Ion chromatography (IC) as developed by Small et. al. in 1975 has become an efficient and reliable analytical technique for simultaneous analysis of multiple ions in solution. The principle requirement prior to use the IC for an analysis is sample preparation; these include sample decomposition, solvent extraction, and trapping in case the target element is in the gas phase, etc. Solvent extractions for fluoride, chloride, sodium, ammonium, and potassium ions which are soluble in soils are described. Sample decompositions include silicate rocks using hydrofluoric acid for the determination of phosphorus; organic pesticides using lithium fusion technique for the determination of halide and cyanide ions are also described. After these sample preparation techniques, the aqueous solutions obtained were analyzed on the ion chromatograph for the analyses of the anions and cations mentioned above. Recovery and reproducibility of each technique is in general quite good and the comparison between the results obtained from the IC method and other instrumentation are given.

No description available.

The large scale nitric acid oxidation of common sugars into their corresponding aldaric acids is being investigated as an important source of potentially useful components for industrial applications such as polymers. This thesis details the development of an Ion Chromatography (IC) method for the analysis of these oxidation mixtures and related samples from the work-up and purification processes. The method was developed for use with a Dionex ICS2000 IC system equipped with an AS11-HC column and utilising suppressed conductivity detection. IC proved to be a useful, versatile and straightforward method of studying the reactions and their products. The detected ions include but are not restricted to the anionic salt forms of: D-Glucaric acid, Xylaric acid, Mannaric acid, D-gluconic acid and both keto forms of the same, D-xylonic acid, D-mannonic acid, glycolic acid, oxalic acid, tartaric acid and tartronic acid. Nitrate from the nitric acid used in the oxidation is often observed. The results compare favorably to GC-MS and HPLC analysis of similar samples. An overview of the theory and operation of the instrument along with the method development and results from application to the oxidation mixtures and related samples are presented. As part of the investigation into the range of utility of IC for studying these reactions, a study was made of the retention behaviour of a large number of simple and low molecular weight (LMW) carboxylic acids eluted by the ion chromatography system in use. The results of this study are included with an explanation of the major factors affecting anion retention on the column

Accurate quantification of phosphorus (P) fractions in manures and agricultural runoff is vital to understanding P dynamics in the environment. Phytate is an organic form of P, with 6 phosphate groups, which is found in manures, but is difficult to quantify due to its affinity for complex formation with aluminum (Al) and iron (Fe). The objective of the first study was to measure if high concentrations of aluminum (Al) and iron (Fe) hinder accurate quantification of phytate in dairy manure and broiler litter when measured by high performance ion chromatography (HPIC). In this study dairy manure and broiler litter samples were spiked with Al, Fe, and phytate. Samples were alkaline extracted, acidified,cleaned up and filtered, and then phytate was analyzed with HPIC. High concentrations of Fe did not hinder phytate recovery in manure or litter samples. While phytate recovery was close to 100% at typical manure and litter Al concentrations, high concentrations of Al inhibited phytate recovery in litter samples and in some manure samples. Overall, alkaline extraction of dairy manure and broiler litter and analysis with HPIC proved to be a relatively accurate, fast and cheap within normal Al and Fe ranges, compared to the commonly used NMR method. The developed method was then used to measure the concentration of phytate P (Pp) rather than the entire phytate molecule (6 moles Pp per mole phytate) in runoff waters and in an adsorption study. Phytate P has not been previously measured in runoff, due to the low concentrations of Pp found in runoff and the complexity Pp extraction from runoff. Runoff treatments were dairy manure with and without added Pp (DM, DM+Pp), broiler litter with and without added Pp (BL, BL+Pp), and control, with and without two levels of Pp (control, control Pp low, control Pp high). Runoff was collected under simulated rainfall and analyzed for total and dissolved reactive P (DRP). Runoff was also separated into sediment (>0.45"m) and liquid (<0.45"m and lyophilized) fractions