Chemistry – Page 45 – David Bradley

Giant planet makes metallic water

Can planetary giants make metallic water? That’s a question answered theoretically by US scientists in this week’s Alchemist, we also learn why mussels are not as happy as clams thanks to Prozac, what makes organic semiconductors light up and the possibility of powering your mp3 player with your beach umbrella. Also in this week’s news distillate, uranium-munching bacteria have the mettle to construct nanoscopic platinum particles. Finally, digestion on a grand scale could be releasing five times as much methane into the atmosphere above Siberian lakes.

The latest chemistry news from ChemWeb.

Extra virgin solvents

Olive Oil Extracting oil from olives requires solvents and residues of halogenated solvent can sometimes leave a toxic taint in the product. European Union rules restricted the acceptable levels of these residues for the sake of public health but new sensitive and precise analytical procedures are needed to allow strict quality control and regulatory testing to be carried out.

Now, Spanish researchers have turned to chemical informatics to help them optimise the extraction-analysis process. Bromoform, chloroform, ethylene dichloride, trichloroethene, tetrachloroethene, dibromochloromethane, and bromodichloromethane are all employed to extract crude olive-pomace oils from the solid residue obtained in the pressing of olive oils. The EU limits the residues of these solvents to 0.1 milligram per kilogram for individual compounds and double than that for total content. “These solvents have a great negative influence on both the quality of oils and human health,” JosÃ© Luis GÃ³mez-Ariza of Huelva University told SpectroscopyNOW, “They are all considered to be possible carcinogens and, therefore, human exposure to such compounds should be minimized.”

Making light of spectroscopy

A radically different approach to detecting the way atoms resonate in a magnetic field could improve the sensitivity of NMR spectroscopy, according to US scientists.

Conventional liquid and solid relies on detecting the net dipolar magnetic field outside a spin-polarised sample, explain Michael Romalis and colleagues at Princeton University, New Jersey. However, this only offers the NMR spectroscopist limited structural and spatial information. As such NMR has been extended with elaborate techniques involving magnetic field gradients and spin correlations. Using a laser beam, which is by definition a polarised light source has provided a new avenue of research – optical NMR. However, until now, this has been limited to quantum dots and other specialists materials. Romalis and his colleagues hoped to extend optical NMR to a much wider field of research.

Find out more in the latest news round-up on spectroscopynow.com

Spanish heavy metal

Spanish scientists have used some tricky mathematics to help them work out where heavy metal comes from. Their findings, based on atomic analysis, will provide information useful in protecting us from these toxic elements.

Contamination of soils with heavy metal contaminants has become and increasingly important environmental issue, particularly in developed countries because of shifting land-use patterns. Such contaminants readily leach into water systems or are assimilated by certain crops with putatively detrimental effects on wildlife, livestock and human health. Understanding the role of soil type, organic content, clays and salts, such as carbonates, is essential to characterising the risks and developing a soil protection policy. Indeed, the European Thematic Strategy for Soil Protection requires the characterization of the content and source of heavy metals in soils so that quality standards can be established.

Read on…

Logical chemistry

It has been thirteen years since Prasanna “AP” de Silva and his colleagues at Queen’s University Belfast published their first paper in the international science journal Nature, outlining how they hoped to convert small molecules into the kind of logical units that could carry out computations. In the September issue of Reactive Reports, we explain how this work has now led to the first practical application of logical chemistry and provided combinatorial chemists with a way to add a unique tag to potentially millions of molecules in parallel.

Combichem uses a set of chemical building blocks to synthesize a vast library of new molecules by building them up in all possible combinations of the building blocks. But, tagging each molecule has always been a stalling point. De Silva’s work could release the bottleneck. Read all about logical molecular tags in the new issue of RR.

Also, in this month’s issue, Peter Loew is featured . Peter is managing director of chemoinformatics software company InfoChem. There have been a lot of changes in the IT world since InfoChem was formed in 1989 and Loew revealed how these changes have evolved the company: Read the full interview.

Metabolic Typing Body Chemistry and Diet

Of all the millions, if not billions, of web searches being carried out across the net every day, there are approximately 54 looking for this quite spectacular string of words: the metabolic typing diet customize your diet to your own unique body chemistry

It was the word chemistry, that brought it to near the top of a recent keywords trawl I was carrying out to help find new topics to offer visitors to the Chemspy site.

Turns out to be a book. I should’ve guessed, why else would so many people search on such a specific string of words. You can buy it here.

The book’s blurb explains the gist of author, William Linz Wolcott’s diet theory: “People are unique in more ways than we can see. Stomachs and other internal organs come in many different shapes and sizes. Digestive juices, too, can vary dramatically from one person to another…it stands to reason that different foods have very different effects on different people.”

Wolcott believes that tailoring your diet to your body’s particular chemistry – metabolic typing – will improve digestion, circulation, immunity, energy, and mood. To determine your type, he has you take a 65-question test (the questions range from nose moisture to how you feel about potatoes), then place yourself in one of three categories: protein type, carbo type, or mixed type.

