Mid-infrared spectroscopic imaging is a rapidly emerging technique in biomedical research and clinical diagnostics that takes advantage of the unique molecular fingerprint of cells, tissue and biofluids to provide a rich biochemical image without the need for staining. Spectroscopic analysis allows for the objective classification of biological material at a molecular level.1 This “label free” molecular imaging technique has been applied to histology, cytology, surgical pathology, microbiology and stem cell research, and can be used to detect subtle changes to the genome, proteome and metabolome.2–4
Articles and Columns
John Hammond and Chris Burgess are also in the middle of a multi-part contribution to the Quality Matters column. “…that’s what I thought you said?” looks at further misundertandings in terminologies surrounding Reference Materials, and sets the record straight.
Another area of application of XRF, “Determination of elemental distribution or heterogeneity by X-ray fluorescence”, is considered by Christopher Shaffer and Didier Bonvin. The ability of modern X-ray spectrometers to perform small spot analysis as well as mapping has opened up new applications in non-homogeneous samples. The authors show applications in metals, precious alloys as well as rocks.
Knowledge about the particles in the air is important because of their effect on our health and their impact on our climate through cloud formation and transport of nutrients into the oceans. Ursula Fittschen describes “Strategies for ambient aerosols characterisation using synchrotron X-ray fluorescence: a review”. This technique can provide elemental determination and speciation of aerosol particulates with limits of detection in the pg m–3 range for many elements.
In the Tony Davies Column, Tony (A.N.) Davies and Mohan Cashyap introduce us to the potential for Cloud Computing in the lab. This is the first of a two-part contribution, and, for the second part, they need your help with your experiences of Cloud Computing in your lab or organisation.
The analysis of turbid samples is increasingly important, not least due to their widespread occurrence in natural samples. Dmitry Khoptyar, Sören Johansson, Staffan Strömblad and Stefan Andersson-Engels show “Broadband photon time-of-flight spectroscopy as a prospective tool in biomedicine and industrial process and quality control”. The authors describe their recent development of a broadband spectrometer for evaluation of absorption and scattering spectra of very diverse turbid materials in the visible and close-near infrared (NIR) regions and its application with milk, cheese and paper samples.
It is important that places of archaeological and architectural importance need to be explored without damage. Atomic Dielectric Resonance (ADR) can be used for identifying sub-surface geological features. This technology1 uses a novel coherent beam, which has been used in the oil, gas and water industries, to provide information on what lies beneath the earth’s surface, without the need to drill cores.
“Spectral database for postage stamps by means of FT-IR spectroscopy” by Eleonora Imperio, Gabriele Giancane and Ludovico Valli will be of great interest. As well as helping to detect forgeries, FT-IR has been used to create a database which also charts the history of the technology used to create stamps. Quite rightly, they are considered by many to be works of art.
“Emerging sampling approaches for Raman analysis of foods” by Nils Kristian Afseth, Matthew Bloomfield, Jens Petter Wold and Pavel Matousek describes how a number of instrumental developments are enabling Raman spectroscopy to find increasing applications in food analysis. They show how Spatially Offset Raman Spectroscopy (SORS) is being used to analyse quality parameters in salmon, including the content of fat, its fat composition and the content of carotenoids. Traditionally, the preserve of NIR spectroscopy, Raman may increasingly be used for the analysis of food and other biological matrices.
Tony (A.M.C.) Davies looks at Multiple Linear Regression (MLR) this issue, as well as expressing his opinions about Principal Components Regression (PCR) and Partial Least-Squares (PLS).
“Membrane inlet mass spectrometry for in situ environmental monitoring” by Simon Maher, Fred Jjunju, Iain Young, Boris Brkic and Stephen Taylor looks at a technique that is 50 years old but is now being applied for field analysis. As well as a brief overview of the technique, they show how it can be used to monitor oil-in-water levels before discharge from oil termini.
Malvina G. Orkoulaa and Christos G. Kontoyannisa,b
aDepartment of Pharmacy, University of Patras, Rio-Patras, Greece. E-mail: firstname.lastname@example.org
bICE-HT/FORTH, PO Box 1414, University Campus, Rio-Patras, Greece
Tony Davies explains “Terahertz Spectroscopy” and describes some new and interesting applications
The authors give us a “Review of nanoscale infrared spectroscopy applications to energy related materials”. Fuel cells, photovoltaics and specialised polymers for fracking are all considered.
Peter Jenks clarifies “What is a ‘Primary Standard’?”.
Mathieu Duval raises the question “Dating fossil teeth by electron paramagnetic resonance: how is that possible?”. Whilst we are all familiar with 14C dating, the use of EPR is less well known. In fact, there are less than 10 laboratories in the world able to carry out EPR dating of fossil teeth!
“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.
This is a new column on Sampling, edited by Kim Esbensen and Claas Wagner. I really only became aware of the Theory of Sampling (TOS) following conversations with Kim at the NIR-2013 conference in La Grande Motte, near Montpellier, France. I won’t steal Kim and Claas’ thunder by going into detail, but I see this new column as a perfect complement to our others. Ian Michael, editor.
Tony (A.M.C.) continues down the last furlong of his series of Tony Davies Column articles. This issue, he considers principal component analysis (PCA). Using research recently published in the Journal of Near Infrared Spectroscopy, he explains that PCA is a very useful tool but it will not solve all our problems. Two old articles on PCA, including Tony’s concept of the “Data Cake” have been added to the website, are referenced in Tony’s article and can be freely downloaded by readers.
Sotiris Stasinos and Ioannis Zabetakis have used ICP-MS to investigate the cross-contamination of food crops by heavy metals in ground or irrigation water. They show that this can occur easily in certain crops, which has serious health consequences for those consuming the food crop. As a consequence of their work, the European Food Safety Authority (EFSA) has been informed about the accumulation of Cr and Ni in food tubers and is taking action.