Different formats of imprinted polymers for determining organotin compounds in environmental samples
Departamento de Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Avenida Complutense S/N, 28040 Madrid, Spain.Journal of Environmental Management (Impact Factor: 2.72). 11/2008; 90 Suppl 1:S69-76. DOI: 10.1016/j.jenvman.2008.07.020
Organotin compounds and their degradation products enter the environment mainly as a result of their use as biocides and antifouling paints. Analysis of these compounds in environmental samples has to be very sensitive and selective so that their concentrations corresponding to the low environmental target values can also be detected. Generally, analysis of a complex matrix leads to high interferences during the different process steps; clean-up procedures are recommended to overcome this problem. For the past many years, solid phase extraction by employing imprinted materials has been extensively used for many organic substances that are used for pre-concentration and clean-up purposes with excellent results. Here, we present three different imprinted polymers prepared via bulk, precipitation, and emulsion polymerization methods that use similar compositions. The synthesized polymer particles were characterized morphologically by employing scanning electron microscopy and Brunauer-Emmett-Teller analysis. Binding properties were calculated using the Langmuir-Freundlich isotherm. Depending on the properties of the materials, different analytical applications for complex matrices are proposed. These applications are mainly used on tributyltin and its degradation products for environmental analysis.
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- "The binding isotherms were calculated using Langmuir and Freundlich equations . The experimental procedure is the same as the described in the previous subparagraph. "
ABSTRACT: A new polymeric material (Patent: P201400535) highly specific for mercury is presented. Its great capability to pre-concentrate and selectively elute inorganic mercury and methylmercury are the main figures of merit. The polymer can be reused several times. To our knowledge, this is the only polymer proposed in the literature for direct inorganic mercury and methylmercury speciation without need of chromatography or quantification by difference. The polymer formation is based on the reaction of a vinyl derivative of 8-hydroxiquinoline as monomer, and 2-(Methacryloylamino) ethyl 2-Methyl Acrylate (NOBE) as co-monomer. Random radical polymerization by the precipitation method was carried out using Azobisisobutyronitrile (AIBN) as initiator. The polymer was characterized by SEM and FTIR. Adsorption binding isotherms were evaluated using Langmuir and Freundlich models, showing high adsorption capacity for both inorganic and organic mercury species. The polymer was employed to sequentially determine inorganic mercury and methylmercury, using a solid phase extraction (SPE) scheme. Cross reactivity of several ions, as well as matrix effects from a high saline matrix like seawater was irrelevant as the retained fractions mostly eluted during the washing step. The procedure was first validated by analyzing a certified reference material (BCR 464) and finally applied to commercial fish samples. The speciation proposed procedure is cheap, fast, and easy to use and minimizes reagents waste.
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ABSTRACT: We have prepared core-shell magnetic molecularly imprinted polymer nanoparticles for recognition and extraction of tributyl tin (TBT). The use of particles strongly improves the imprinting effect and leads to fast adsorption kinetics and high adsorption capacities. The functional monomer acrylamide was grafted to the surface of Fe3O4 nanospheres in two steps, and MIP layers were then formed on the surface by creating a MIP layer on the surface consisting of poly(ethyleneglycol dimethacrylate) with a TBT template. The particles were characterized in terms of morphological, magnetic, adsorption, and recognition properties. We then have developed a method for the extraction of TBT from spiked mussel (Mytilidae), and its determination by liquid chromatography-tandem mass spectrometry. The method has a limit of detection of 1.0 ng g−1 (n = 5) of TBT, with a linear response between 5.0 and 1,000 ng g−1. The proposed method was successfully applied to the determination of trace TBT in marine food samples with recoveries in the range of 78.3–95.6 %. Figure The preparation procedures of core-shell magnetic molecularly imprinted polymer nanoparticles for recognition and extraction of tributyl tin (TBT) in seafood
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ABSTRACT: In the present work the efficiency of molecularly imprinted polymers (MIP) in analytical chemistry, especially for sample pretreatment and for trace element speciation, is discussed. Selectivity of MIP allows reduction of the analysis time and sample handling. Several bulk polymers following covalent and non-covalent strategies by using organotin compounds (OTC) as template molecules have been synthesized. The non-covalent polymer is an excellent approach to be used in solid phase extraction (MISPE) for sea waterorganotin compounds screening. High pre-concentration factors and quantitative recoveries were achieved. Both covalent and non-covalent polymers appeared as a very useful tool for matrix interference removal in complex environmental matrices such as oyster and mussel tissues and sediments. A combination of fast OTC extraction by using a focused ultrasonic probe and MISPE provides a good alternative for OTC determination. Finally, the use of the molecular imprinting technology has been employed to prepare a specific affinity chromatographic stationary phase (ACSP) for OTC speciation by LC-ICP-MS. Detection limits were similar to those obtained with other commercial and not specific stationary phases. These first findings can contribute in the future to propose new LC procedures based on the use of MIPs as an alternative to GC for OTC determination.
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