Chemistry – Page 51 – David Bradley

Open access chemical interview

The latest issue of the Reactive Reports chemistry news site is now live. In it, I discuss various advances in the chemical sciences including weighty issue of trans fat that has butter lovers everywhere declaring, “I told you so!” Also in issue 56, I report on the basic approach to chemotherapy that side-steps the need for a magic bullet and find out how NASA has lit a fuse under the planetary carbon debate.

Our reactive profile this month is Will Griffiths. Griffiths a chemist by training like me opted out of the lab early in his career with the aim of applying his chemical knowledge and expertise through an altogether different medium. He is now investing his time and energy in developing the ChemRefer.com website, which offers chemists every quick and open access to the free full-text chemistry literature. You can use this search tool via the Chemspy Toolbox or download the Chemrefer toolbar.

Inorganic gas puzzle

A postgraduate student has posted a research problem on sci.chem.analytical, which Sciencebase’s chemically aware readers might be interested in puzzling over.

The student seems to have discovered a new inorganic gas.

Apparently, he heated a zeolite which consists Analcime, feldspar and silica to 500 Celsius. X-ray fluorescence shows the presence of Si Al K Ca Na S Ti and Fe. When the heated material is dissolved in HCl, a gas is evolved with the following properties (summarized by M Farooq on CHEMED-L):

(a) It smells like ammonia

(b) It gives a precipitate with calcium hydroxide which re-dissolves in HCl

(These properties would suggest carbon dioxide, but….)

(d) It can be collected over water and has an ammoniacal smell but is not as irritating as ammonia

(e) The gas does not react with silver chloride in solution (unlike ammonia) but can colorize silver nitrate solution (goes from colorless to weak yellow, similar to iron(III) ions in solution)

It might be a gaseous hydride and is almost certainly not an organic compound as all would be destroyed at 500 Celsius. Arsine impuritues are unlikely as the X-ray fluorescence did not reveal arsenic.

So, what is it?

Lead in China’s children

Researchers in Beijing have carried out a meta-analysis of AAS and ICP-MS results published during 1994-2004 to obtain a countrywide picture of how the level of lead in children’s blood is changing and how where they live effects their exposure to this toxic element.

Perhaps predictably, the team found that those children living in urban or industrial regions had much higher levels of lead than those living in rural areas. The figures they reviewed also contrast sharply with the children’s western counterparts who have much lower lead levels on average. The issue is a matter of significant public health importance for China, the researchers say.

Exposure to lead can affect the central nervous system and affect learning ability and growth. It is ubiquitous in the environment and can be absorbed in the human body by inhalation and ingestion from a variety of sources such as contaminated water, soil, food, lead-containing products such as paint and from vehicle exhausts in areas where tetra-ethyl lead is still used as engine an anti-knocking agent.

More…

Anaerobics class

A QSPR (quantitative structure-property relationship) study of the anaerobic biodegradation of chlorophenols could lead to an improvement in the disposal of these potentially carcinogenic industrial waste products.

Youzhi Dai, Dasen Yang, Fei Zhu, Lanyan Wu, Xiangzheng Yang, and Jianhua Li of the Department of Environmental Engineering, at Xiangtan University, People’s Republic of China have based their analysis on quantum chemical and physicochemical descriptors, using partial least squares analysis to obtain a good prediction of the QSPR for the disappearance rate constant (logK) of chlorophenols (CPs) in an anaerobic microbial culture.

More…

True blue electric blue

polymer-led-mullen Wide angle X-ray scattering, photoluminescence, polarizing optical microscopy, differential calorimetry, and dielectric spectroscopy have been used to study the optical properties of a range of blue-light emitting organic compounds. The mechanism of the self-assembly of these oligoindenofluorenes up to the polymer, their thermal properties, and associated molecular dynamics also reveal important clues about their behaviour and potential for applications in organic light-emitting diodes (OLEDS) and other devices.

More…

A peak you reach

Rather than relying on MRI and follow-up biopsy to provide information about a suspect abnormality in the breast, researchers at the Memorial Sloan-Kettering Cancer Center in New York have demonstrated in preliminary trials that NMR spectroscopy could be used to significantly reduce the number of biopsies required to detect the early stages of breast cancer. NMR can lock on to the choline peak associated with malignancy during the MRI scan.

