Chromium occurrence in the environment and methods of its speciation.

Sequential selective extraction techniques are commonly used to fractionate the solid-phase forms of metals in soils. Many sequential extraction procedures have been developed, particularly for sediments or agricultural soils, and, despite numerous criticisms, they remain very useful. This article reviews the reagents used in the various schemes, with their advantages and disadvantages. The particular case of elements giving anionic species is also developed. Finally, there is discussion of the limits of sequential extraction procedures.

Fractionation studies of trace elements in contaminated soils and sediments: a review of sequential extraction procedures

http://projects.itn.pt/UCQR_QAA/Morrilo_et_al_%202004.pdf

Heavy metal distribution in marine sediments from the southwest coast of Spain

Selenium (Se) is an essential micronutrient for humans and animals, but lead to toxicity when taken in excessive amounts. Plants are the main source of dietary Se, but essentiality of Se for plants is still controversial. However, Se at low doses protects the plants from variety of abiotic stresses such as cold, drought, desiccation and metal stress. In animals, Se acts as an antioxidant and helps in reproduction, immune responses, thyroid hormone metabolism. Selenium is chemically similar to sulfur, hence taken up inside the plants via sulfur transporters present inside root plasma membrane, metabolized via sulfur assimilatory pathway, and volatilized into atmosphere. Selenium induced oxidative stress, distorted protein structure and function, are the main causes of Se toxicity in plants at high doses. Plants can play vital role in overcoming Se deficiency and Se toxicity in different regions of the world, hence, detailed mechanism of Se metabolism inside the plants is necessary for designing effective Se phytoremediation and biofortification strategies.

/pdf/an-overview-of-selenium-uptake-metabolism-and-toxicity-in-2dcl7xb0v2.pdf

An Overview of Selenium Uptake, Metabolism, and Toxicity in Plants.

We review recent research in the field of arsenic speciation analysis with the emphasis on significant advances, novel applications and current uncertainties.

Determination of arsenic species: A critical review of methods and applications, 2000–2003

Children's fast food menus, including hamburgers served with french fries, dessert, and a soft drink, were analyzed to obtain the mineral profile of trace elements The developed analytical methodology involved sample digestion under pressure inside a microwave oven with a mixture of HNO3 and H2O2 and inductively coupled plasma-optical emission spectrometry The method was validated by carrying out the analysis of certified reference materials (NIST 1570a spinach leaves, NCS ZC73016 chicken, and NIST 1568a rice flour) and using recovery experiments Repeatability was verified by analyzing replicate samples Twenty-six elements were studied, 12 of which-aluminum, barium, calcium, copper, iron, potassium, lithium, magnesium, manganese, sodium, strontium, and zinc-were quantitatively determined Results were compared with other studies of fast food and children's menus published in the literature, and the nutritional value of samples was assessed with dietary intake guidelines

Mineral Profile of Children's Fast Food Menu Samples.

Summary
A nonchromatographic analytical procedure has been developed for the determination of arsenic in meat samples including the major toxic arsenic species arsenite, arsenate, monomethylarsonic acid (MMA) and dimetylarsinic acid (DMA). The method is based on the extraction of arsenic species in mild conditions, selective trivalent hydride formation and final determination by hydride generation atomic fluorescence spectroscopy (HG-AFS). Different extractant agents and two different procedures, microwave-assisted extraction (MAE) and ultrasound assisted extraction at room temperature, were evaluated for As species extraction. The method provided a limit of detection of 0.013 ng mL−1 and a mean relative standard deviation in actual samples of 0.3%. Data found for toxic As in meat samples varied from 0.42 ng g−1 in chicken muscle to 68 ng g−1 in pork liver. Percentage of toxic As respect to total As varied in the 9–46% range depending on the meat product.

Fast extraction methodologies for the determination of toxic arsenic in meat

Is lithium implicated in tobacco addiction

Analysis of the Mineral Composition of Tannery Solid Wastes: The Case of Wet-Blue Chrome Shavings

We present the activities of the Innocampus Explora innovation project developed on the Burjassot-Paterna campus of the Universitat de València and whose main objective is to show the interrelation between the different scientific and technical degrees on campus. In this year, the work team made up of students and professors from all the faculties and schools of the BurjassotPaterna campus, have carried out activities around environmental issues. A cross-sectional and interdisciplinary vision of the problems of the uses of plastic and nuclear energy that link with several of the Sustainable Development Goals (SDGs) dictated by the United Nations. With the development of this project we contribute to quality transversal training for all participating students.

/pdf/innocampus-explora-una-aproximacion-multidisciplinar-a-la-4tord2m195.pdf

Maria Luisa Cervera

Papers

Mineral Profile of Children's Fast Food Menu Samples.

Fast extraction methodologies for the determination of toxic arsenic in meat

Is lithium implicated in tobacco addiction

Analysis of the Mineral Composition of Tannery Solid Wastes: The Case of Wet-Blue Chrome Shavings

Innocampus Explora: una aproximación multidisciplinar a la problemática ambiental