for Pp analysis by high performance ion chromatography (HPIC). The new method for Pp analysis recovered 70% of Pp spiked into runoff samples. Phytate P was found only on the sediment fraction of runoff and was not detected in the liquid fraction, even when it was lyophilized and extracted. This agreed with the adsorption study, which showed strong adsorption of Pp. Phytate P loss from control Pp high was significantly greater than Pp loss from control. �When control Pp high was removed from analysis, Pp loss from BL, BL+Pp, DM, and DM+Pp was significantly greater than from control. Phytate P in the manures appeared to behave differently than pure Pp salts, likely to do the formation of protein-phytate and cation-phytate complexes in the manures. Phytate P had no effect on DRP in runoff for any treatment, indicating no significant release of inorganic P through competitive binding. The majority of P lost in runoff was in fractions other than DRP and Pp in the sediment fraction. Efforts to control the erosive loss of soil during rainfall events appear to be the best way to reduce total P loss, irrespective of the presence of Pp. / Master of Science

Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2017-03-17T19:14:35Z No. of bitstreams: 1 Ribeiro, Anézia Lima Chaves [Dissertação, 2011].pdf: 3144917 bytes, checksum: 028a1b168bde80a2bfe9b881b9c28b08 (MD5) / Made available in DSpace on 2017-03-17T19:14:35Z (GMT). No. of bitstreams: 1 Ribeiro, Anézia Lima Chaves [Dissertação, 2011].pdf: 3144917 bytes, checksum: 028a1b168bde80a2bfe9b881b9c28b08 (MD5) / O glifosato é um herbicida organofosforado amplamente utilizado que constitui um poluente potencial do meio ambiente; ácido aminometilfosfônico (AMPA) é o seu principal metabólito. O objetivo deste estudo foi desenvolver um método direto rápido e sensível para a quantificação dos herbicidas, a fim de monitorar seus resíduos na água de diferentes fontes. Além disso, este estudo teve como objetivo elaborar um procedimento para a determinação simultânea de glifosato, AMPA e F-, Cl-, Br-, NO3 -, SO4 2- e PO4 3- na água. Em ambos os casos, foram usados a cromatografia de troca iônica com detecção condutométrica. A determinação de glifosato pode ser realizada em modo isocrático (6,0 mmol L-1 Na2CO3 e 2,0 mmol L-1 NaHCO3), enquanto a separação simultânea de glifosato, AMPA e ânions foi realizada por gradiente com as seguintes fases móveis: A: 15,0 mmol L-1 NaOH + 1,0 mmol L-1 Na2CO3 e B : Na2CO3 - 15,0 mmol L-1. A confirmação de espécies AMPA (m / z = 110) e glifosato (m / z = 168) foi realizada pelo IC-MS. A determinação do isótopo 31P por ICPMS permitiu a determinação indireta destas espécies e um teste de recuperação resultou em cerca de 105%. O método foi validado utilizando matrizes de agua ultrapura, agua superficial, mineral e água subterrânea. Por eluição isocrática, os limites de detecção (LODs) encontrados para o glifosato foram: 10 μgL-1 em água ultrapura , 54 μgL-1 em água subterrânea. Para a determinação simultânea de glifosato e AMPA, os LODs foram: 9,6 μgL-1 , 9,8 μgL-1 (água ultrapura), 9,5 μgL-1 , 60 μgL-1 (água mineral), 12,4 , 29,7 μgL-1 (agua superficial) respectivamente para glifosato e AMPA. A determinação de glifosato por IC/Condutimetria mostrou-se adequada à aplicação em águas naturais, alcançando valores de LD muito abaixo dos permitidos pela legislação vigente (500 μgL-1; Portaria MS 518 de 25/03/2004 e Resolução CONAMA 396 de 03/04/2008) e, também outros órgão internacionais como EPA, sem necessidade de preparação prévia da amostra como extração, pré-concentração e derivatização / Glyphosate is a widely used organophosphorated herbicide, which constitutes a potential pollutant of the environment; aminomethylphosphonic acid (AMPA) is its main metabolite. The purpose of this study was to develop a direct, rapid and sensitive method for quantification of the herbicide in order to monitor its residues in water from different sources. Furthermore, this study aimed to draw up a procedure for the simultaneous determination of glyphosate, AMPA and F-, Cl-, Br-, NO3 -, SO4 2- and PO4 3- in water. In both cases, ion-exchange chromatography with conductimetric detection were used. The determination of glyphosate could be performed in isocratic mode (6.0 mmol L-1 Na2CO3 and 2.0 mmol L-1 NaHCO3), while the simultaneous separation of glyphosate, AMPA and anions was performed by gradient elution with the following mobile phases: A - 15.0 mmol L-1 NaOH + 1.0 mmol L-1 Na2CO3 and B - 15.0 mmol L-1 Na2CO3. Confirmation of species AMPA (m/z = 110) and glyphosate (m/z = 168) were carried out by IC-MS. The determination of the isotope 31P by ICPMS allowed the indirect determination of these species and a recovery test