“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.
Articles and Columns
“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).
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.
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.
This article describes an application of spectral imaging for the differentiation of tumour and normal cells. The authors also introduce the concept of a spectral barcode, which has had success with some tissues and has potential in others.
With continuing food scares around the world, food producers need every tool they can get to prevent contamination of their products at every stage of production. Hyperspectral reflectance imaging in the NIR combined with chemometrics shows much promise for the detection and identification of foreign bodies among food grains.
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.
John Hammond reports on important developments at the ISO Committee on Reference Materials (ISO/REMCO) annual meeting.
Robert Lancashire reports from the Chemical Information Division (CINF) of the American Chemical Society meeting at their recent 246th ACS National Meeting and Exposition.
The single cell Raman spectrum (SCRS) enables cell probing and sorting to study phenotypes and ecophysiology of single cells and explore individual cells in situ in a label-free and non-destructive manner.
In resonance Raman scattering (RRS), the amount of structural and chemical information deduced can be increased by analysing the polarisation of the inelastically scattered light, including the degree of molecular aggregation in bio-molecules in their natural environment.
There are a number of approaches, and by combining FT-IR imaging methodology with microfluidics devices, the opportunity to study live cells by FT-IR imaging in controlled environments is now possible.
This article explains the challenges in pesticide residue analysis of samples associated with suspected poisoning incident investigations, including the wide range of specimens and pesticides that need to be considered.
Now that Tony understands wavelets, he is in the perfect position to explain them to the rest of us! Whilst wavelet compression is an interesting and popular method, it is worth confirming that there is a real benefit in using them compared to FT compression, especially for near infrared spectra where there are few regions of flat baseline.