Specific method to detect dangerous levels of fluoride (science daily)

PharmaLive.com (9 December 2010) - used in appropriate amounts, it can do more teeth and help in the treatment of osteoporosis. When excessive quantities are consumed, however, it can be a killer - carcinogen that causes bone, lung and bladder cancer. "it" is a common additive fluoride in the water drinking most communities and an ingredient in the vast majority of adult toothpastes commercially produced.

Determine the level of fluoride either water-soluble product consumption or the human body is an important and attractive for scientists challenge. For that, a researcher at the University of State of Florida has developed a molecular sensor that changes colour when a sample containing fluorine is added.

"The U.S. Environmental Protection Agency advises that 1 part per million (ppm) of fluoride ions is acceptable in drinking water, but more than 2 ppm is regarded as serious risk to health," said Sourav Saha, an Assistant Professor in the former USSR of the Department of chemistry and Biochemistry and integrative Institute of nanoscience. "" "" Because fluoride is carcinogenic even in small doses, a sensor is necessary to detect fluoride selectively at very low concentrations and in the presence of other naturally and biologically important ions. »

In collaboration with a team of students and fellows, Saha was able to develop such a sensor. His team of researchers has discovered that a compound called diimide (NDI) naphthalene interacts with uniquely colourful fluoride ions.

"NDI is a family of neutral (although electron deficient) aromatic compounds are colorless, that fluoride is added", said Saha. "A small amount of fluoride will quickly turn orange sample, while much more transform pink." In this way, it becomes very easy to determine the presence of fluoride in the water, but at what level. »

Although there are other sensors of fluoride, many many of them cannot distinguish between fluoride and other anions - negatively charged ions - that might be present in the water.

"Despite the fact that they can detect fluoride, they could not accurately measure the levels of fluoride," said Saha. "Naked eye detection of fluoride concentrations is an advantage of NDI based sensors. Our sensor relies on an electronic receiver NDI fluoride ion transfer in this case to change color or visible response event to generate a signal, that is. Electron transfer process can be reversed, and the sensor can be reclaimed and reused over and over again.

Designing an appropriate sensor laboratory Saha reached a remarkable "nanomolar" fluoride, sensitivity which means that it can detect approximately ten thousandth of one milligram of fluoride in a litre of water. This makes it one of the most sensitive sensors fluoride known to date.

Water fluoridation has been widely used in the United States since about 1960. Although often a subject of controversy, Saha says that he had to improve the overall dental health through a very basic chemical process. When added to water systems, fluoride reacts with a natural mineral calcium phosphate and product called fluorapatite compound. Fluorapatite then bindings with teeth in humans to form a hard layer services offshore corrosion protection. This is important for dental health.

However, an excessive amount of fluoride in water can cause a condition known as dental fluorosis, especially among young children. It follows an aspect marble of the tooth enamel as well as possible cracking and between teeth.

Fluoride is also used in several medications to treat osteoporosis brittle bone disease. Given appropriate amounts, fluoride appears to stimulate the formation of new bone tissue. However, when an excessive amount of fluoride accumulates in the tissues of the body, they can lead to a variety of diseases, health including skeletal fluorosis, causing pain and damage to bones and joints. Excessive fluoride over a length of time also was linked to development of osteosarcoma - malignant and potentially fatal - bone cancer and cancers of the lung and bladder. For these reasons and others, fluoride has not been formally approved by the Food and Drug Administration for the treatment of osteoporosis in the United States.

Artificial fluoridation of drinking water is commonly practiced in many industrialized countries. While the precise number is not available, possibly 400 million people living outside the United States are located in areas where water is fluoridated artificially, according to the British society of Fluoridation. Untold millions of others, especially in the regions of Africa, the India and China, based on water sources whose natural fluoride level exceeds EPA recommendations. Efforts to measure the amount of fluoride present in many of these areas are unclear and inconsistent.

"This is an issue very important for public health in the world," said Saha. "Some countries developing fluoridated water but are not a way to accurately measure." Others are drinking water was treated with fluoride, but which may contain dangerous amounts already naturally. Clearly there is a critical need for a sensor fluoride which can tell whether their water supply is safe. »

A document describing the results of his team was recently published by the journal of the American Chemical Society. He has written collaboratively by Saha and his postdoctoral researcher, Samit Guha. It was also stressed in the December 6, 2010, from chemical issue and new techniques.

In addition, Saha filed a US patent on his process of detection of fluoride in June 2010. It asks whether, in the following year, if the patent will be granted. If so, the next likely step would be to license his discovery to an external firm that could test it for the commercial potential and then, if all goes well, develop a marketable product.

"It's a clever idea," said John Fraser, assistant vice President the State of Florida research and Director of the Office of development of intellectual property and marketing and economic development. "Using a test simple color to determine safe fluoride levels will lead to a tangible benefit to society." Once commercialized, people benefit the United States, but in countries with high natural content but dangerous fluoride also. »

Warning: this article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those PharmaLive.com or its staff.

Source of the story:

The story above is reproduced (with drafting adaptations by staff at PharmaLive.com) materials provided by Florida State University.

Reference of the review:

SAMIT Guha, Sourav Saha. Remote sensing by an Interaction Anion-p fluoride ion. Journal of the American Chemical Society, 2010; : 101130112154057 DOI: 10.1021/ja107382x

Note: If no author is given, the source is cited for this.