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.
Articles and Columns
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.
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.
Thiabendazole (TBZ) is a chemical fungicide and parasiticide used to prevent mould, blight and other diseases resulting from long transportation and storage, largely used as an ingredient in waxes applied to the skins of citrus fruits. The authors describe their work using near infrared-surface-enhanced Raman spectroscopy and conventional Ag nanoparticles, which showed that TBZ was found both on organic fruit and at levels higher than regulations allow.
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.
In this article we learn of a new definition for “bath salts”, and how modern mass spectrometry instrumentation can provide rapid and quantitation of these “designer” drugs.
Tony (A.N.) Davies is getting excited by GHz NMR. These new high fields offer tantalising new areas of research but at a cost that generally requires their purchase by Government-funded centres of excellence. He argues that continued funding of such projects is essential, especially in difficult economic times.
Peter Jenks and John Hammond describe how the important ISO 17025 standard has developed, and point out that a review for the third edition of the standard will start soon. All those with an interest in quality standads—an increasing number of us—should make sure their voice is heard at their local standards body.
Both the size and chemical composition of airborne particles have an effect on human health. Whilst the effects of size have been much studied, many of the toxic chemicals in particles are at very low concentration and have been less studied. Monitoring their composition and concentration over time helps to determine their source. Synchrotron radiation-induced XRF spectrometry proves to be a good tool for this purpose.
Tip-enhanced Raman spectroscopy (TERS) and tip-enhanced Raman mapping (TERM) can be used advantageously to investigate the carbon allotropes graphene and single-walled carbon nanotubes, with a spatial resolution in the nanometre range
Bread is the major contributor to Na intake in the human diet. For this reason, it is expected that lowering the amount of salt in bread may lead to a substantial reduction in the sodium intake. However, lowering the amount of salt in bread has an impact on the flavour. Using LIBS, a fast and easy-to-use method could be set up to determine Na distribution in baked bread as an innovative tool to help the development of methods to reduce total sodium content in bread.
Tony (A.M.C.) Davies starts a review of the chemometric ideas that have most excited him over the last 30 years. In this column, he looks at the use of Fourier transformation for data compression. FT can also provide the side benefit of reducing high-frequency noise.
Fuels and the taxes raised from their sale are a big business around the world. To control smuggling, counterfeiting, theft and product diversion, markers can be placed in the fuel. The use of a SERS active compounds as markers is described as well as the development of a portable instrument for detection of the markers in the field.
Many analytical methods have been used to control the quality, authenticity and origin of fresh fruit. NMR methodologies yield a comprehensive metabolic profile, provide direct structural information regarding individual metabolites in the mixture and also give information regarding the water state in the tissue. This is useful in discriminating various fruits varieties, in investigating nutritional properties, in monitoring the development of the fruit and in assessing the optimum harvesting time.
Chemical modification of wood by methods such as acetylation is required to improve characteristics such as photosensitivity and combustibility, and to provide harmonisation of wood properties in order to avoid swelling and shrinking and to improve biodegradability. The authors describe the use of mid and near infrared spectroscopies to monitor chemical changes due to acetylation is described.