resulted in about 105%. The method was validated using ultrapure, river, mineral and groundwater. With isocratic elution, limits of detection (LODs) of 10 μg L-1 in ultrapure water and 54 μg L-1 in groundwater were found for glyphosate. For the simultaneous determination of glyphosate and AMPA, LODs were, respectively, 9.6 μg L-1, 9.8 μg L-1 (ultrapure water), 9.5 μg L-1, 60 μg L-1 (mineral water), 12.4 μg L-1, 29.7 μg L-1 (river water). The determination of glyphosate IC / Conductimetry proved to be suitable for application in natural waters, reaching LD values far below those allowed by legislation (500 μg L-1), MS portaria 518 of 25/03/2004 and CONAMA Resolution 396 of 03 / 04/2008), and also other international bodies such as EPA, without previous sample preparation and extraction, pre-concentration and derivatization

Successful implementation of dietary P management strategies demand improved understanding of P digestion dynamics in ruminants and this is not possible without a reliable and accurate phytate (Pp) quantification method. The objective of the first study was to develop a robust, accurate, and sensitive method to extract and quantify phytate in feeds, ruminant digesta and feces. Clean-up procedures were developed for acid and alkaline extracts of feed, ruminant digesta and feces and clarified extracts were analyzed for Pp using high performance ion chromatography (HPIC). The quantified Pp in acid and alkaline extracts was comparable for feed but alkaline extraction yielded greater estimates of Pp content for digesta and feces than did acid extraction. Extract clean-up procedures successfully removed sample matrix interferences making alkaline extraction compatible with HPIC. The developed method was applied to investigate the disappearance of Pp from the large intestine of dairy heifers. Eight ruminally- and ileally-cannulated crossbred dairy heifers were used and each heifer was infused ileally with 0, 5, 15, or 25 g/d Pp and total fecal collection was conducted. On average 15% of total Pp entering the large intestine was degraded but the amount of infused Pp did not influence the degradability of Pp. Net absorption of P from the large intestine was observed. A feeding trial was conducted to investigate the effect of dietary Pp supply on ruminal and post-ruminal Pp digestion. Six ruminally-and ileally-cannulated crossbred lactating cows were used and dietary treatments were low (0.10% Pp), medium (0.18% Pp), and high (0.29% Pp) Pp, and a high inorganic P (Pi; 0.11% Pp; same total P content as high Pp). Ruminal Pp digestibility increased linearly with dietary Pp. As in the infusion study, net disappearance of Pp from the large intestine was only 16% of total Pp entering the large intestine and not influenced by dietary Pp. Fecal P excretion increased linearly with increasing dietary Pp but was not affected by form of dietary P. In lactating cows Pp digestibility was not affected by dietary Pp and fecal P excretion was regulated by total dietary P rather than by form of dietary P. / Ph. D.

Gradient surfaces exhibit a variation in functionality along the length of the surface. One method for preparing gradients is controlled-rate infusion (CRI). In Part 1 of this work, CRI was used to prepare gradients for the purpose of separating transition and heavy metals. Initial work on this project was focused on controlling the retention of the metal ions by varying the number of amine groups, aminoalkoxysilane concentration, and the infusion time. The retention factors of four metal ions varied predictably with increasing number of amine groups, increasing aminoalkoxysilane concentration, and increasing infusion time, producing small but useful changes in the retention factors. The continuation of this project involved the preparation of two-dimensional multi-component gradients on TLC plates, which were used to separate six transition and heavy metals. The retention, and thus the separation, was affected by the presence or absence of a gradient and the direction of the gradient. Part 2 of this work focused on understanding the factors that motivated instructors in the early and late stages in the process of change. Instructors who attended the POGIL-PCL (Process-Oriented Guided Inquiry Learning in the Physical Chemistry Laboratory) workshops were asked to complete online surveys. The goals of the first survey were to understand the factors that initially interested instructors in POGIL-PCL, to determine if instructors enter the implementation stage, and to understand the factors that affect how instructors implement POGIL-PCL. Later surveys were designed to explore the development of the POGIL-PCL network and assess whether implementation is sustained over time.

