Oxidized multi-walled carbon nanotubes for the dispersive solid-phase extraction of quinolone antibiotics from water samples using capillary electrophoresis and large volume sample stacking with polarity switching

Herrera‐Herrera, Antonio V.; Ravelo‐Pérez, Lidia M.; Hernández-Borges, Javier; Afonso, Marı́a M.; Palenzuela, J. Antonio; Rodríguez‐Delgado, Miguel Ángel

doi:10.1016/j.chroma.2011.06.031

Cited by 108 publications

(49 citation statements)

References 73 publications

(51 reference statements)

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“…dSPE has been mainly used for clean-up purposes by adding a suitable sorbent to the organic matrix solution containing the analytes and potential interferences, removing the last of them, rather than for the performance of the extraction. Even so, some works have shown the use of the dSPE mode with good results using different types of sorbents [20][21][22] and, as far as we know, very few [23][24][25][26][27] have used multi-walled carbon nanotubes (MWCNTs) for dSPE. Two of these works have been developed by our group.…”

Section: Introductionmentioning

confidence: 98%

Pesticide residue analysis in cereal-based baby foods using multi-walled carbon nanotubes dispersive solid-phase extraction

et al. 2012

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In the present study, a new analytical method has been developed for the simultaneous quantification of 15 organophosphorus pesticides, including some of their metabolites, (disulfoton-sulfoxide, ethoprophos, cadusafos, dimethoate, terbufos, disulfoton, chlorpyrifos-methyl, malaoxon, fenitrothion, pirimiphos-methyl, malathion, chlorpyrifos, terbufos-sulfone, disulfoton-sulfone and fensulfothion) in three different types of commercial cereal-based baby foods. Dispersive solid-phase extraction (dSPE) with multi-walled carbon nanotubes (MWCNTs) was used together with gas chromatography with nitrogen phosphorus detection. Most favorable conditions involved a previous ultrasound-assisted extraction of the sample with acetonitrile containing formic acid. After evaporation of the extract and redissolution in water, a dSPE procedure was carried out with MWCNTs. The whole method was validated in terms of repeatability, linearity, precision and accuracy and matrix effect was also evaluated. Absolute recoveries were in the range 64-105 % with relative standard deviation values below 7.6 %. Limits of quantification achieved ranged from 0.31 to 5.50 μg/kg, which were lower than the European Union maximum residue limits for pesticide residues in cereal-based baby foods.

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Section: Introductionmentioning

confidence: 98%

Pesticide residue analysis in cereal-based baby foods using multi-walled carbon nanotubes dispersive solid-phase extraction

et al. 2012

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“…Generally, instrumental methods including liquid chromatography [2][3][4], mass spectrometry [5][6][7], and capillary electrophoresis [8][9][10][11] are accurate and sensitive but at the same time they are time consuming, solvent intensive, costly, and greatly rely on laboratory facilities as well as experimental skills. Therefore, these techniques are more suitable for confirmatory analysis than fast screening of a large number of food samples for FQs in field.…”

Section: Introductionmentioning

confidence: 99%

Improved fluoroquinolone detection in ELISA through engineering of a broad-specific single-chain variable fragment binding simultaneously to 20 fluoroquinolones

Wen¹,

Nölke²,

Schillberg³

et al. 2012

Anal Bioanal Chem

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Fluoroquinolones (FQs) are a group of synthetic, broad-spectrum antibacterial agents. Due to its extensive use in animal industry and aquaculture, residues of these antibiotics and the emergence of bacteria resistant to FQs have become a major public health issue. To prepare a generic antibody capable of recognizing nearly all FQs, a single-chain variable fragment (scFv) was generated from the murine hybridoma cells C49H1 producing a FQ-specific monoclonal antibody. This scFv was characterized by indirect competitive enzyme-linked immunosorbent assay (ciELISA), and it showed identical binding properties to parental monoclonal antibody: it was capable of recognizing 17 of 20 targeted FQs below maximum residue limits, except for sarafloxacin (SAR), difloxacin (DIF), and trovafloxacin (TRO) which are highly concerned members in the FQs family. In order to broaden the specificity of this scFv to SAR and its analogues (DIF and TRO), protein homology modeling and antibody-ligands docking analysis were employed to identify the potential key amino acid residues involved in hapten antibody. A mutagenesis phage display library was generated by site directed mutagenesis randomizing five aminoacid residues in the third heavy-chain complementarity determining region. After one round of panning against biotinylated norfloxacin (NOR) and four rounds of panning against biotinylated SAR, scFv variants we screened showed up to 10-fold improved IC(50) against SAR, DIF, and TRO in ciELISA while the specificity against other FQs was fully retained.

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“…Finally the sorbent was discarded and the elution solvent was analyzed. Therefore, dSPE can be used with the aim of trapping the target analytes which are later eluted or desorbed with an appropriate solvent [33][34][35]. In our study, graphene oxides were used as coating materials for the preparation of graphene oxide-based silica (SiO 2 @GO) microspheres.…”

Section: Introductionmentioning

confidence: 99%

Graphene oxide-based microspheres for the dispersive solid-phase extraction of non-steroidal estrogens from water samples

Wen

Niu

et al. 2014

Journal of Chromatography A

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a b s t r a c tA modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method based on the dispersive solid-phase extraction (dSPE) combined with high performance liquid chromatography (HPLC) was developed for the determination of non-steroidal estrogens in water samples. In this study, graphene oxide-based silica microspheres (SiO 2 @GO) were used as dSPE material for the preconcentration of analytes. HPLC was used for the separation and detection. This was the first time that the synthesized SiO 2 @GO microspheres were used as stationary phases for the off-line preconcentration of the non-steroidal estrogens in dSPE. dSPE parameters, such as sample pH, volume and type of eluent were optimized. Application of the developed method to analyze spiked lake, reservoir and tap water samples resulted in good recoveries values ranging from 70 to 106% with relative standard deviation values lower than 7.0% in all cases. Limits of detection were in the range of 0.2-6.1 g/L. The combined data obtained in this study recommended that the proposed method is very fast, simple, repeatable and accurate for the detection of non-steroidal estrogens. Furthermore, the SiO 2 @GO microspheres application could potentially be expanded to extract and pre-concentrate other compounds in various matrices.

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Oxidized multi-walled carbon nanotubes for the dispersive solid-phase extraction of quinolone antibiotics from water samples using capillary electrophoresis and large volume sample stacking with polarity switching

Cited by 108 publications

References 73 publications

Pesticide residue analysis in cereal-based baby foods using multi-walled carbon nanotubes dispersive solid-phase extraction

Pesticide residue analysis in cereal-based baby foods using multi-walled carbon nanotubes dispersive solid-phase extraction

Improved fluoroquinolone detection in ELISA through engineering of a broad-specific single-chain variable fragment binding simultaneously to 20 fluoroquinolones

Graphene oxide-based microspheres for the dispersive solid-phase extraction of non-steroidal estrogens from water samples

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