Trace element Manganese Molybdenum Nickel

Nixon277 compared atomic absorption spectroscopy, flame photometry, mass spectroscopy, and neutron activation analysis as methods for the determination of some 21 trace elements (<100 ppm) in hard dental tissue and dental plaque silver, aluminum, arsenic, gold, barium, chromium, copper, fluoride, iron, lithium, manganese, molybdenum, nickel, lead, rubidium, antimony, selenium, tin, strontium, vanadium, and zinc. Brunelle 278) also described procedures for the determination of about 20 elements in soil using a combination of atomic absorption spectroscopy and neutron activation analysis. 

Coal contains several elements whose individual concentrations are generally less than 0.01%. These elements are commonly and collectively referred to as trace elements. These elements occur primarily as part of the mineral matter in coal. Hence, there is another standard test method for determination of major and minor elements in coal ash by ICP-atomic emission spectrometry, inductively coupled plasma mass spectrometry, and graphite furnace atomic absorption spectrometry (ASTM D-6357). The test methods pertain to the determination of antimony, arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, molybdenum, nickel, vanadium, and zinc (as well as other trace elements) in coal ash. 

Mitchell [296] has published data for the trace-element contents of red clover and ryegrass grown on 15 different soils in north-east Scotland and the variations in the levels of copper, manganese, molybdenum, nickel and zinc are less than sevenfold. The variation in copper and zinc levels in both plant species is actually less than twofold and it is clear that plants have some capacity to regulate their uptake of trace elements and that the main effect is to damp down the consequences of variation in concentration in soil solutions, so that the range of uptake of most elements is restricted. Availability in soil appears to be as much a plant function as a physico-chemical soil property. 

Cobalt, copper, molybdenum, iodine, iron, manganese, nickel, selenium, and zinc are sometimes provided to mminants. Mineral deficiency or toxicity in sheep, especially copper and selenium, is a common example of dietary mineral imbalance (21). Other elements may be required for optimal mminant performance (22). ExceUent reviews of trace elements are available (5,22). 

In addition to carbon and hydrogen, the key elements in the molecules of life include nitrogen, oxygen, phosphorus, and sulfur. Also, a family of trace elements is required sodium, potassium, magnesium, manganese, calcium, chlorine, fluorine, iodine, iron, copper, nickel, cobalt, zinc, molybdenum, silicon and vanadium. 

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. 

An enzyme cofactor can be either an inorganic ion (usually a metal cation) or a small organic molecule called a coenzyme. In fact, the requirement of many enzymes for metal-ion cofactors is the main reason behind our dietary need for trace minerals. Iron, zinc, copper, manganese, molybdenum, cobalt, nickel, and selenium are all essential trace elements that function as enzyme cofactors. A large number of different organic molecules also serve as coenzymes. Often, although not always, the coenzyme is a vitamin. Thiamine (vitamin Bj), for example, is a coenzyme required in the metabolism of carbohydrates. 

Mertz DP, Koschnick R, Wilk G, et al. 1968. [Studies on the metabolism of trace elements in humans. I. Serum values for cobalt, nickel, silver, cadmium, chromium, molybdenum, manganese],... 

Some elements are essential to the composition or function of the body. Since the body is mostly water, hydrogen and oxygen are obviously essential elements. Carbon (C) is a component of all life molecules, including proteins, lipids, and carbohydrates. Nitrogen (N) is in all proteins. The other essential nonmetals are phosphorus (P), sulfur (S), chlorine (Cl), selenium (Se), fluorine (F), and iodine (I). The latter two are among the essential trace elements that are required in only small quantities, particularly as constituents of enzymes or as cofactors (nonprotein species essential for enzyme function). The metals present in macro amounts in the body are sodium (Na), potassium (K), and calcium (Ca). Essential trace elements are chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), magnesium (Mg), molybdenum (Mo), nickel (Ni), and perhaps more elements that have not yet been established as essential. 

Originally, nine of the trace elements were considered to be essential to humans cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, selenium, and zinc. Recently, chromium, silicon, and nickel have been added to this list (Reilly 1996). These are mostly metals some are metalloids. In addition to essential trace elements, several trace elements have no known essentiality and... 

In contrast, the remaining trace elements of nutritional interest are silicon, vanadium, chromium, manganese, nickel, arsenic, selenium, molybdenum, tin, and perhaps cadmium. These elements present serious problems of analysis in the concentration range that is of interest to the nutritionist. Only a few specialized laboratories have developed expertise... 

