Ion balance in waters through inductively coupled plasma optical emission spectrometry

Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) has been employed to carry out the determination of both major anions and cations in water samples. The anion quantification has been performed by means of a new automatic accessory. In this device chloride has been determined by continuously adding a silver nitrate solution. As a result solid silver chloride particles are formed and retained on a nylon filter inserted in the line. The emission intensity is read at a silver characteristic wavelength. By plotting the drop in silver signal versus the chloride concentration, a straight line is obtained. As regards bicarbonate, this anion has been on-line transformed into carbon dioxide with the help of a 2.0 mol L−1 nitric acid stream. Carbon signal is linearly related with bicarbonate concentration. Finally, information about sulfate concentration has been achieved by means of the measurement of sulfur emission intensity. All the steps have been simultaneously and automatically performed. With this setup detection limits have been 1.0, 0.4 and 0.09 mg L−1 for chloride, bicarbonate and sulfate, respectively. Furthermore, it affords good precision with RSD below 6 %. Cation (Ca, Mg, Na and K) concentration, in turn, has been obtained by simultaneously reading the emission intensity at characteristic wavelengths. The obtained limits of detection have been 8 × 10−3, 2 × 10−3, 8 × 10−4 and 10−2 mg L−1 for sodium, potassium, magnesium and calcium, respectively. As regards sample throughput, about 30 samples h−1 can be analysed. Validation results have revealed that the obtained concentrations for these anions are not significantly different as compared to the data provided by conventional methods. Finally, by considering the data for anions and cations, precise ion balances have been obtained for well and mineral water samples.

Cultura médica popular y evolución de la mortalidad: los cuidados de salud en la infancia durante la España contemporánea

Tomando como marco espacial y cronológico la España de finales del XIX y primeras décadas del siglo XX, el trabajo analiza los cuidados prodigados a la infancia en materia de salud, y aborda el estudio de las causas de «orden cultural» que explican el fenómeno del descenso de la mortalidad infantil y juvenil. A partir de la literatura de divulgación higiénico-sanitaria, se exponen algunas de las prácticas y los cuidados que se aplicaban en el ámbito familiar, de forma particular por parte de las madres, para resolver los problemas de salud de los más pequeños.

Las redes sociales en las marcas turísticas de la Comunidad Valenciana

El turismo es uno de los sectores más relevantes de la economía de la Comunidad Valenciana; sin embargo, desde 2009, se produce un importante descenso en la llegada de turistas que motivan la puesta en marcha de diversos planes estratégicos y de competitividad, con propuestas de comunicación en las que resulta fundamental la adaptación a las nuevas tecnologías. En este trabajo se analiza cómo están comunicando, y en qué redes sociales, las principales marcas turísticas de la Comunidad Valenciana: Benidorm, Castellón Mediterráneo, Costa Blanca y València Terra i Mar. Los resultados indican que estas redes se están utilizando más como un canal habitual de promoción y difusión de los productos turísticos, que para el objetivo que las ha hecho populares: la participación e interactividad con el público.

Levels of dioxin-like PCBs in low-volume serum samples of male patients attending fertility clinics

An accurate and easy method for the extraction, cleanup, and HRGC-HRMS analysis of dioxin-like PCBs (DL-PCBs) in low-volume serum samples (1 mL) was developed. Serum samples were extracted several times using n-hexane and purified by acid washing. Recovery rates of labeled congeners ranged from 70 to 110 % and the limits of detection were below 1 pg/g on lipid basis. Although human studies are limited and contradictory, several studies have shown that DL-PCBs can have adverse effects on the male reproductive system. In this way, the present method was applied to 21 serum samples of male patients attending fertility clinics. The total levels obtained for the patients ranged from 6.90 to 84.1 pg WHO-TEQ/g lipid, with a mean value of 20.3 pg WHO-TEQ/g lipid. The predominant PCBs (the sum of PCB 118, 156, and 105) contributed 67 % to the mean concentration of total DL-PCBs in the samples analyzed.