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Minerals in Detail
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
MOLYBDENUM
Molybdenum - chemical details
| Symbol | Mo |
| Atomic number | 42 |
| Atomic mass | 95.94 g.mol-1 |
| Electronegativity | 1.8 (according to Pauling) |
| Density | 10.2 g.cm-3 at 20°C |
| Melting point | 2610 °C |
| Boiling point | 4825 °C |
| Vanderwaals radius | 0.139 nm |
| Ionic radius | 0.068 nm (+4) |
| 0.06 nm (+6) |
| Isotopes | 11 |
| Electronic configuration | [ Kr ] 4d5 5s1 |
| Energy of first ionisation | 651 kJ.mol-1 |
| Standard potential | - 0.2 V |
| Discovered | 1778 - Carl Wilhelm Scheele |
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Molybdenum - Description
Molybdenum is a silvery white, very hard transition metal, though somewhat softer and more ductile than tungsten. It was often confused with graphite and
lead ore. It has a high elastic modulus, and one of the highest melting points of all pure elements. Molybdenum is fairly resistant to acids, being
"attacked" only slowly.
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Molybdenum - Industrial applications
Molybdenum is used as a "hardener" in steel manufacture, in lubricants, circuit boards, microwave devices and heat sinks. For details on
industrial applications and impact on the environment see www.lenntech.com/Periodic-chart-elements/Mo-en.htm
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Molybdenum - In natural form
Molybdenum differs from the other micronutrients in soils in that it is less soluble in acid soils and more soluble in alkaline soils, the result being that
its availability to plants is sensitive to pH and drainage conditions. Some plants can have up to 500 ppm of the metal when they grow in alkaline soils.
Molybdenum is found mainly as Molybdenite ore (MoS2). Some molybdenite is obtained as a by-product of tungsen and copper production. The main mining areas are the
USA, Chile, Canada and Russia, with world production being around 90.000 tonnes per year, and reserves amounting to 12 million tonnes.
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Molybdenum - Impact on health
The oxidation of xanthine to uric acid, a process of purine catabolism, is catalyzed by xanthine oxidase, a molybdenum-containing enzyme. The activity of
xanthine oxidase is directly proportional to the amount of molybdenum in the body. However, an extremely high concentration of molybdenum reverses the trend,
and can act as an inhibitor in both purine catabolism and other processes. Molybdenum concentrations also affect protein synthesis, metabolism, and growth.1
Molybdenum is present in approximately 20 enzymes in animals, including aldehyde oxidase, sulfite oxidase, xanthine oxidase.2, 3
These enzymes in plants and animals catalyse the reaction of oxygen in small molecules, as part of the regulation of nitrogen-, sulfur- and carbon cycles.
Molybdenum acts as a detoxification agent in the liver as a part of the sulfite oxidase enzyme, which destroys sulfite, a common preservative in foods and
drugs.
In a 70 kg human body, there is approximately 9.3 mg molybdenum, comprising .00001% of the total body mass.4 It
occurs in higher concentrations in the liver and kidneys, and in lower concentrations in the vertebrae.5 Molybdenum is also
present within human tooth enamel and may help prevent its decay.6
Pork, lamb, and beef liver each have approximately 1.5 parts molybdenum per million. Other significant dietary sources include green beans, eggs, sunflower
seeds, wheat flour, lentils, and cereal grain.2
Chemical Details | Description | Industrial Applications |
In Nature | Health Impacts | Daily Intake
Molybdenum - Recommended daily & maximum intake
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Risk free |
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intake? |
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Food sources? |
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Result of overdose? |
| Age Group |
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RDA |
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Limit |
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Infants
0-6 mo
7-12 mo
Children
1-3 y
4-8 y
Males
9-13 y
14-18 y
19-30 y
31-50 y
50-70 y
> 70 y
Females
9-13 y
14-18 y
19-30 y
31-50 y
50-70 y
> 70 y
Pregnancy
< 19 y
19-30 y
31+ y
Lactation
< 19 y
19-30 y
31+ y |
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(ug/d)
2.0
3.0
17.0
22.0
34.0
43.0
45.0
45.0
45.0
45.0
34.0
43.0
45.0
45.0
45.0
45.0
50.0
50.0
50.0
50.0
50.0
50.0 |
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(ug/d)
ND
ND
300.0
600.0
1,100.0
1,700.0
2,000.0
2,000.0
2,000.0
2,000.0
1,100.0
1,700.0
2,000.0
2,000.0
2,000.0
2,000.0
1,700.0
2,000.0
2,000.0
1,700.0
2,000.0
2,000.0 |
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Legumes
Grain products
Nuts |
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Reproductive effects found in animal studies |
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Explanations:
ND = Not determinable. There is either insufficient data on adverse effects and/or concern with the body's ability to handle excess amounts. In most
instances it is wise not to supplement for this particular element, but to rely on diet to provide sufficient quantities.
RDA = Recommended Dietary Allowance. May be used as a goal for daily intake. RDAs are set at a level that should meet the needs of 97-98% of all individuals.7, 8, 9, 10
Limit = The maximum level of daily nutrient intake from all sources that is highly likely to pose no risk of adverse effects.7, 8, 9, 10
References:
- Mitchell, P. (2003). Overview of Environment Database. International Molybdenum Association. http://www.imoa.info/HSE/environmental _data/human_health/molybdenum_levels_humans.html Retrieved on 23 Sep 2008.
- Emsley, J. (2001). Nature's Building Blocks. Oxford: Oxford University Press, 262-266.
- Nielsen, F. (1993). Ultratrace Elements of Possible Importance for Human Health: An Update Essential and Toxic Tace Elements in Human Health: An Update, pages 355-376, 1993.
- Lide, D., ed. (2006). CRC Handbook of Chemistry and Physics, 7, Chemical Rubber Publishing Company, p. 18.
- Considine, G., ed. (2005). "Molybdenum", Van Nostrand's Encyclopedia of Chemistry, New York: Wylie-Interscience, pp. 1038–1040.
- Ismail, M. Dental Problems and Diet. Health and Nutrition. Bawarchi. http://www.bawarchi.com/health/dental.html Retrieved on 23 Sep 2008.
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (1997). Dietary Reference Intakes for Calcium, Phosphorous, Magnesium, Vitamin D, and Fluoride. Food and Nutrition Board: Institute of Medicine.
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (1998). Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6,
Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Food and Nutrition Board: Institute of Medicine.
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (2000). Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Food and Nutrition Board: Institute of Medicine.
- Standing Committee on the Scientific Evaluation of Dietary Reference Intakes (2001). Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Food and Nutrition Board: Institute of Medicine.
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