As you will have noticed from this issue’s cover, we are making a colourful start to 2016. In the first article on “The analytical niche for Raman spectroscopy in biological pigment research”, Daniel Thomas and Cushla McGoverin suggest that Raman spectroscopy may have a particularly valuable role in pigment biology research. Pigments are almost universal in biology and are the basis of much of what we find attractive in flowers, birds and sea life, such as the fan corals on the cover. The authors show how Raman spectroscopy can be used to quickly confirm the presence of a pigment as well as providing more detailed knowledge about unknown pigments.
Another surface problem is tackled by Richard Pilkington, Stuart Astin and John Cowpe: “Application of laser-induced breakdown spectroscopy for surface hardness measurements”. Measuring the hardness of materials is not entirely straightforward, and the authors show that laser-induced breakdown spectroscopy offers the potential for in situ hardness measurements, without prior sample preparation.
This article tells us about another: “Fast and versatile ambient surface analysis by plasma-assisted desorption/ionisation mass spectrometry”. They show that surface analysis can greatly benefit from approaches using surface–plasma interactions and that PADI shows significant promise to become a valuable and versatile tool for this.
To ensure that the removal and treatment of our sewerage meets increasingly high standards, it is important to be able to monitor the water online both to provide timely information and also to establish changing patterns over days, weeks and seasons. In their article “On-line monitoring for improved wastewater system management: applications of ultraviolet/visible spectroscopy”, Rita Brito, Rita Ribeiro, Tatiana Arriaga, Catarina Leitão, Nìdia Lourenço, Filipa Ferreira and Helena Pinheiro demonstrate the value of on-line UV/vis spectroscopy for wastewater quality monitoring in decentralised wastewater treatment and for spectral on-line monitoring of key quality parameters at the inlet to wastewater treatment plants.
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 authors describe “Infrared mapping spectroscopic ellipsometry”. Recent developments in fundamental and materials research have increased the value of mapping techniques such as ellipsometry. IR ellipsometry, since it operates in the mid-IR fingerprint region, provides complementary information on composition, structural properties and interactions
In situ spectroscopic methods such as infrared, Raman and UV/vis spectroscopy are powerful tools to gain insight into reaction mechanisms and catalyst actions in homogeneously catalysed reactions. These methods and combinations of them offer great potential for the real-time monitoring of reactions in the liquid phase, for mechanistic studies as well as process control and kinetics.
Research is under way as to the possibility of using high-precision isotopic analysis of metals in a biomedical context. The goal is to develop methods for medical diagnosis on the basis of isotopic analysis of mineral elements in biofluids, for diseases that can otherwise only be established at a later stage or via a more invasive method (e.g., a biopsy) and/or for prognosis purposes. Whilst this work is in a very early stage, it is known that various diseases have an influence on the uptake, metabolism and/or excretion of essential mineral elements and thus, can cause a difference in their isotopic composition in biofluids.
“In vivo Raman spectroscopy of skin” is Paul Pudney’s topic. The skin is a most important part of our bodies. There is great interest in studying it to help understand the many skin diseases we are prone to, including cancer, to develop skin care products and, increasingly, as an alternative route to administer pharmaceuticals instead of through the gut. Raman spectroscopy is an excellent tool to study these, and has particular advantages in its ability to do so in vivo.
Christian Schröder tells us about “Mössbauer spectroscopy in astrobiology”. Iron is abundant in the Earth’s crust, as well as on Mars and is likely to be so also on Jupiter’s moon, Europa. Iron is important for life and may have played a role in the origin of life as an energy source and by providing mineral surfaces as a template for surface metabolism. Iron continues to be essential for almost all organisms as the functional centre of many proteins and enzymes. Mössbauer spectroscopy is a powerful tool to study iron-bearing solid substances and as such has applications in the search for life in other parts of our Solar System.
Sampling on important works of art is not possible and this is the main reason why only non-invasive techniques, such as MSI, are becoming increasingly popular to assist with undertaking conservation decisions.
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.
“Optical spectroscopy in therapy response monitoring: an awakening giant” by Arja Kullaa, Surya Singh, Jopi Mikkonen and Arto Koistinen looks at the important advances made by optical spectroscopy techniques, such as diffuse optical spectroscopic imaging (DOSI), Raman, diffuse reflectance and fluorescence spectroscopy, in changing how cancer is managed in patients. The ability to repeatedly monitor tumour dynamics to see how effective a particular treatment has been has enormous potential for us all.
The authors tell us about “Two dimensional elemental mapping by laser-induced breakdown spectroscopy”. LIBS seems to be finding increasing applications and to be receiving interest by the instrument manufacturers at present. The article provides an introduction to the technique and goes on to show how it can be used for elemental mapping in materials analysis.
“Rheo-nuclear magnetic resonance spectroscopy: a versatile toolbox to investigate rheological phenomena in complex fluids” is Claudia Schmidt’s topic. Rheology is an important science, and NMR has a number of uses within it. However, challenges remain for the simultaneous measurement of rheological and NMR parameters.