Graphene has been receiving a large amount of interest as its commercial possibilities begin to be realised. Now, with hundreds of companies offering commercial graphene production, analytical measures of graphene quality are required. Raman spectroscopy can be used to “understand the number of layers, strain, doping and importantly the level of disorder present in graphene”, which is described in this article: “Graphene characterisation and standardisation via Raman spectroscopy” by Andrew Pollard and Debdulal Roy.
Fine sediments, often due to run-off from the land, can clog the surface and sub-surface spaces in gravel beds used by spawning fish to lay their eggs and by aquatic insects. Without an adequate flow of oxygenated water, the eggs and insects die. Heather Haynes, Susithra Lakshmanan, Anne-Marie Ockelford, Elisa Vignaga and William Holmes tells us about this in “The emerging use of magnetic resonance imaging to study river bed dynamics”. They have studied the infiltration of various sediments into model gravel beds both outside and flowing through a MRI instrument! They conclude that MRI “provides an exciting opportunity to unravel a plethora of processes relevant to wider environmental science”.
Jürgen Gross has been using ambient mass spectrometry to look at the presence of polydimethylsiloxanes (PDMS) in food prepared in silicone rubber objects and on baking parchment. He shows that PDMS migrates into the food, something perhaps we should think about if in the mood for some baking!
Stanislav Strekopytov tells us about “The use of inductively coupled plasma mass spectrometry to quantify chemical hazards in natural history collections: arsenic and mercury in taxidermy bird specimens”. It is quite shocking to learn about the use of poisons to preserve taxidermy specimens in the past. Nowadays it is essential that the dangers from such specimens are known before they can be handled by museum staff and particularly if they might be touched by visitors. ICP-MS analysis provides fully quantitative information on bulk contents of toxic elements in taxidermy specimens and so is well suited to this task.
Mark Tobin and colleagues describe “Fourier transform infrared spectroscopy and imaging of dragonfly, damselfly and cicada wing membranes”. Insects and plants have evolved highly specialised surfaces such as being highly water repellent or superhydrophobic, which also confers self cleaning properties. This is of interest to materials scientists to help in the development of manufactured materials with similar properties. High spatial resolution FT-IR spectroscopy and imaging provide useful information about the complex chemical patterning that contributes to this functionality.
The “Application of Raman and photoluminescence spectroscopy for identification of uranium minerals in the environment” is described by Eric Faulques, Florian Massuyeau, Nataliya Kalashnyk and Dale Perry. Uranium forms a large number of compounds and complexes, and these are most helpful in the study of uranium, its chemistry and transport in the environment. Raman and photoluminescence spectroscopy provide complementary information and are powerful tools for direct speciation of uranium and identification of natural uranyl minerals relevant to the environment.
Yvonne Fors, Håkan Grudd, Anders Rindby and Lennart Bornmalm tell us about “X-ray fluorescence for cultural heritage: scanning biochemical fingerprints in archaeological shipwrecks”. Two outstanding examples of the preservation of wood are the warships Vasa, in Stockholm and the Mary Rose in Portsmouth and this article looks at the role XRF has played in the preservation of the wood of both ships.
“From lake ecology to biofuels—applications of Fourier transform infrared spectroscopy to algal research” is the topic of Andrew Dean, Jon Pittman and David Sigee. Algae are essential for our continued live on Earth, and FT-IR spectroscopy can increase our understanding of their physiology and biotech potential.
Even though lead in fuel has been banned for a number of years, it is still present in by the roadside, as are many other pollutants from vehicles. The combination of Raman spectroscopy and µ-ED-XRF is of particular value. The advantage Raman has is in the possibility of focusing on individual grains, thereby obtaining the spectrum of each grain that comes from traffic-emitted particles.
It is possible to obtain both infrared spectra and thermal analysis data of individual layers in a cross-sectioned multilayer film. Since both techniques are AFM-based, the topographical features can be readily linked to the spectroscopic and thermal data at a much higher spatial resolution than previously achievable.