[pt] A administração de antimoniais no tratamento da leishmaniose é uma rara oportunidade para estudar o metabolismo de antimônio e das suas espécies químicas. Tais estudos são de grande relevância, uma vez que não se tem conhecimento sobre os metabólitos formados no corpo humano e da sua possível importância na erradicação dos parasitas causadoras da doença, assim como sobre os mecanismos de eliminação deste elemento tóxico. Ao contrário do arsênio, existem poucas metodologias reportadas para a análise de especiação de antimônio em amostras clínicas. O presente trabalho é uma continuação de pesquisas realizadas e publicadas anteriormente, nas quais a técnica de espectrometria de massas (ICPMS) acoplada à cromatografia iônica de alta eficiência IC-(HPLC) foi utilizada para separação e quantificação, em linha, de antimoniato de N-metil glucamina, Sb(V) e Sb(III) em amostras de plasma e urina. Assim, serão apresentados resultados recentes obtidos com o emprego de uma coluna com melhor resolução (Metrosep - A Supp5; 250 mm x 4,0 mm; Metrohm, Suíça) na separação de trimetil antimônio (TMSb), Sb(V) e Sb(III). Testes de otimização mostraram que uma solução de EDTA (0,006 mol L-1, pH 4,7) é adequada como fase móvel para a separação das três espécies. Os tempos de retenção para TMSb, Sb(V) e Sb(III) foram de 44,2 s, 150,6 s e 548,4 s, respectivamente, permitindo uma perfeita e repetitiva (DPR <3 por cento) separação dessas espécies. Repetitividades melhores que 4 por cento foram também obtidas na quantificação das áreas dos três picos cromatográficos correspondentes. Curvas analíticas, construídas a partir de soluções padrão das espécies em solução aquosa e em amostras de urina fortificadas, apresentaram ótima linearidade com coeficientes de correlação maiores que 0,999. Para volumes de amostra de 100 uL, injetados na coluna e utilizando-se o espectrômetro ELAN 5000 (PE-Sciex, EUA) como detector multielementar, em combinação com o nebulizador concêntrico tipo Meinhard e uma câmara ciclônica, limites absolutos de quantificação de 0,02 ng de antimônio foram obtidas para as três espécies estudadas. Testes de estabilidade mostraram que Sb(V) sofre alterações químicas já em intervalos de tempo relativamente curtos (maiores que 8h em água, e que 4h em urina fortificada) enquanto que TMSb e Sb(III) evidenciaram estabilidades consideravelmente maiores em ambos os meios. / [en] Clinical applications of antimonials in the treatment of leishmaniasis are a unique opportunity to study the metabolism of antimony and its species in the human body. As little is known about antimony metabolism, studies are required to improve the knowledge about the excretion mechanism of this toxic element; in particular, those which deal with antimony metabolites and the action of antimonials for the eradication of leishmaniasis causing parasites. In contrast with its chemical analogue arsenic, only a few methods concerning antimony speciation in clinical samples have been described in the literature. The aim of the present work was to improve a method previously developed to separate and quantify N-methyl meglumine antimoniate, Sb(V) and Sb(III) in blood plasma and urine samples by using anion exchange high performance liquid chromatography (IC-HPLC) coupled with inductively-coupled plasma mass spectrometry (ICPMS). Results on the application of an ion chromatography column (Metrosep - A Supp5; 250 mm x 4.0 mm; Metrohm, Swiss) with better resolution for the separation of TMSb, Sb(V) and Sb(III) are presented. The optimum conditions for the separation of the three species were established with 0.006 mol L-1 EDTA at pH 4.7 as the mobile phase. The retention times for TMSb, Sb(V) and Sb(III) were 44,2 s, 151,6 s and 548,4 s, respectively. A robust linear relationship between concentration and peak area was obtained for the three species, both, in aqueous standard solutions and spiked urine samples, with an associated correlation factor higher than 0,999. Relative standard deviations below 4 percent have been obtained in the peak area quantification mode. When using the ELAN 5000 (PerkinElmer-Sciex, EUA) equipped with a concentric Meinhard nebulizer in combination with a cyclonic spray chamber as detector, and employing a 100-uL injection loop in the HPLC system, typical absolute limits of quantification were 0.02 ng of Sb for each of the three antimony species studied. Stability tests showed that Sb(V) suffers chemical alterations within a short time period (>8h in aqueous solutions and >4h in spiked urine), whereas TMSb and Sb(III) presented better stability conditions in both solutions.