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Behavior of phenols and phenoxyacids on a bisphenol-A imprinted polymer. Application for selective solid-phase extraction from water and urine samples.

Herrero-Hernández E, Carabias-Martínez R, Rodríguez-Gonzalo E - Int J Mol Sci (2011)

Bottom Line: In an aqueous medium, hydrophobic interactions were found to exert a remarkably non-specific contribution to the overall binding process.Several parameters affecting the extraction efficiency of the BPA-MIP were evaluated to achieve the selective preconcentration of phenols and phenoxyacids from aqueous samples.The possibility of using the BPA-MIP as a selective sorbent to preconcentrate these compounds from other samples such as urine and river water was also explored.

View Article: PubMed Central - PubMed

Affiliation: Institute of Natural Resources and Agrobiology (IRNASA-CSIC), 37008 Salamanca, Spain; E-Mail: eliseo.herrero@irnasa.csic.es.

ABSTRACT
A molecularly imprinted polymer (MIP), obtained by precipitation polymerisation with 4-vinylpyridine as the functional monomer, ethylene glycol dimethacrylate as cross-linker, and bisphenol-A (BPA) as template, was prepared. The binding site configuration of the BPA-MIP was examined using Scatchard analysis. Moreover, the behaviour of the BPA-MIP for the extraction of several phenolic compounds (bisphenol-A, bisphenol-F, 4-nitrophenol, 3-methyl-4-nitrophenol) and phenoxyacid herbicides such as 2,4-D, 2,4,5-T and 2,4,5-TP has been studied in organic and aqueous media in the presence of other pesticides in common use. It was possible to carry out the selective preconcentration of the target analytes from the organic medium with recoveries of higher than 70%. In an aqueous medium, hydrophobic interactions were found to exert a remarkably non-specific contribution to the overall binding process. Several parameters affecting the extraction efficiency of the BPA-MIP were evaluated to achieve the selective preconcentration of phenols and phenoxyacids from aqueous samples. The possibility of using the BPA-MIP as a selective sorbent to preconcentrate these compounds from other samples such as urine and river water was also explored.

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Chromatograms obtained for the MISPE extraction of 20 mL urine spiked with 25 μg L−1 of each analyte, without (a) and with (b) the addition of 5% of acetonitrile to the sample. Washing step: 5 mL of dichloromethane. Elution step: 5 mL of acetonitrile:acetic acid (9:1, v/v).
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f6-ijms-12-03322: Chromatograms obtained for the MISPE extraction of 20 mL urine spiked with 25 μg L−1 of each analyte, without (a) and with (b) the addition of 5% of acetonitrile to the sample. Washing step: 5 mL of dichloromethane. Elution step: 5 mL of acetonitrile:acetic acid (9:1, v/v).

Mentions: Urine is representative of highly complex matrices. Figure 6a shows the chromatogram obtained when 20 mL of urine (from healthy volunteers, and previously frozen, thawed and filtered) spiked with all the analytes (phenols, phenoxyacids, DEA, CMPU, Atz, Clt, Cbl and Din) at 25 μg L−1 was passed through the MIP and analyzed following the indicated procedure. Peaks corresponding to BPF, 2,4,5-T, BPA and 2,4,5-TP were detected. Also, a broad band appeared at the beginning of the chromatogram. In order to obtain a cleaner chromatogram, an additional step was included in the MISPE protocol; this involved the addition of 5% (v/v) of acetonitrile to the urine sample before passing it through the MIP. The introduction of this new step in the extraction procedure produced cleaner chromatograms (Figure 6b), and peaks corresponding to BPF, 3Me4NOPL, 2,4,5-T, BPA and 2,4,5-TP were readily identifiable and the recovery values were in the range 54% for 3Me4NOPL and 96% for BPA, with detection limits, for a signal to noise ratio of 3, in the range 5.3 μg L−1 for 3Me4NOPL and 0.9 μg L−1 for BPA and 2,4,5-TP. Thus, the MISPE procedure proved to be simple and effective for the elimination of substances that can interfere in analyte detection or that may damage the chromatographic system. To improve the detection limits in urine samples, the appropriate sample treatment should be optimized.


