Examinando por Autor "Sierra, Isabel"

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  • Miniatura
    Publicación
    Determination of atropine and scopolamine in honey using a miniaturized polymer-based solid-phase extraction protocol prior to the analysis by HPLC-MS/MS
    (Elsevier, 2024-04-09) Fernández Pintor, Begoña; Gañán Aceituno, Judith; Morante Zarcero, Sonia; Sierra, Isabel; Paniagua González, Gema; Fernández Hernando, Pilar; Garcinuño Martínez, Rosa Mª
    Two homopolymers have been prepared employing methacrylic acid and 4-vynylpiridine as functional monomers (p-MAA, p-4-VP) through an easy and quick precipitation polymerization method for application as sorbents in solid-phase extraction (SPE) to determine atropine and scopolamine in honey. The optimized SPE conditions were as follows: 25 mg of p-MAA, 4 mL of sample loading volume (diluted honey 1:10 with water), 4 mL of elution solvent (methanol/water with 1 % formic acid, 80/20, v/v). The extracts were analyzed by HPLC-MS/MS. The cartridges were reusable for forty cycles demonstrating an environmentally friendly approach. The methodology was validated in terms of linearity, accuracy, precision, selectivity, matrix effect and sensibility, highlighting the absence of matrix effect. The miniaturized polymer-based SPE was successfully applied to fifteen honeys, showing concentrations up to 7.23 ng/g in the most contaminated honey. All quantified honey samples (5 in total) were of multifloral type.
  • Miniatura
    Publicación
    Fibreglass membrane chemically modified with amino-functionalised SBA-15 and its application in solid-phase extraction to determine macrolide antibiotics in eggs
    (Elsevier, 2024-10) González Gómez, Lorena; Morante Zarcero, Sonia; Pérez Quintanilla, Damián; Paniagua González, Gema; Garcinuño Martínez, Rosa Mª; Fernández Hernando, Pilar; Sierra, Isabel
    Macrolides are a group of high-spectrum antibiotics used to treat animal ailments, sometimes these drugs can appear as residues in animal foods such as eggs, which must be controlled as required by the European Union. Therefore, in this paper a methodology based on solid–liquid extraction followed on the application of a new membrane-solid-phase extraction (membrane-SPE) was developed and validated for the extraction and purification of five macrolide antibiotics such as spiramycin (SPI), erythromycin (ERY), roxithromycin (ROX), josamycin (JOS) and tylosin (TYL), in egg samples for their analysis by high-performance liquid chromatography coupled to mass spectrometry analysis (HPLC-MS/MS). The newly synthesised membrane-based sorbent consisted of a fibreglass membrane chemically modified with silica SBA-15 type functionalised with amino groups (FGM-SBA-15-NH2). The optimal conditions for membrane-SPE on eggs were determined using a three-factor, three-level Box Behnken design (BBD). The conditions obtained were by loading with 4 mL of water and eluting with 3 × 2.5 mL of MeOH with ammonia solution (0.5 %, v/v). The methodology was validated according to Regulation (EU) 2021/808 showing good selectivity, linearity (R2 ≥ 0.993), low limits (MQL 1.1–2.1 ng/g, MDL 0.3–0.6 ng/g), acceptable decision limit for confirmation (CCα), good accuracy (recoveries 85–100 %) and an adequate precision (RSD ≤ 16 %). The FGM-SBA-15-NH2 proved to be reproducible in different batches and reusable around 70 times. Finally, the validated method was successfully applied to fourteen egg samples detecting SPI in one hen egg sample and JOS and ROX in one quail egg sample. The proposed methodology introduces a groundbreaking membrane-SPE approach, addressing limitations in conventional SPE methods. The use of functionalised silica to chemically modify FGM significantly improves its textural properties, allowing the simultaneous extraction and purification of macrolide antibiotics from egg samples.