Capillary Columns
Mostrando 1-12 de 30 artigos, teses e dissertações.
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1. Synthesis of Hybrid Monolithic Columns Using a Click Chemistry Reaction for Application in Capillary Liquid Chromatography
Hybrid monolithic columns present characteristics of both silica and organic monoliths, such as good mechanical properties, wide pH tolerance, high permeability and stability and little swelling or shrinkage. A common way to prepare this type of material is by using alkoxysilanes and organic monomers via the sol-gel process and click chemistry reactions. In
J. Braz. Chem. Soc.. Publicado em: 24/10/2019
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2. CONSTRUÇÃO DE UM DISPOSITIVO DE PRESSURIZAÇÃO A VÁCUO PARA A PREPARAÇÃO DE FASES ESTACIONÁRIAS MONOLÍTICAS VIA PROCESSO SOL-GEL
The filling of capillaries via the sol-gel process is growing. Therefore, this technical note focuses on disseminating knowledge acquired in the Group of Analytical Chemistry and Chemometrics over seven years working with monolithic stationary phase preparation in fused silica capillaries. We believe that the detailed information presented in this technical
Quím. Nova. Publicado em: 2015-01
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3. Physical and electrophoretic characterization of octadecyl methacrylate-based monolithic columns for use in capillary electrochromatography
Colunas de alta eficiência cromatográfica de origem monolítica orgânica foram obtidas para uso em eletrocromatografia capilar (CEC) utilizando uma mistura de monômeros (concentrações constantes) com diferentes proporções de solventes porogênicos (1,4- butanodiol com álcool isoamílico, álcool amílico ou cicloexanol, na presença ou ausência de
J. Braz. Chem. Soc.. Publicado em: 2013-03
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4. A Boophilus microplus vitellin-degrading cysteine endopeptidase
Here we describe the purification and characterization of a vitellin (VT) degrading cysteine endopeptidase (VTDCE) from eggs of the hard tick Boophilus microplus. A homogeneous enzyme preparation was obtained by chromatographic fractionation on ion-exchange and gel filtration columns and an autolysis step. This step consisted of incubation of a semipurified
Publicado em: 2011
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5. Avaliação dos processos de pré-tratamento da superfície da sílica fundida no preparo de colunas capilares inertes para cromatografia gasosa / Evaluation of the processes of pretreatment on the fused-silica surface for preparation of inert capillary columns for gas chromatography
The control of the inner surface in open tubular capillary columns has fundamental importance to reach a high performance in gas chromatography analysis. It was very studied during 1970´s and 1980´s, but has not interested the researches along last years, not excluding also, the possibility of commercial secrets regarding column preparation. The activity o
Publicado em: 2009
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6. Cromatografia gasosa bidimensional abrangente (GC × GC)
This paper presents the fundamental principles, instrumentation and selected applications of comprehensive two-dimensional gas chromatography (GC × GC). In this technique, introduced in 1991, two capillary columns are coupled and proper modulating interfaces continuously collect the eluate from the first column, transferring it to the second column. The res
Química Nova. Publicado em: 2009
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7. Desenvolvimento de instrumentação dedicada a cromatografia líquida capilar (cLC) / Development of dedicated instrumentation to capillary liquid chromatography (cLC)
Since the chromatography was introduced by Tswett, in the beginning of the 20th century, the technique has suffered a constant progress. However, the miniaturization of liquid chromatography, instead of its promising start, it is still too slow and this technique has not reached a wide divulgation so far. It is important to mention that the number of groups
Publicado em: 2008
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8. Cromatografia líquida multidimensional e espectrometria de massas em tandem para análise direta de fármacos em fluidos biológicos: da escala convencional à miniaturizada / Multidimensional liquid chromatography and tandem mass spectrometry for the direct analysis of grugs in biofluids: from the conventional to the miniaturized scale
Analysis of drugs and other related molecules in biofluids is essential in the pharmaceutical field. Nowadays, the development of innovative solutions in analytical chemistry has been pushed by the needs for speed and more complex analysis. Lately, multidimensional liquid chromatography using column switching for direct injection of biofluids has gained atte
Publicado em: 2007
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9. Microextraction techniques applied to the stereoselective analysis of ibuprofen, hydroxychloroquine and their metabolites in human urine. / Técnicas de microextração aplicadas à análise estereosseletiva do ibuprofeno, da hidroxicloroquina e de seus metabólitos em urina
The stereoselective analysis has been standing out in several areas, and it is mainly present in the pharmaceutical industry, since many drugs are marketed as racemic mixtures. The stereoselective analysis employing high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) is very useful for the determination of enantiomers at very low
Publicado em: 2007
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10. Fases estacionárias monolíticas para separações cromatográficas
Monolithic stationary phases represent a new generation of chromatographic separation media. These phases consist of a continuous separation bed prepared by in situ polymerization or consolidation inside the column tubing. In recent years, their simple preparation procedure, unique properties and excellent performance have attracted quite remarkable attentio
Química Nova. Publicado em: 2006-04
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11. Isolamento, identificação, síntese e avaliação de campo do feromônio sexual do minador-dos-citros, Phyllocnistis citrella Stainton, 1856 (Lepidoptera: Gracillariidae) / Isolation, identification, synthesis and field evaluation of the sex pheromone from the citrus leafminer, Phyllocnistis citrella Stainton, 1856 (Lepidoptera: Gracillariidae)
The objectives of this work were to isolate, identify, and synthesize the sex pheromone of Phyllocnistis citrella Stainton, 1856 (Lepidoptera: Gracillariidae), as well as to evaluate its efficiency in field conditions, to rationalize the control of this pest within a Citrus Integrated Pest Management scope. The research was developed at the Insect of Biology
Publicado em: 2006
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12. Análise de fármacos em material biológico: acoplamento microextração em fase sólida "no tubo" e cromatografia líquida de alta eficiência
A new solid phase microextraction (SPME) system, known as in-tube SPME, was recently developed using an open tubular fused-silica capilary column, instead of an SPME fiber, as the SPME device. On-line in-tube SPME is usually used in combination with high performance liquid chromatography. Drugs in biological samples are directly extracted and concentrated in
Química Nova. Publicado em: 2005-10