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A quantidade de resíduos gerados tem crescido rapidamente, sendo maior que a taxa de crescimento populacional, indicando um aumento na geração per capita. Este fato torna preocupante a maneira como é realizada a disposição final de resíduos e o impacto ambiental gerado com isso. Dentre os impactos está a produção de chorume, um poluente de elevada carga orgânica com altas concentrações de amônio e forte coloração, produzido pela decomposição química e microbiológica dos resíduos sólidos depositados em um aterro. Em locais de destino como aterros sanitários, este chorume é drenado para tratamento a fim de não impactar o local onde foi implantado o aterro. Porém, no Brasil, em grande parte dos casos, este tratamento não acontece, deixando o ambiente mais suscetível à contaminação. Este trabalho teve como finalidade determinar a quantidade de amônio presente em amostras de chorume do aterro de Gramacho no Rio de Janeiro, utilizando a cromatografia de íons para a sua quantificação, além de estudar a remoção de amônio por processos de adsorção em materiais como argilominerais. As amostras de chorume in natura apresentaram valores de pH em torno de 8,0 e concentrações de amônio entre 1665,0 e 2788,8 mg.L-1. Nas amostras analisadas após a destilação do chorume foram encontrados valores de pH entre 8,6 e 9,7 e concentrações de amônio de até 6362,3 mg.L-1, verificando que a maior concentração deste íon é arrastada nos primeiros 50 mL da destilação. Os testes de adsorção obtiveram um potencial de remoção de até 47 % do total de amônio. A metodologia aplicada se mostrou eficiente para determinação de amônio, uma vez que o tratamento prévio minimiza a ação de interferentes. Os baixos valores de remoção de amônio reforçam a necessidade de maior aprofundamento deste estudo, o que seria uma alternativa interessante para minimizar a ação deste poluente no meio ambiente / The amount of waste generated has grown rapidly, being larger than the population growth rate, indicating an increase in per capita generation becoming worrisome, as the final disposal of waste is performed and environmental impact. Among the impacts, is the production of leachate, a high organic pollutant with high concentrations of ammonium and strong staining, produced by chemical and microbiological decomposition of solid waste deposited in a landfill. In destinations such as landfills, the leachate is drained to the treatment to minimize the impact at the local landfill where it was deployed. However, in Brazil, in most cases, this treatment does not happen, leaving the environment more susceptible to contamination. This study aimed to determine the amount of ammonium present in samples of leachate from Gramacho landfill in Rio de Janeiro, using ion chromatography for its quantification, and perform a preliminary study of ammonium removal by adsorption processes in materials as clay minerals. The samples of fresh leachate had pH values around 8.0 and ammonium concentrations between 1665.0 and 2788.8 mg.L-1. In samples analyzed after the leachate distillation were found pH between 8.6 and 9.7 and ammonium concentrations of up to 6362.3 mg.L-1, noting that the largest concentration of this ion is drawn in the first 50 mL of distillation. The adsorption tests had a potential to remove up to 47 % of total ammonia. The methodology is efficient for determination of ammonium, since the pretreatment minimizes the action of interfering components. The low levels of ammonium removal reinforce the need for more study, which would be an interesting alternative to minimize the action of this pollutant in the environment

Resorcinarenes can be functionalized at their upper and lower rims. In this work, the upper rim of a resorcinarene was functionalized with glutamic acids and the lower rim was functionalized with either methyl or undecyl alkyl groups. The cavitands were characterized by nuclear magnetic resonance (NMR), mass spectrometry (MS), UV-vis spectroscopy, dynamic light scattering (DLS) and electron microscopy. The binding of resorcinarene with amine guests was studied in DMSO by UV-vis titration. The obtained binding constants (K values) were in the range of 12,000-136000 M-1. The resorcinarenes were shown to form aggregates in a variety of solvents. The aggregates were spherical as confirmed by DLS, SEM and TEM experiments. Dynamic light scattering (DLS) experiments revealed the size of the aggregates could be controlled by cavitand concentration, pH, and temperature. The resorcinarene with undecyl alkyl group were adsorbed onto 55% cross-linked styrene-divinylbenzene resin to prepare a new stationary phases for ion chromatography (IC) columns. The new column packing material was applied in determination of uremic toxins and water contaminants. The new IC column afforded separation of the five uremic toxins : guanidinoacetic acid, guanidine, methylguanidine, creatinine, and guanidinobenzoic acid in 30 minutes. Detection and quantification of uremic toxins helps diagnose kidney problems and start patient care. Gradient elutions at ambient temperature with methanesulfonic acid (MSA) as eluent resulted in detection levels in water from 10 to 47 ppb and in synthetic urine from 28 to 180 ppb. Trace levels of creatinine (1 ppt) were detected in the urine of a healthy individual using the columns. The new IC stationary phase separated cationic pharmaceuticals including a group of guanidine compounds in surface water. Detection limits in the range of 5 - 32 µg L-1 were achieved using integrated pulsed amperometric detection (IPAD) for guanidine (G), methylguanidine (MG), 1,1-dimethylbiguanidine (DMG), agmatine (AGM), guanidinobenzoic acid (GBA) and cimetidine (CIM). Suppressed conductivity (CD) and UV-vis detection resulted in limits of detection similar to IPAD, in the range of 1.7 - 66 µg L-1, but were not able to detect all of the analytes. Three water sources, river, lake, and marsh, were analyzed and despite matrix effects, sensitivity for guanidine compounds was in the 100 µg L-1 range and apparent recoveries were 80-96 %. The peak area precision was 0.01 - 2.89% for IPAD, CD and UV-vis detection.