Tipo de bebidas consumidas por los estudiantes universitarios

Fundamentos: Existe una gran diferencia entre el consumo de agua y las bebidas que contiene agua (bebidas carbonatadas, azucaradas, zumos o bebidas alcohólicas). El consumo de estas bebidas está relacionado con el desarrollo de enfermedades crónicas (obesidad, diabetes tipo 2, hipertensión arterial o dislipemias). El objetivo es determinar la frecuencia de consumo de bebidas de los estudiantes de la Universidad de Alicante. Métodos: Estudio transversal descriptivo. Población 26.273 estudiantes. Se seleccionaron 396 mediante muestreo aleatorio simple. Se utilizó un cuestionario frecuencia consumo para estimar la ingesta individual. Variables: bebidas (n=12) y frecuencia de consumo (n=4). Resultados: El 29,6% de hombres y el 13,0% de mujeres consumen bebidas carbonatadas con azúcar a diario (p-valor<0,001). El consumo diario de vino es nulo. El 41,4% de la población consume cerveza y destilados semanalmente. El 76,1% de hombres y el 58,7% de mujeres, consumen alcohol como mínimo una vez a la semana, p-valor=0,001. Conclusiones: Los resultados plantean la necesidad de estudios epidemiológicos que orienten el desarrollo de políticas nutricionales dirigidas a reducir el consumo de bebidas azucaradas y alcohólicas entre la población joven. Mediante un trabajo conjunto entre las autoridades gubernamentales, medios de comunicación, industria alimentaria y la sociedad en general.

On-line microwave-based preconcentration device for inductively coupled plasma atomic emission spectrometry: Application to the elemental analysis of spirit samples

A microwave-based thermal nebulizer (MWTN) has been employed for the first time as on-line preconcentration device in inductively coupled plasma atomic emission spectrometry (ICP-AES). By the appropriate selection of the experimental conditions, the MWTN could be either operated as a conventional thermal nebulizer or as on-line analyte preconcentration and nebulization device. Thus, when operating at microwave power values above 100 W and highly concentrated alcohol solutions, the amount of energy per solvent mass liquid unit (EMR) is high enough to completely evaporate the solvent inside the system and, as a consequence, the analyte is deposited (and then preconcentrated) on the inner walls of the MWTN capillary. When reducing the EMR to the appropriate value (e.g., by reducing the microwave power at a constant sample uptake rate) the retained analyte is swept along by the liquid-gas stream and an analyte-enriched aerosol is generated and next introduced into the plasma cell. Emission signals obtained with the MWTN operating in preconcentration-nebulization mode improved when increasing preconcentration time and sample uptake rate as well as when decreasing the nozzle inner diameter. When running with pure ethanol solution at its optimum experimental conditions, the MWTN in preconcentration-nebulization mode afforded limits of detection up to one order of magnitude lowers than those obtained operating the MWTN exclusively as a nebulizer. To validate the method, the multi-element analysis (i.e. Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Pb and Zn) of different commercial spirit samples in ICP-AES has been performed. Analyte recoveries for all the elements studied ranged between 93% and 107% and the dynamic linear range covered up to 4 orders of magnitude (i.e. from 0.1 to 1000 μg L−1). In these analysis, both MWTN operating modes afforded similar results. Nevertheless, the preconcentration-nebulization mode permits to determine a higher number of analytes due to its higher detection capabilities.