Lia Bartella MD and her colleagues found that NMR could reduce the need for biopsy by 58%. They demonstrated that 23 of 40 suspicious lesions could have been spared biopsy, and none of the resultant cancers would have been missed, in a study group. “All cancers in this study were identified with MR spectroscopy,” explains Bartella, “There were no false-negative results. These results should encourage more women to take this potentially life-saving test.”

More…

Alchemical musings

In my guise as ChemWeb’s Alchemist this week I report on how there may be no need for a magic bullet in cancer chemotherapy and a basic (as opposed to acidic) approach could be all that is needed. Also spotted a smashing discovery that could explains glassy substances and precludes an ideal standard for physicists.

The Alchemists all sees the swirling clouds clearing as various holes in the ozone layer finally seem to be on the mend, and we learn of a co-polymer that not only fends off barnacles but can smell nice too.

Finally, spontaneous chiral resolution with achiral ligands.

Google Pharmacy Phake

You know how keen Google is to expand it’s breadth? Well, how about this, it seems it’s swapped the oo in it’s logo for some ooh-la-la, in the shape of two blue diamonds stamped Pfizer.

Before you rush to get stocked up on tamiflu and viagra, however, check out The Register article on Google Pharmacy which reveals it to be a front for a fake drugs seller. How do they know it’s a fake seller, well they claim to be able to provide generic versions of dozens of drugs that are not yet off-patent, that’s how.

The spam that arrived advertising Google Pharmacy stated: “We’ve just launched a pharmaceutical interfaces for Google, as well as several new features for the people buying pills and using pharmaceutical interfaces”. Poor grammar aside, you just can rest assured that it was definitely not the real thing right from the start. Or, could you?

According to an unrelated article on WebProNews, the sponsored Googlads that appear when you search for the likes of “Vicodin” or “Oxycontin” are not necessarily from fully legitimate companies either. Some of these sites, which appear above and to the side of search results in the popular search engine, are selling direct drugs that usually require a doctor’s prescription.

Carmen Catizone, executive director of the National Association of Boards of Pharmacy, is according to WebProNews, talking with Google about a third-party service that will help them differentiate between rogue and legitimate pharmacies.

It will be interesting to see whether that works out, or whether the pharma spammers and scammers will simply find a way around it.

Round solution to a salty problem

Have you ever been frustrated by salt in humid weather? The little cubic grains get all sticky and clump together and won’t leap on to your seaside fish and chips no matter how hard you shake the salt shaker. The simple solution is simply to not use salt, after all they repeatedly tell us too much salt is bad for us.

Indian chemists worried that was too simple a solution of have come up with a way to make round salt that could be a boon to consumers and industry. According to an ACS news release, round salt represents a dream come true for researchers who have strived for years to smooth the shape of common salt.

Table salt (sodium chloride) adopts a cubic close-packed crystal structure and so the crystals themselves normally exist as cubes. Pushpito Ghosh, P. Dastidar and colleagues at the Central Salt & Marine Chemicals Research Institute in Bhavnagarwere not happy with this and have devised a method for making large quantities of salt in an almost spherical, bead-like, form. They describe how in the July 5 issue of Crystal Growth & Design. They use glycine to modify the crystal growht process and effectively force the sodium chloride crystals to grow at different rates on different crystal faces, so they end up with a different symmetry.

In this novel round form, rhombic dodecahedral, to be strict, salt can flow much more freely, without caking, that claggy effect of humid summer weather, which is great news for fish and chip fans. A bigger market may be industries that store and use sodium chloride by the tonne to make everything from bulk chemicals to dyes, fertilizers, paper and pharmaceuticals. For these companies, non-caking salt would flow more freely on the production line.

Free flowing or not, it doesn’t round off the problem of whether or not salt is good or bad for you.

Chirality – panda thumb

The chirality of life, an issue I’ve discussed on numerous occasions in these and other pages, emerges as yet another source of pseudo-science for the intelligent design lobby. Apparently, the bias in handedness among the molecules of life – amino acids, DNA, etc, could not have arisen spontaneously without a guiding hand…

An interesting discussion on this very subject is underway at The Panda’s Thumb blog, it will be interesting to see where it leads. However, my own interviews with chemists on this subject over the years point to a wide range of natural phenomena that could have led to the emergence of the chiral bias with no need to invoke a supernatural hand.