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- Feás, Xesús, et al.
(författare)
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Application of dummy molecularly imprinted solid-phase extraction in the analysis of cyproheptadine in bovine urine.
- 2009
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Ingår i: Journal of Separation Science. - : Wiley. - 1615-9314 .- 1615-9306. ; 32:10, s. 1740-1747
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Tidskriftsartikel (refereegranskat)abstract
- Due to the difficulty of monitoring trace levels of cyproheptadine (CYP) residues in complicated biological matrices, specific adsorption materials for the preconcentration and clean-up of CYP are indispensable. In this work, CYP was extracted from urine using dummy molecularly imprinted SPE (DMISPE) to avoid leakage of the imprinting molecules during the desorption phase. For synthesis of DMISPE, azatadine (AZA) was employed as the dummy template, methacrylic acid (MAA) as the monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,2'-azobis(2-methylpropionitrile) (AIBN) as the initiator, and dichloromethane as the porogen solvent. An LC-MS/MS method was used to analyze CYP. Two MRM (multiple reaction monitoring) transitions for each analyte were monitored using diphenylpyraline hydrochloride (DPP.HCl), which was used as an internal standard. The advantages of DMISPE include obtaining less complex chromatograms and reducing ion suppression in ESI. The process efficiencies for DMISPE and SPE were 80% and 12%, respectively. In addition, the demonstrated reusability of the DMISPE cartridges is an advantage compared with single-use SPE cartridges or immunoaffinity materials.
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| 2. |
- Feás, Xesús, et al.
(författare)
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Development and validation of LC-MS/MS method for the determination of cyproheptadine in several pharmaceutical syrup formulations.
- 2009
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Ingår i: Journal of Pharmaceutical and Biomedical Analysis. - : Elsevier BV. - 0731-7085. ; 50, s. 1044-1049
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Tidskriftsartikel (refereegranskat)abstract
- A rapid and sensitive liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the qualitative and quantitative assay of cyproheptadine (CP) in pharmaceutical samples. Diphenylpyraline hydrochloride (DPP) was used as an internal standard (IS). Two multiple reaction-monitoring (MRM) transitions for each analyte were observed: 288.1/96.1 and 288.1/191.2 for CP and 282.1/167.2 and 282.1/116.3 for DPP. The retention time of the drug was 7.29min. The analytical method was successfully validated for linearity (1-100ng/ml), intra-day precision, inter-day precision, and accuracy. The limit of detection (LOD) and limit of quantification (LOQ) were 0.86 and 0.98ng/ml, respectively. The proposed method was applied to analyse the cyproheptadine content from seven different syrup formulations.
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| 3. |
- Feas, Xesus, et al.
(författare)
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Molecularly imprinted polyallylamine hydrogels: another reassessment
- 2010
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Ingår i: Polymer International. - : Wiley. - 0959-8103. ; 59:1, s. 11-15
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Tidskriftsartikel (refereegranskat)abstract
- Researchers in the scientific community actively discuss the fact that polymer hydrogels synthesized by crosslinking polly(allylamine hydrochloride) (PAH) with epichlorohydrin (EPI) in the presence of D-glucose-6-phosphate monobarium salt do not show or show imprinting on the molecular level. In the work reported here, a polymer hydrogel was synthesized in the presence of flumequine (FQ) by crosslinking PAH with EPI in an aqueous system. The extent of FQ binding was assessed using liquid chromatography coupled with laser-induced fluorescence detection. A hydrogel-imprinting system was found to display FQ selectivity in binding assays (75.1 and 41.9%) compared with hydrogel formed in the absence of a template (41.6 and 20.4%). High-magnification scanning electron microscopy (SEM) images show that both of the hydrogels are highly ordered, exhibiting a 'honeycomb' pattern distribution. For the effect of the template molecule in the polymer structure (i.e. the imprinting effect in hydrogel morphology), appreciable differences were observed for images obtained. The non-imprinted polymer had a uniform, smoothly shaped surface. By contrast, the hydrogel molecular imprinting polymer surface was more globular. This difference was likely caused by the structure of the target molecule. Binding experiment results correlate with surface morphology, as analysed using SEM, and indicate that imprinted hydrogels have recognizable cavities with an affinity for used FQ from the imprint. (C) 2009 Society of Chemical Industry
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