stable isotopes of B (10B and 11B) was determined like being 1,0245 and 0,30 cm, respectively

Kommerziell erhältliche Ionenaustauscher basieren häufig auf funktionalisierten Cellulosemembranen, die mit CerIV und Glycidylmethacrylat (GMA) gepfropft und anschließend sulfoniert werden.  Die Untersuchung dieser Polymerisation zeigte, dass während der Pfropfung eine Vernetzung des Polymers über die Epoxidfunktion des Monomers auftritt. Daher konnte keine direkte Analyse des entstandenen Hydrogels durchgeführt werden und es wurde stattdessen Methylmethacrylat (MMA) auf der Oberfläche polymerisiert. Nach Entwicklung eines geeigneten Verfahrens zur Zersetzung der Membranen und Isolierung des Pfropfpolymers konnte dieses mit Gel-Permeations-Chromatographie (GPC) analysiert werden. Zusätzlich wurden Polymerisationen auf nicht-porösem Cellophan durchgeführt und die erhaltenen Proben mittels Rasterkraftmikroskopie (Atomic Force Microscopy, AFM) untersucht.  Die Ergebnisse zeigen, dass das gepfropfte PMMA einen Polymerisationsgrad von 2100 und eine Dichte von 0,45 Ketten pro nm2 auf der Oberfläche hat. Wird die gleiche Anzahl an Polymeren auch für Pfropfung mit PGMA angenommen und mit dem Pfropfgrad verglichen, ergibt sich damit unter Vernachlässigung der Vernetzung ein Polymerisationsgrad von etwa 800. Es konnte gezeigt werden, dass die für die Pfropfung verwendete Emulsion unter anderem aus Tröpfchen besteht, deren Größe mit der der Poren der Membran übereinstimmt. Dennoch treten bei der Polymerisation keine Ausschlusseffekte auf und die Größenverteilung der Emulsionspartikel stellt sich auch nach Filtration zügig wieder ein. Zusätzlich wurde eine Methode der Atom-Transfer radikalischen Polymerisation (ATRP) auf mikroporösen Membranen entwickelt und eingesetzt, um gezielt bestimmte Eigenschaften des Hydrogels zu variieren. Bei Versuchen mit MMA wurde der reversibel deaktivierte Charakter unter den verwendeten Bedingungen untersucht und nachgewiesen.  Die verwendete Methode erlaubt, die Kettenanzahl und –länge separat voneinander einzustellen, sodass der Einfluss dieser Größen auf die Eigenschaften des resultierenden Membranadsorbers gezielt untersucht werden konnte. Es zeigte sich, dass die Dichte der Ketten einen komplexen Einfluss sowohl auf die Permeabilität als auch auf die Bindungskapazität des Ionentauschers hat. Der Einfluss der Kettenlänge ist dagegen weniger subtil und entspricht den Erwartungen.  Aus den gewonnenen Daten wurde ein Modell für die Bindung von Proteinen an der gepfropften Oberfläche des Austauschers entwickelt und daraus die Kettenlänge und –dichte des Hydrogels abgeschätzt und mit alternativen Methoden verglichen.

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