Microelements

CONTROLLING PRECISION OF ATOMIC-EMISSION MICROELEMENT ANALYSIS IN SOILS BASED ON APPLIED... 

The AEA results for Zn, Ag, Ge, Tl, B, Co, Cr, Ga, Ni, Sr, Sc, Ba in GSS series satisfy the criteria of quality proposed. This allows to believe that the values of microelements contents in soils under conditions of the methods applied for quantitative AEA ai e quite reliable. 

DETERMINATION OF MACRO- AND MICROELEMENTS IN BIOLOGICAL SAMPLES BY ATOMIC SPECTRAL METHODS... 

Selenium is a vital microelement for people. It has dual properties. Selenium is an essential nutrient at low concentration levels and it becomes toxic at higher concentration levels. Deficiency of selenium results in weakness and hard diseases. Selenium is a building material of many hormones and ferments it neutralizes free radicals, radioactive radicals in organism. The range of selenium safety concentration in food and water is very narrow. The daily normal amount of human consumption of selenium is 10-20 p.g, maximum safe concentration of selenium in water is 5-10 p.g/1. It becomes toxic at 20-30 p.g and bigger content in different objects. 

The aim of the investigation was to study the influence of calcium and sodium ions, pectin containing extracts of aromatic vegetative raw materials and mumio on the carbopol gelation to develop the procedure of calcium and sodium ions mass part determination in extracts of aromatic vegetative pectin containing raw materials to establish the macro- and microelement composition of mumio. 

The determined macro- and microelement stmcture of mumio specifies onto the expediency of the application of this biologically active substance as a cosmetic raw material in the cosmetic compositions, which do not contain carbopol. The developed procedure for calcium and sodium ions determination in pectin-containing vegetative extracts is express and it is recommended for application at elaboration of cosmetic production compositions on the carbopol base. 

Johansson, S., "Fracture Testing of Silicon Microelements In Situ in a Scanning Electron Microscope, 7. Appl. Phys., Vol. 63,1988,pp. 4799 808. 

Arnon DI (1938) Microelements in culture-solution experiments with higher plants. Am J Bot 25 322-325. 

M. Shenker, Y. Hadar, and Y. Chen, Stability constants of the fungal siderophore rhizoferrin with various microelements and calcium. Soil Sci. Soc. Ain. J. 60 1140 (1996). 

Chojnacka, K., Biosorption and bioaccumulation of microelements by Riccia fluitans in single and multi-metal system, Bioresource Technology, 98 (15), 2919-2925, 2007. 

Pesticides affect the content of microelements and other substances in plants, thus changing their nutritive value, as well as their ability to be stored. This was detected for OCPs in grain and legume harvests. For example, wheat crops treated with some fungicides (zineb, bayleton, and propicanazol) to fight stem rust (Puccirda) produce a lower quality of bread [3]. 

Shuman L.M. Fractionation method for soil microelements. Soil Sci 1985a 140 11-22. 

Shuman L.M., Separating soil iron- and manganese-oxide fractions for microelement analysis, Soil Sci Soc Am J 1982 46 1099-1102. 

Various forms of macro- and microelements differ in their ability to migrate and redistribute among the soil profile. The elements contained in clastic minerals are practically immobile. The elements, bound to finely dispersed clay minerals, are either co-transported with clay particles, or are involved in sorption-desorption processes. Part of the elements are found in concretions and also in very thin coating films of hydrated iron oxides some elements make a part of specially edaphic organic compounds. 

The biogeochemical mass budget of various macro- and microelements for this catchment is shown in Table 4. 

The biogeochemical fluxes and exposure pathways of various macro- and microelements are different from those shown for Tropical Rain Forest ecosystems. The chemical composition of leaves of tree species in Mangrove Forest ecosystems is connected with higher content of Mg, Cl and S-SO4- and lesser content of K and Si as compared to the leaves of trees from Tropical Rain Forest ecosystems. The content of A1 is 3-4 times higher than that of Si and this can be related to the values of hydrogenic accumulation of these elements in soils (Figure 3). 

Efendiev, F. M. Combined spectral and chemical analysis of microelements. 

Determination of the roles of microelements and the human daily requirements can be very difficult due to their low concentrations in the human body and problems connected with the elimination of their constant inflow. Throughout the evolution process, the human body developed mechanisms to regulate the absorption of microelements and balance their levels within required ranges. Therefore, human bodies are adjusted to the natural levels at which those elements are present in the non-polluted environment and in non-contaminated foodstuffs. However, human industrial and economic activities are frequently and widely disturbing the environmental balance and leading to contamination of the environment, including foods, with trace elements. 

Zinc is a microelement essential for proper functioning of the human body. The level of daily demand for zinc was established as 13 to 16 mg (Ziemlahski, 2001). Zinc plays a role in protein and carbohydrate metabolism and is a component of over 60 metaloenzymes, including alkaline phosphatase, pancreatic carboxypeptidases A and B, alcoholic and lactic dehydrogenases, carbonate anhydrase, and proteases. It also forms bonds with nucleic acids -which is very important for their functioning (Prasad, 1983 Valee and Falchuk, 1993). 

The Grinization complexes include all vitally needed macro-, micro-and ultra-microelements that are compulsory components of the animal and vegetable matter being their source used in Grinization complexes production. With the scope of the Grinization complexes, functional activity increase, and some essential macro- and microelements are added, such as calcium, magnesium, zinc, manganese, silicium, vanadium these are included into the complexes in the most solvable and acceptable form of chelates. 

Heinold, D. Smith, D. Finding the weak links. Environ. Protection 2003, 14 (2), 56-65. Munshower, F.F. Microelements and their role in surface mine planning. In Coal Development Collected Papers, Volume IT, Coal Development Workshops in Grand Junction, Colorado and Casper, Wyoming, Bureau of Land Management, July 1983. 

The elements essential for life can be divided into macroelements (daily requirement > 100 mg) and microelements (daily requirement < 100 mg). The macroelements include the electrolytes sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg), and the nonmetals chlorine (Cl), phosphorus (P), sulfur (S), and iodine (I). 

The essential microelements are only required in trace amounts (see also p.2). This group includes iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), cobalt (Co), chromium (Cr), selenium (Se), and molybdenum (Mo). Fluorine (F) is not essential for life, but does promote healthy bones and teeth. It is still a matter of controversy whether vanadium, nickel, tin, boron, and silicon also belong to the essential trace elements. 

Thermal and mass flow-through sensors rely on differential measurements owing to the low selectivity of these types of detection. They use two flow-cells arranged in series (Fig. 2.9.B) or parallel (Fig. 2.9.C), each containing a sensitive microelement (a piezoelectric crystal or a thermistor). One of the cells houses the sensitive microzone, whereas the other is empty or accommodates an inert support containing no immobilized reagent (e.g. see [35]). 

Pets, L. Haldna, U. 1995. Microelements in Estonian and Green River (USA) oil shales a quantitative comparison. Oil Shale, 12, 239- 245. 

Engelhard, A.W. (ed.) 1989. Soilborne Plant Pathogens Management of Diseases with Macro-and Microelements. APS Press, St Paul. 

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