Behavior of phenols and phenoxyacids on a bisphenol-A imprinted polymer. Application for selective solid-phase extraction from water and urine samples.

Herrero-Hernández E, Carabias-Martínez R, Rodríguez-Gonzalo E - Int J Mol Sci (2011)

Chromatograms obtained for the MISPE extraction of 20 mL urine spiked with 25 μg L−1 of each analyte, without (a) and with (b) the addition of 5% of acetonitrile to the sample. Washing step: 5 mL of dichloromethane. Elution step: 5 mL of acetonitrile:acetic acid (9:1, v/v).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3116193&req=5

f6-ijms-12-03322: Chromatograms obtained for the MISPE extraction of 20 mL urine spiked with 25 μg L−1 of each analyte, without (a) and with (b) the addition of 5% of acetonitrile to the sample. Washing step: 5 mL of dichloromethane. Elution step: 5 mL of acetonitrile:acetic acid (9:1, v/v).
Mentions: Urine is representative of highly complex matrices. Figure 6a shows the chromatogram obtained when 20 mL of urine (from healthy volunteers, and previously frozen, thawed and filtered) spiked with all the analytes (phenols, phenoxyacids, DEA, CMPU, Atz, Clt, Cbl and Din) at 25 μg L−1 was passed through the MIP and analyzed following the indicated procedure. Peaks corresponding to BPF, 2,4,5-T, BPA and 2,4,5-TP were detected. Also, a broad band appeared at the beginning of the chromatogram. In order to obtain a cleaner chromatogram, an additional step was included in the MISPE protocol; this involved the addition of 5% (v/v) of acetonitrile to the urine sample before passing it through the MIP. The introduction of this new step in the extraction procedure produced cleaner chromatograms (Figure 6b), and peaks corresponding to BPF, 3Me4NOPL, 2,4,5-T, BPA and 2,4,5-TP were readily identifiable and the recovery values were in the range 54% for 3Me4NOPL and 96% for BPA, with detection limits, for a signal to noise ratio of 3, in the range 5.3 μg L−1 for 3Me4NOPL and 0.9 μg L−1 for BPA and 2,4,5-TP. Thus, the MISPE procedure proved to be simple and effective for the elimination of substances that can interfere in analyte detection or that may damage the chromatographic system. To improve the detection limits in urine samples, the appropriate sample treatment should be optimized.

Bottom Line: In an aqueous medium, hydrophobic interactions were found to exert a remarkably non-specific contribution to the overall binding process.Several parameters affecting the extraction efficiency of the BPA-MIP were evaluated to achieve the selective preconcentration of phenols and phenoxyacids from aqueous samples.The possibility of using the BPA-MIP as a selective sorbent to preconcentrate these compounds from other samples such as urine and river water was also explored.

View Article: PubMed Central - PubMed

Affiliation: Institute of Natural Resources and Agrobiology (IRNASA-CSIC), 37008 Salamanca, Spain; E-Mail: eliseo.herrero@irnasa.csic.es.

ABSTRACT
A molecularly imprinted polymer (MIP), obtained by precipitation polymerisation with 4-vinylpyridine as the functional monomer, ethylene glycol dimethacrylate as cross-linker, and bisphenol-A (BPA) as template, was prepared. The binding site configuration of the BPA-MIP was examined using Scatchard analysis. Moreover, the behaviour of the BPA-MIP for the extraction of several phenolic compounds (bisphenol-A, bisphenol-F, 4-nitrophenol, 3-methyl-4-nitrophenol) and phenoxyacid herbicides such as 2,4-D, 2,4,5-T and 2,4,5-TP has been studied in organic and aqueous media in the presence of other pesticides in common use. It was possible to carry out the selective preconcentration of the target analytes from the organic medium with recoveries of higher than 70%. In an aqueous medium, hydrophobic interactions were found to exert a remarkably non-specific contribution to the overall binding process. Several parameters affecting the extraction efficiency of the BPA-MIP were evaluated to achieve the selective preconcentration of phenols and phenoxyacids from aqueous samples. The possibility of using the BPA-MIP as a selective sorbent to preconcentrate these compounds from other samples such as urine and river water was also explored.

Show MeSH