Purified diets analysed over many years have indicated that the following elements are found in our diet oxygen, carbon, nitrogen, calcium, magnesium, phosphorus, iron, sodium, potassium, chlorine, sulfur, iodine, zinc, copper, selenium, manganese, molybdenum, vanadium, fluorine, cobalt, chromium, nickel, silica, aluminium, tin, and possibly traces of arsenic, are essential or beneficial to human health. 

The elements beryllium, magnesium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, zinc, zirconium, molybdenum, silver, cadmium, tin, thallium, lead, and bismuth mainly occur in the crystal structures of rock-forming silicates and oxides of the common rocks in the Earths crust. These elements - with the exception of magnesium, iron, titanium, chromium, and zirconium - are trace elements in the minerals. They follow certain rules as reported by Goldschmidt (1954) in their ten-... 

The greatest decreases were found in iodine (down to 17%), iron (30%) and molybdenum (47%), whereas the zinc, copper, nickel, and manganese contents were lowered to half the amount found at the end of April. The age of the plants has a significant influence on the macro and trace element contents of these elements, which are essential for flora and fauna. Generally, herbivorous wild animals eat foods rich in macro and trace elements in early spring. 

The apparent absorption rate of the macro elements in humans with a mixed diet varied between 98% for sodium, 83% for potassium, 61% for phosphorus, 35% for magnesium, and 13% for calcium. Ovolacto-vegetarians have a significantly decreased apparent absorption rate for magnesium and calcium, and apparent absorption rates for trace elements varied between 81% for iodine, 62% for selenium, 42% for nickel, 37% for molybdenum, 2.5% for zinc, and 2.0% for manganese. 

This does not mean that all the analytical problems have been solved. Far from it. Evidence from various sources shows that the results of trace element analyses, as currently reported by typical laboratories around the world, may be subject to very large errors indeed. For example, the ratios of highest to lowest laboratory mean values for human blood plasma or serum reported by Versieck and Cornells (1980, see also Ver-sieck, 1985) are 392 (No. of lab. means = 17) for aluminium, 178 (7) for arsenic, 1321 (30) for chromium, 1352 (14) for cobalt 3.2 (36) for copper, 64 (19) for manganese, 7.6 (6) for mercury, 443 (10) for molybdenum, 138 (21) for nickel, 4.5 (19) for selenium, 3.4 (3) for tin, approx. 12.000 for vanadium, and 5.1 (36) for zinc. The authors conclude that many of the disparities between the values reported by different investigators are due to inadequate sampling and sample handling, or to defective analysis. 

Copper interacts with numerous compounds normally found in natural waters. The amounts of the various copper compounds and complexes present in solution depend on water pH, temperature, and alkalinity and on the concentrations of bicarbonate, sulfide, and organic ligands. In animals, copper interacts with essential trace elements such as iron, zinc, molybdenum, manganese, nickel, and selenium and also with nonessential elements including silver, cadmium, mercury, and lead interactions may be either beneficial or harmful to the organism. The patterns of copper accumulation, metabolism, and toxicity from these interactions frequently differ from those produced by copper alone. Acknowledgment of these interactions is essential for understanding copper toxicokinetics. 

Until 1950, 13 mineral elements were classified as essential these comprised the major elements (calcium, phosphorus, potassium, sodium, chlorine, sulphur, magnesium) and the micro or trace elements (iron, iodine, copper, manganese, zinc and cobalt). By 1970, molybdenum, selenium, chromium and fluorine had been added to the list subsequently, arsenic, boron, lead, lithium, nickel, silicon, tin, vanadium, rubidium and aluminium have also been included, the list varying slightly according to the different authorities. Plant and animal tissues contain a further 30 mineral elements, in small quantities, for which no essential function has been found. They may be acquired from the environment, but it has been suggested that as many as 40 or more elements may have metabolic roles in mammalian tissues. Fortunately, many of these trace elements, especially those of more recent discovery, are required in such minute quantities, or are so widely distributed in foods for animals, that deficiencies are likely to be extremely rare under normal practical conditions. 

At this time there is evidence that in addition to the eleven major elements, thirteen trace elements are nutritional requirements for mammals and/or birds. These are iron, copper, zinc, vanadium, chromium, nickel, manganese, molybdenum, cobalt, tin, selenium, silicon and iodine. Additional elements are almost certain to be added to this list of essential micronutrients within the next few years. Information on some of these trace elements is summarized in Table 1. Listed are zinc, copper, chromium, iron... 

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