Ultrasound-assisted extraction for rapid determination of Zn, Cu, Fe, Mg and Mn in liver of diabetic rats under different antioxidant treatments.

The metabolism of several essential elements is altered in diabetes mellitus and these nutrients might have specific roles in the pathogenesis and progress of this disease, nevertheless, the mechanisms are still far from known. Variations in Zn, Cu, Fe, Mg and Mn in rat liver have been measured both in control and diabetic rats which have been given antioxidants (either synthetic or natural extracts) or a placebo. Classical contaminant and time-consuming digestion methods for sample pre-treatment have been substituted by ultrasound-assisted liquid extraction (USLE). The effect of several parameters was studied, the best results being obtained for: 0.2 g of sample in 10 mL 10% HNO(3) and 8 min of sonication with 19 kHz frequency. The complete analytical method was validated regarding linearity, precision, accuracy and limits of detection (LOD) and quantification (LOQ). Values for LOD ranged from 0.6 for Mn to 12.5 for Mg, and LOQ ranged from 1.8 for Mn and to 62.5 for Mg expressed as microg g(-1) in sample. Results showed an increase of all the metal assayed in the liver of diabetic rats as compared to controls. Nevertheless, when animals were treated either with antioxidants or Dunaliella extracts in a short term assay, Fe increase in liver of diabetic rats was lower than with the other treatments, while Rosmarinus (rosemary) extracts were the only treatment producing a decrease in Mn on diabetic rats.

Validated flow-injection method for rapid aluminium determination in anti-perspirants.

A flow-injection (FI) method for the rapid determination of aluminium in anti-perspirants has been developed. The method is based on the spectrophotometric detection at 535nm of the complex formed between Al ions and the chromogenic reagent eriochrome cyanine R. Both the batch and FI methods were validated by checking the parameters included in the ISO-3543-1 regulation. Variables involved in the FI method were optimized by using appropriate statistical tools. The method does not exhibit interference from other substances present in anti-perspirants and it shows a high precision with a R.S.D. value (n=6) of 0.9%. Moreover, the accuracy of the method was evaluated by comparison with a back complexometric titration method, which is currently used for routine analysis in pharmaceutical laboratories. The Student's t-test showed that the results obtained by both methods were not significantly different for a significance level of 95%. A response time of 12s and a sample analysis time, by performing triplicate injections, of 60s were achieved. The analytical figures of merit make the method highly appropriate to substitute the time-consuming complexometric method for this kind of analysis.

Capillary electrophoresis for short chain organic acids in faeces Reference values in a Mediterranean elderly population.

There is increasing evidence that gut microflora and fermentation processes in the large intestine are important for health, and that health-promoting effects are mediated by fermentation products. Usually analytical methods for these compounds are tedious. A simple and rapid procedure of aqueous extraction from the stools has been optimized. After extraction, an aliquot of the aqueous layer was directly injected into the capillary electrophoresis equipment. Oxalic, formic, fumaric, 2-ketoglutaric, succinic, citric, acetic, propionic, 2-ketoisovaleryc, butyric, isovaleric lactic, glyceric 2-hydroxybutyric, and valeric acids were separated and identified. Electrophoretic conditions were: phosphate buffer 234 mM pH 6.10 with 12% (v/v) methanol with a coated capillary at -10 kV of applied potential. The method was validated for a representative group of compounds: acetic, propionic butyric, 2-hydroxybutiric, isovaleric, and oxalic acids, including the comparison of results with ionic chromatography. Finally 136 samples from healthy humans aged 60-80, both male and female living in Spain, were measured. They could be used as reference values for further studies.

Estudio de la disolución del calcio a partir de una nueva formulación de comprimidos bucodispersables y su comparación con formulaciones masticables convencionales / Study of the dissolution of calcium contained in a novel orodispersible tablet formulation and its comparison with conventional chewable formulations

Los suplementos de calcio con vitamina D constituyen un componente habitual de los tratamientos de la osteoporosis. La absorción del calcio suministrado requiere su disolución previa. Sin embargo, las sales de calcio habitualmente utilizadas son muy poco solubles y dependen del ácido gástrico para liberar el calcio en forma biodisponible. Se ha desarrollado una nueva formulación bucodispersable de calcio y vitamina D (Natecal D Flas). Esta formulación no sólo facilita el cumplimiento terapéutico del tratamiento, sino también la disolución del calcio y, por tanto, su biodisponibilidad. En este estudio se ha comparado la disolución del calcio de comprimidos masticables convencionales con la nueva formulación bucodispersable, tanto en medio gástrico artificial (pH ácido) como en agua (ausencia de ácido). Los resultados indican que en medio gástrico artificial, simulando condiciones fisiológicamente normales, los comprimidos bucodispersables producen una disolución significativamente más rápida del calcio que los comprimidos masticables. En el caso del agua, simulando una condición de aclorhidria absoluta, no se produce disolución del calcio en el caso de los comprimidos masticables mientras que existe una disolución parcial, pero significativa, en el caso de los comprimidos bucodispersables. Estos resultados indican que la nueva formulación bucodispersables de carbonato cálcico y vitamina D (Natecal D Flas) contribuye a una mejor absorción del calcio en aquellos pacientes en la que ésta puede estar disminuida por circunstancias fisiológicas (AU)

Calcium supplements with vitamin D are standard components of treatments for osteoporosis. The absorption of the calcium provided requires its prior dissolution. However, the solubility of the calcium salts usually employed is limited and the release of the calcium in a bioavailable form depends on gastric acid. A novel orodispensible formulation of calcium and vitamin D (Natecal D Flas) has been developed. This formulation not only facilitates treatment compliance, but the dissolution of the calcium as well, thus enhancing its bioavailability. In this study, the authors have compared the dissolution of the calcium contained in conventional chewable tablets with that of the new orodispersible formulation, both in artificial gastric juice (acidic pH) and in water (absence of acid). The results indicate that, in artificial gastric juice, simulating normal physiological conditions, the orodispersible tablets produce a significantly more rapid dissolution of calcium than the chewable tablets. In the case of water, simulating conditions of absolute achlorhydria, there is no dissolution of the calcium contained in the chewable tablets, whereas partial, but significant, dissolution is observed with the orodispersible tablets. These findings indicate that the novel orodispersible formulation of calcium carbonate and vitamin D (Natecal D Flas) contributes to better absorption of calcium in those patients in whom this process may be compromised by physiological circumstances (AU)

Uptake and distribution of zinc, cadmium, lead and copper in Brassica napus var. oleífera and Helianthus annus grown in contaminated soils.

Brassica napus var. oleifera and Helianthus annus were grown in artificially contaminated soils. Accumulation and translocation of the environmental pollutants zinc, cadmium, lead, and copper, was evaluated in different portions of the plants at two harvesting times. The distribution into the plants of these metal ions, as well as their capacity for contaminant phytoextraction and accumulation was assessed. For this purpose, an analytical method utilizing focused ultrasound employed for extraction and stripping voltammetry for measurement has been optimized and validated for the simultaneous measurement of Zn, Cd, Pb, and Cu in plant extracts.