Sounds like this will have great potential for those who really cannot bring themselves to let go of the remote control, get up off the sofa and do some exercise. Once they realise it doesn’t actually work for them (usually takes about two weeks for that to happen), this tome will be find its slot on the book shelf alongside Atkins, Cabbage, and F…

Bacteria build nano catalysts

Bacteria could be the key to improving metal catalysts for the chemical industry, according to research in Germany. Scientists from the Forschungszentrum Rossendorf in Dresden have exploited the survival skills of bacteria that live in uranium mining waste to make tiny clusters of the precious metal palladium. These tiny bullets, just a few billionths of a millimetre across, are much better catalysts than normal palladium, which is used in speeding up chemical reactions and in the catalytic converters of cars.

The bacterium, Bacillus sphaericus JG-A12 has a protective protein layer that allows it to survive in the extreme environment of a uranium mining waste pile. This protein layer comprises a grid of nanoscopic pockets of identical size that can trap toxic metal ions and prevent them from harming the bacterium by converting them into tiny clumps of insoluble metal.

Full story…

Scanning vegetative patients

Last week, Cambridge and Belgian researchers reported that they could observe almost identical brain activity in healthy volunteers as a patient purportedly in the persistent vegetative state following emergence from a coma (the patient was originally in a car crash in July 2005). The implications of this functional MRI work are that some (but by no means all) PVS patients may have consciousness to some degree despite their outwardly appearing inanimate.

It is incredibly tragic to imagine that there might be PVS patients who do have some consciousness but cannot move or communicate with the outside world. Functional MRI may in the long-term lead to a way to communicate with such patients.

That said, there is a long way to go before fMRI or any other technique can provide us with a full understanding of the persistent vegetative state and some researchers are cautious of extrapolating the Cambridge findings too far. Indeed, if you read my report about the research in the latest issue of SpectroscopyNOW.com, you can see quite clearly that the fMRI scan of the control volunteer and the patient are superficially similar – activity is in the same region, after all – but the level of activity appears to be markedly less prominent in the patient. This could have important implications for what is meant by such a patient having consciousness as we know it.

Much more research is now needed to help us redefine the PVS. This is perhaps a matter of some urgency given the current definition of PVS states that these patients cannot experience pain and suffering as these are attributes of consciousness.

Chemistry Central Journal launched

A new open access outlet for chemists’ peer reviewed research was launched today. Chemistry Central Journal. Publisher BMC says, the journal is the first international open access journal covering all of chemistry and will publish its first issue early in 2007.

Bryan Vickery, speaking today at the journal’s launch being held during the ACS meeting, said, ‘I am delighted by the number of noted chemists and scientists who have agreed to join the Editorial Advisory Board of the journal from the outset.” Among them is 1996 Nobel laureate Robert Curl. “I think open access journals are a great idea and am delighted to join this venture as a member of the Editorial Advisory Board,” he said.

Vickery continues, “Open communication of research results in physics and biomedicine has evolved rapidly over the last few years. Many believe Chemistry has lagged behind, with access to chemistry-related journals and databases still predominantly limited to subscribers only.”

Vickery explains that Chemistry Central Journal will offer a home for research in areas where there has previously been no open access journal available. “Chemistry Central Journal aims to change all that, by offering an open access publishing option to scientists worldwide,” Vickery says, “The journal will cover all areas of chemistry, and will be broken down into sections.”

Sex and phthalates

pvc dildos and phthalates It seems even the sex industry is not immune to chemophobia, according to a recent Greenpeace Netherlands announcement, users of PVC sex toys destined for orificial use should not. Use them, that is.

According to Greenpeace, these plastic devices can contain “extremely high concentrations of phthalate plasticisers which allegedly pose a risk to human health and the environment”. The organisation wants the European Union to ban the use of phthalates in sex toys as it already has done with phthalates previously used in the manufacturer of PVC childrens’ toys.

The Daily Telegraph reports how, “The environmental group said it was shocked to find that seven of the eight sex toys it had tested contained between 24 and 51 per cent of phthalates.”

Their actual report shows that individual phthalates in a range of products are at at trace amounts. They do report the presence of 490 g per kilo of di-isodecyl phthalate (DIDP) in one device as determined by GC/MS.

There is so much disinformation about phthalates on the web, that it is almost impossible to track down the actual levels of additives used as primary plasticisers in PVC products. I’d assume the percentage needs to be relatively high to make the devices we’re currently discussing “plastic” enough, but 51% seems very high regardless.

Moreover, where are the tests revealing how much of this “shocking” percentage might actually leach out of such a device during normal usage? And, even if there is a degree of leaching, does that correlate with actual risk to health. These questions are yet to be answered for any devices whether sex toys, children’s toys or medical devices.

Any thoughts?