Person: Martín Carmona, María Antonia
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First Name
María Antonia
Last Name
Martín Carmona
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Farmacia
Department
Química en Ciencias Farmacéuticas
Area
Química Analítica
Identifiers
3 results
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Item Eco-friendly liquid chromatographic separations based on the use of cyclodextrins as mobile phase additives(Green Chemistry, 2011) González Ruiz, Víctor; León Leal, Andrés Gerardo; Menéndez Ramos, José Carlos; Martín Carmona, María Antonia; Olives Barba, Ana IsabelAcetonitrile and methanol are the most popular solvents employed in analytical HPLC, but they suffer from a number of drawbacks from the environmental point of view. Alternative, greener mobile phases employing methanol or the less toxic solvent ethanol as the sole organic solvent are proposed in this paper, and applied to the problem of the separation of b-carbolines on C18-stationary phases. The use of b-cyclodextrin (b-CD) and (2-hydroxypropyl)-b-cyclodextrin (HPb-CD) as mobile phase additives allowed us to increase the proportion of water in the mobile phases without loss in the resolution or efficiency of the separations, leading initially to a considerable reduction of the proportion of methanol in the mobile phase (from 70% to 50%) and at a later stage, to the development of a mobile phase containing only 30% of ethanol. The b-carboline–cyclodextrin association constants were determined by HPLC, and the inclusion complexes were also characterized by 1 H-NMR, 13C-NMR and 2D-ROESY experiments, and these studies were used to explain the chromatographic behaviour. The new chromatographic methodology developed was validated and applied to the quantitation of b-carboline derivatives in spiked human serum samples. For the extraction of b-carboline alkaloids from serum samples, liquid–liquid extraction (LLE) and solid-phase extraction (SPE) procedures were compared. It was concluded that the combination of a pre-treatment procedure (ionic exchange SPE) with a water-enriched chromatographic separation leads to a promising, environmentally friendly new methodology.Item An Easily Built Smoking Machine for Use by Undergraduate Students in the Determination of Total Particulate Matter and Nicotine in Tobacco Smoke(Journal of Chemical Education, 2012) González Ruiz, Víctor; Martín Carmona, María Antonia; Olives Barba, Ana IsabelSampling mainstream cigarette smoke is a challenging and stimulating laboratory activity for undergraduate students. In addition to the public health significance, cigarette smoke is an unusual source of analytes to examine the differences between gaseous matrices versus liquid or solid matrices. Sophisticated automated smoking machines complying with international standards are not affordable for educational purposes. However, a less expensive and simple smoking apparatus can be easily built in any laboratory that yields reproducible smoking conditions and allows several cigarettes to be smoked simultaneously. We describe the construction of such an apparatus utilizing a solid-phase extraction manifold and chamber, and how it can be used by undergraduate students to generate cigarette smoke and trap the total particulate matter (TPM). The TPM can be later gravimetrically quantified and eluted with 2-propanol containing an internal standard to quantify th nicotine content. Because a set of six cigarettes can be “smoked” simultaneously, the proposed procedure allows the comparison of TPM and nicotine content in mainstream smoke from normal and light cigarettesItem A down-scaled fluorimetric determination of the solubility properties of drugs to minimize waste generation(Green Chemistry, 2013) González Ruiz, Víctor; Olives Barba, Ana Isabel; Martín Carmona, María AntoniaA miniaturized fluorescence assay on multi-well plates has been developed to study the solubility enhancement effect of (2-hydroxypropyl)-β-cyclodextrin on three anti-tumor alkaloids. The measurement of the fluorescence emission on a multi-well plate format has been proved to be a rapid and efficient technique to evaluate the solubility of pharmaceutical formulations of new drugs that help save time, reagents and wastes in the search for greener analytical strategies. The proposed methodology was compared with a reference HPLC solubility study and was employed to examine the enhancement of the solubility of camptothecin, luotonin A, and a synthetic derivative of the latter in the presence of (2-hydroxypropyl)-β-cyclodextrin. Considerable reductions in the time of analysis (almost 50 times faster) and the volume of organic solvents employed (close to 25 times less acetonitrile needed) were achieved. The nature of the inclusion complexes was investigated by analysis of the phase-solubility diagrams obtained by the newly developed method and was complemented with spectrofluorimetry and ESI-MS experiments. The concentrations of solubilised compounds found by both methodologies were in good agreement (R2 > 0.98). The analytical figures of merit of both methodologies were compared and the adequacy of the proposed method for the development of drug solubilisation studies was discussed.s.