ChemWeb Newsletter

Not a subscriber? Join now.January 26, 2012

special message from ChemWeb

At the ACS Fall Meeting in Denver.,CO, ChemWeb sponsored an iPad 2 raffle to promote new subscribers. We are happy to announce that Melissa McAlexander, an Assistant Professor in the Department of Natural Sciences at Notre Dame de Namur University in Belmont, California, is one of many new Alchemist subscribers, and our iPad 2 winner. Melissa teaches a wide range of courses including General Chemistry, Contemporary Environmental Issues, Microbiology Laboratory, and Immunology.


The Alchemist learns how to manipulate tiny polystyrene beads with a set of micro-tweezers this week and spots the smoking gun in forensics using capillary-scale ion chromatography and suppressed conductivity. In the world of chemophobia has asked why parabens are still the focus of research into underarm hygiene and breast cancer despite the lack of evidence linking the two in any way. There is also an elemental discovery this week concerning that lowliest of metals, zinc, which may have activity in reducing the symptoms of the common cold. A venture that sounds truly alchemical sees research into burning ice heating up. Finally, a prize teacher.

A set of micro-tweezers developed by scientists at Purdue University in West Lafayette, Indiana, could be used to build components for microelectromechanical systems (MEMS). Team leader Cagri Savran explains that the tweezers can be used to manipulate tiny polystyrene spheres and assemble them into three-dimensional structures. The device, which requires no electricity supply, comprises a "thimble" knob from a standard micrometer, a two-pronged tweezer made from silicon, and a "graphite interface," which converts the turning motion of the thimble knob into a pulling-and-pushing action to open and close the tweezer prongs. The same tweezers might also be used to handle spheres of stem cells or other biological entities and place them on to analytical devices or sensors.

Researchers in the UK have turned to capillary-scale ion chromatography and suppressed conductivity detection to develop a new method for the forensic analysis of gunshot residues, sweat and latent fingerprints. The application of statistical techniques allowed them to extract data to reveal whether fingerprints were left by someone who had recently discharged a firearm and even whether or not the suspect is a smoker. The scale of the technology required would enable portable forensic testing as well as being amenable to situations in which analysis of metallic content is not possible.

Tabloid scare stories and sensationalist emails concerning a wholly unproven link between parabens in underarm hygiene products and female breast cancer were bolstered again this month. A small study showed that of samples from 40 breast cancer patients all contained small quantities of these organic preservatives. The study did not analyse samples from non-patients as controls. Moreover, given that some of the women had never used underarm products yet still showed parabens in their samples suggests not that breast cancer is linked to these products but that they are simply ubiquitous. Epidemiological studies dating back to the early 2000s have shown no link and other studies have demonstrated that parabens are almost always present in urine samples tested.

Zinc has been The Alchemist's element of choice for warding off an imminent dose of the common cold, but is there any truth in the received wisdom that boosting intake of this trace element can stifle the worst symptoms of rhinovirus infection? It is unlikely that otherwise healthy individuals with a balanced diet who take regular exercise will be deficient in zinc. However, a Cochrane review of 15 randomized clinical trials suggests that taking zinc within 24 hours of the onset of symptoms can ameliorate the worst excesses of the body's response to a common cold and reduce the the number of days of misery.

A team at Pacific Northwest National Laboratory, PNNL, has carried out a computer analysis of gas hydrates to try and understand key details about their structure. The study is the first to accurately quantify the molecular-scale interactions between hydrogen or methane, the "natural" gas in the hydrates and the water molecules that form hydrogen-bonded molecular cages around them. The PNNL team demonstrated that hydrates can hold hydrogen at an optimal capacity of 5 mass percentage, which is considered a viable figure by the US Department of Energy making gas hydrates a practical and affordable alternative fuel source.

Organic chemist Brian Coppola of the University of Michigan is the recipient of the biannual Robert Foster Cherry Award for Great Teaching, which is given by Baylor University in Texas, in recognition of outstanding classroom teaching. The awards were established in 1991 to stimulate discussion in the academy about the value of teaching, and to encourage departments and institutions to value their own great teachers. It is named for 1929 Baylor graduate Robert Foster Cherry. Coppola receives $250,000 and his department $25,000. The U-M highlights its recent released payroll report, which cited Coppola's salary as $139,550 in 2011.

Not a subscriber? Join now.January 13, 2012


In the first issue of the putatively but unlikely apocalyptic year of 2012, The Alchemist sniffs out some unsavory effluent from the local "greasy spoon," wonders what are the pitfalls of doing science at Pitt and chases Olympic dreams with a hydrogen relay race. There is serious pollution control heading for the farm, we hear, and there really is no end to silicon in sight. Finally, alternative chemistry awards may be facetious in flavor but have a serious message.

A new cheminformatics approach to analyzing effluent waste water from restaurants and the food industry that can cope with the oil and grease in a sample has been developed by researchers in China. The team uses statistical methods to combine data from UV-Vis spectra, turbidity and other measurements to obtain important indicators of water quality in a fusion approach to analysis. The method could be used to develop online, real-time monitoring of effluent from the food industry and outlets.

One of the most porous materials ever made has been created by a team at the University of Pittsburgh. Nathaniel Rosi and colleagues have used the old "Tinker Toy" analogy to explain their new metal-organic frameworks, which could find applications in pharmaceutical delivery and high-density fuel gas storage. The team's materials follow the usual pattern and comprise metal-carboxylate cluster vertices and long, branched organic linkers, but it is their view on the vertices rather than the linkers that makes them special. They have worked with large metal-biomolecule clusters, such as zinc-adeninate building blocks, to construct "bio-MOF-100", which is a mesoporous MOF with the largest reported pore volume - of 4.3 cubic centimeters per gram.

A relay race of hydrogen atoms has been followed by Thomas Frederiksen, who is currently working in the Donostia International Physics Center (DIPC), Spain and colleagues in Japan, using scanning tunneling microscopy. The relay race takes place in well-defined chains on a metal surface. By sending a pulse of electrons through a water molecule at one end of the chain, hydrogen atoms propagate one by one along the chain like dominoes in motion, the team explains. The result is the transfer of a hydrogen atom, like the baton in a relay, from one end of the chain to the end. This way of manipulating matter could open up new ways to exchange information between novel molecular devices in future electronics.

A proof-of-concept unit that incorporates a biofilter and a heat exchanger can reduce ammonia emissions from livestock barns, specifically those housing swine or chickens, and at the same time warm the fresh air that is pumped into the barns. The unit has been developed through a collaboration between researchers at North Carolina State University and West Virginia University with the aim of reducing air pollution from these parts of the food industry. “The technology is best suited for use when an operation wants to vent a facility that has high ammonia concentrations, and pump in cleaner air in preparation for a fresh batch of chicks or piglets - particularly in cold weather. It is also suitable for use when supplemental heat is required for raising the young animals,” explains lead author Sanjay Shah from NSCU.