Elenco delle proposte selezionate per il bando 2009 all'indirizzo: http://azioni-integrate.miur.it/2009/selezionate.html Il progetto è biennale. Di seguito la sintesi in inglese del progetto. One of the most important issue in the analysis of real samples (e.g. environmental waters, sediments, biofluids and foodstuffs) is the enrichment and clean-up of complex samples prior to detection. The analyte is often present in low concentration in a complex mixture of similar compounds and therefore needs to be isolated to be detected by standard analytical techniques. In recent years, solid-phase microextraction (SPME) has emerged as a successful methodology for this purpose. Compared with the conventional extraction techniques, SPME is simple, sensitive, time-efficient, solvent-free, and compatible with analytical separation systems such as gas chromatography, high-performance liquid chromatography and capillary electrophoresis. SPME is based on the partitioning of analytes between the sample and the coating of SPME fibers, so the characteristics of coating are a crucial aspect. Different materials have been developed with the aim to prepare tailor-made compound-specific sorbents thus increasing selectivity and efficiency of sample pretreatment. Molecularly imprinted polymers (MIPs) revealed to be a suitable solution because of high selectivity, chemical stability, and easy preparation characteristics; highly selective MIPs towards a large number of analytes of different (environmental, pharmaceutical, etc.) interest have in fact been prepared. This technique requires the polymerization of functional monomers in the presence of the target analyte that acts as a molecular template. After polymerization, removal of the template leaves behind binding sites in the polymer that are complementary in shape and size to the analyte. Thus, a molecular memory is introduced into the polymer, which is now able to rebind the analyte with a very high selectivity. The fact that MIPs can in principle be prepared against any target molecule and can be used in harsh working conditions, make them extremely attractive as class- or compound-specific sorbents. Other than chemical polymerization, also electrochemical (stoichiometric) polymerization has been applied to MIP synthesis since long time with advantages in term of an easy and rapid deposition of uniform layers with good adherence to a substrate and an easy control of the film thickness by varying the amount of circulated charge. The present project aims to the development of a new class of MIPs to be used as SPME fiber coatings for the analysis of contaminants in environmental and food samples. For the first time, electrosynthesis is proposed as a viable way to directly interface MIP to SPME conducting fiber. Although electrosynthesized polymers have already been used as sorbents in SPME, no example of such prepared MIPs has been reported before. The proposed approach aims to combine MIP selectivity with advantages deriving from electropolymerization. The work will consist of three main steps. Firstly, MIPs based on polypyrrole and/or polyo-phenilenediamine, already used in MIP electrosynthesis, will be prepared against possible target molecules such as pesticides (triazines) and antibiotics (fluoroquinolones). A preliminary check of imprinting will be performed by using electrochemical, spectroscopic and/or piezoelectric techniques. Also imprinted monolithic fibers will be prepared by chemical polymerization for comparative purposes. The second step will consist in the polymer electrosynthesis using a proper electrochemical cell design that could be suitable for subsequent SPME applications (i.e. film deposition on a conducting wire – platinum, gold, glassy carbon... – will be explored). The last step will be MIP application in SPME of analytes from simulated and real samples.
Sviluppo di polimeri a stampo molecolare elettrosintetizzati per applicazioni analitiche in SPME (microestrazione in fase solida)- Azione Integrate Italia-Spagna 2009 (MIUR-Ministerio de Ciencia y Innovación)
MALITESTA, Cosimino;
2009-01-01
Abstract
Elenco delle proposte selezionate per il bando 2009 all'indirizzo: http://azioni-integrate.miur.it/2009/selezionate.html Il progetto è biennale. Di seguito la sintesi in inglese del progetto. One of the most important issue in the analysis of real samples (e.g. environmental waters, sediments, biofluids and foodstuffs) is the enrichment and clean-up of complex samples prior to detection. The analyte is often present in low concentration in a complex mixture of similar compounds and therefore needs to be isolated to be detected by standard analytical techniques. In recent years, solid-phase microextraction (SPME) has emerged as a successful methodology for this purpose. Compared with the conventional extraction techniques, SPME is simple, sensitive, time-efficient, solvent-free, and compatible with analytical separation systems such as gas chromatography, high-performance liquid chromatography and capillary electrophoresis. SPME is based on the partitioning of analytes between the sample and the coating of SPME fibers, so the characteristics of coating are a crucial aspect. Different materials have been developed with the aim to prepare tailor-made compound-specific sorbents thus increasing selectivity and efficiency of sample pretreatment. Molecularly imprinted polymers (MIPs) revealed to be a suitable solution because of high selectivity, chemical stability, and easy preparation characteristics; highly selective MIPs towards a large number of analytes of different (environmental, pharmaceutical, etc.) interest have in fact been prepared. This technique requires the polymerization of functional monomers in the presence of the target analyte that acts as a molecular template. After polymerization, removal of the template leaves behind binding sites in the polymer that are complementary in shape and size to the analyte. Thus, a molecular memory is introduced into the polymer, which is now able to rebind the analyte with a very high selectivity. The fact that MIPs can in principle be prepared against any target molecule and can be used in harsh working conditions, make them extremely attractive as class- or compound-specific sorbents. Other than chemical polymerization, also electrochemical (stoichiometric) polymerization has been applied to MIP synthesis since long time with advantages in term of an easy and rapid deposition of uniform layers with good adherence to a substrate and an easy control of the film thickness by varying the amount of circulated charge. The present project aims to the development of a new class of MIPs to be used as SPME fiber coatings for the analysis of contaminants in environmental and food samples. For the first time, electrosynthesis is proposed as a viable way to directly interface MIP to SPME conducting fiber. Although electrosynthesized polymers have already been used as sorbents in SPME, no example of such prepared MIPs has been reported before. The proposed approach aims to combine MIP selectivity with advantages deriving from electropolymerization. The work will consist of three main steps. Firstly, MIPs based on polypyrrole and/or polyo-phenilenediamine, already used in MIP electrosynthesis, will be prepared against possible target molecules such as pesticides (triazines) and antibiotics (fluoroquinolones). A preliminary check of imprinting will be performed by using electrochemical, spectroscopic and/or piezoelectric techniques. Also imprinted monolithic fibers will be prepared by chemical polymerization for comparative purposes. The second step will consist in the polymer electrosynthesis using a proper electrochemical cell design that could be suitable for subsequent SPME applications (i.e. film deposition on a conducting wire – platinum, gold, glassy carbon... – will be explored). The last step will be MIP application in SPME of analytes from simulated and real samples.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
