Abstract:Styrene is used in a variety of chemical industries. Environmental and occupational exposures to styrene occur predominantly through inhalation. The major metabolite of styrene is present in two enantiomeric forms, chiral R- and S- hydroxy-1-phenyl-acetic acid (R-and S-mandelic acid, MA). Thus, the concentration of MA, particularly of its enantiomers, has been used in urine tests to determine whether workers have been exposed to styrene. This study describes a method of analyzing mandelic acid using molecular … Show more
“…Efforts to employ MIPs in assays have extended well beyond the large volume of literature focused upon MIPSE, most notably CE and CEC, and LC . In contrast to the 1990s and early 2000s, the proportion of studies devoted to, or heavily dependent upon, LC has reduced significantly.…”
SummaryHerein we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004 to 2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004 which were omitted in the first instalment of this series covering the years 1930 to 2003. 1 In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed.2
“…Efforts to employ MIPs in assays have extended well beyond the large volume of literature focused upon MIPSE, most notably CE and CEC, and LC . In contrast to the 1990s and early 2000s, the proportion of studies devoted to, or heavily dependent upon, LC has reduced significantly.…”
SummaryHerein we present a survey of the literature covering the development of molecular imprinting science and technology over the years 2004 to 2011. In total, 3779 references to the original papers, reviews, edited volumes and monographs from this period are included, along with recently identified uncited materials from prior to 2004 which were omitted in the first instalment of this series covering the years 1930 to 2003. 1 In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by sections describing fundamental aspects of molecular imprinting including the development of novel polymer formats. Thereafter, literature describing efforts to apply these polymeric materials to a range of application areas is presented. Current trends and areas of rapid development are discussed.2
“…O frasco foi então selado e colocado em banho ultratermostático (Quimis, modelo Q214D2) a 4ºC adaptado com uma câmara contendo lâmpada UV (365nm/100W). O tempo de polimerização foi de 6 horas [5] . Após a polimerização, o frasco foi retirado do banho e o clorofórmio (sobrenadante) foi retirado com o auxílio de uma pipeta.…”
Section: Síntese Dos Mips E Nipunclassified
“…Apresentam características vantajosas como estabilidade, robustez, seletividade, resistência a altas temperaturas e pressões e inércia química a ácidos, bases e solventes orgânicos [4] . Em função dessas características, e dada sua alta seletividade, esses polímeros têm sido bastante empregados no preparo de amostras atuando como adsorventes em técnicas de separação, tais como, cromatografia líquida de alto desempenho [5] , eletroforese capilar [6] , eletrocromatografia capilar [6] , cromatografia em camada delgada [7] , bem como em extração em fase sólida (SPE) [8] e em microextração em fase sólida [9] , sendo ainda muito empregados nas áreas biológica, farmacológica e alimentícia [10] . O emprego de MIPs como materiais adsorventes na técnica de SPE vem adquirindo destaque, sendo esse o principal campo de aplicação desses materiais, pois oferece alto grau de seletividade quando comparado com outros materiais, como cartuchos de sílica modificada (C18) e resinas de troca iônica e, ao mesmo tempo, por serem mais estáveis que os adsorventes de origem biológica [11,12] .…”
ResumoPolímeros Molecularmente Impressos (MIPs) são polímeros sintéticos que apresentam alta seletividade a uma molécula de interesse. O objetivo deste trabalho foi a síntese e caracterização de MIPs para aplicação na extração em fase sólida (SPE), visando a determinação de fenilalanina. Os MIPs foram sintetizados a partir do MAA, fenilalanina, EGDMA, AIBN, em clorofórmio. Também foi sintetizado o polímero não-impresso (NIP), para controle da seletividade dos MIPs. A dessorção da fenilalanina foi realizada em extrator Soxhlet. Os MIPs e NIP foram caracterizados pelas técnicas de análise: FTIR, UV-Vis, MEV, DSC e TG. O MIP apresentou maior capacidade adsortiva à fenilalanina do que o NIP, com uma taxa média de adsorção de 55% comparada a 11% para o NIP. Por MEV o MIP apresentou superfície mais porosa, importante característica para aplicação em SPE. Os estudos realizados mostraram que o MIP sintetizado apresentou grande potencial para aplicação em técnica de SPE.
Palavras-chave: síntese e caracterização, MIP, fenilalanina, extração em fase sólida.
AbstractMolecularly imprinted polymers (MIPs) are synthetic polymers that have high selectivity to a molecule of interest. The objective of this work was the synthesis and characterization of MIPs for use in solid phase extraction (SPE), in order to determine Phenylalanine. The MIPs were synthesized from the MAA, Phenylalanine, EGDMA AIBN, in chloroform. Non imprinted polymer (NIP) was synthesized to control the selectivity of MIPs. The desorption of Phenylalanine was carried out in Soxhlet extractor. The MIPs and NIP were characterized by the following analytical techniques: FTIR, UV-Vis, SEM, DSC and TG. MIP showed higher adsorption capacity to Phenylalanine than the NIP with an average rate of adsorption of 55% compared to 11% for NIP. SEM MIP showed more porous surface, an important feature for use in SPE. The synthesized MIP in the present study showed great potential for use in SPE technique.
known whether organic matter or inorganic matter first brought chiral sources to our planet. In the field of chiral materials, chirality transfer system between organics and inorganics deserve to be a vitally important area to bring meaningful hints to not only the origins of life but also the development of chiral materials. The concept in this article is a radical synthesis of chiral polymers from achiral monomers employing a chiral inorganic silica as a chiral reaction matrix where chiral information could be transferred from silica to polymers.Chiral polymers have received much attention due to its unique stereochemistry and functionality, and many efforts have been devoted to the extension of their synthetic ways and applications. [12][13][14] One of general ways for the synthesis of chiral polymers involves the polymerization of optically active monomers. [15][16][17][18] However, this is not convenient due to the tedious synthesis of optically active monomers. The asymmetric polymerization, which directly produced chiral polymers starting from prochiral (achiral) monomers, is much more fascinating, and has been widely employed to design a variety of chiral polymers for the last several decades. There are some effective ways to synthesize chiral polymers that began from achiral monomers in conjunction with chiral reagents or catalysts. For instance, helix-sense-selective polymerization can afford chiral polymers with stable helical conformations via polymerization of achiral monomers having a large steric hindrance, in which the direction of the helicity could be entirely controlled by chiral catalysts, [19][20][21] initiators, [22,23] solvents, [24][25][26] and additives. [27][28][29] Besides that, chiral molecular imprinting is the simple technique of creating chiral recognition holes inside polymeric matrixes, which are complementary to the template of chiral molecules. [30][31][32] Other than the use of molecular-level assistances as chiral sources, the utilization of chiral nematic phase as a polymerization solvent is thought to be one of the effective methods to endow the helical organization on the resulting conjugated polymers. [33][34][35] Indeed, the asymmetric synthesis of chiral polymers has been remarkably advanced with the development of chiral reagents or catalysts, which play an essential role in the control of asymmetric configurations or conformations of the resulting polymer chains. However, the chirality of polymer-specific agents or catalysts has been ruled by organic molecular systems. To the best of our knowledge, there are no examples of using inorganic chiral materials as Chiral polymers are often prepared by two ways depending upon chiral monomers, chiral catalysts, and chiral auxiliaries which always come from organics: one is the enantio-selective polymerization of prochiral or racemic monomers or polymerization of optically active monomers; and the other one is the molecular imprinting technique, which creates chiral recognition sites inside a densely cross-linked polymer gel. H...
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