X-ray spectroscopy techniques have some advantages over other atomic spectroscopy techniques in the analysis of foods, for instance in not requiring significant sample preparation. Amongst these, TXRF has higher sensitivity and limits of detection in the ng range. The authors look at the analysis of a number of very different foods, including seafood, honey and vegetables.
Articles and Columns
Kim Esbensen and Claas Wagner have produced an extensive Sampling column, on “Representative mass reduction in the laboratory: riffle splitting galore (with or without errors)”. They guide readers through the choice of mass reduction equipment and what needs to be done to ensure representative sampling.
Kim Esbensen and Claas Wagner continue to stress that grab sampling is still an absolute no-no regardless of the size of the sampling device or the sample.
Next year, a new version of ISO/IEC 17025 will be published, which is going to mean changes for all those involved in quality systems. Peter Jenks investigates.
Tony Davies and Steven Brown explore the solid-state nuclear magnetic resonance spectroscopy facilities at the University of Warwick, UK.
This article demonstrates the capability of the near-field method to probe polymer microspheres within a protein matrix, and we present the first IRSR photothermal near-field Fourier transform infrared (FT-IR) spectrum from within an individual biological cell, which establishes the feasibility of hyperspectral mapping at sub-micrometre resolution in a practical timescale.
The CAL(AI)2DOSCOPE (Cryogenic Absorption/Luminescence Alignment Independent Alternative Intermittent Detection Optical µSCOPE) is a microspectrometer that was constructed with the aim to facilitate the correlated investigation of absorption and fluorescence emission properties of nanovolumic protein samples under modulatable actinic illumination.
Whilst the major components of food are usually non-fluorescent, many minor food components that affect its nutritive, compositional and technological quality are fluorescent. Given its sensitivity, ease of use and non-destructive nature, this makes it useful in many applications around monitoring food processing and in fundamental food research.
This article is is a fascinating look into the use of laser ablation inductively coupled plasma mass spectrometry in forensic examination of glass fragments. These are often associated with crime scenes and easily “attach” to any people near them. Thus, they can be used to link criminals to their crime and to provide information on where a glass fragment might have originated.
In this article, it is discussed why International standards need to keep pace with the innovation in analytical equipment and practices.
This article gives a most useful overview of the analysis and sequencing of nucleic acids by matrix-assisted laser desorption/ionisation mass spectrometry, which should interest all readers and may well serve as a useful tutorial article.
Lithium ion batteries power most of the electrical devices we rely on every day. As well as mobile phones, laptops and tablets, they are finding increasing use in vehicles, with electric cars not uncommon on our streets. This article is from a young scientist who has won help for her research through an instrument company’s support programme. You can find out more, read the article and even apply yourself.
There are a number of advantages of Raman microspectroscopy, including its the ease of its application, as in many cases no or very little sample preparation is needed and the experiments are performed at atmospheric pressure.
The study of metabolites in our sewage systems is not new, but there are particular difficulties with identifying the metabolites from new psychoactive substances, or “legal highs”. The authors describe a wide range of sample collection methodologies and their analysis with mass spectrometry.
This column now turns its attention to sampling using a very popular tool, the “sampling spear”. There is much good to be said about spear sampling—and only one thing which is bad. But this is bad enough: spear samplers are very, very difficult to get to produce representative samples! The spear sampling principle can be made representative, but in most practical situations in which spear sampling is used today it manifestly is not. WHY? And more importantly, WHAT can be done about it? This column also turns out to touch on one of TOS’ six governing principles: SSI, Sampling Scale Invariance.
Tony Davies has interviewed Gerard (Gerry) Downey who has just retired from the Irish National Agriculture and Food Research Institute, Teagasc. Gerry will be known to many of you, particularly those who work in the fields of chemometrics, NIR spectroscopy and food & ag. I must have known Gerry for over 25 years and currently work closely with him on the publication of NIR news, so I am particularly delighted that Tony has chosen to highlight his career.
It is not every issue that one of our articles starts with a quotation in medieval English, and it is appropriate as two of our articles cover the use of spectroscopy in cultural heritage. This is yet another field where the rich information provided by spectroscopy, along with its non-destructive nature (for many techniques), portability and ability to generate chemical images make it the answer to many questions. Kate Nicholson, Andrew Beeby and Richard Gameson are responsible for the medieval English at the start of their article “Shedding light on medieval manuscripts”. They describe the general use of Raman spectroscopy for the analysis of historical artefacts, and, in particular, their work on medieval European manuscripts and 18th century watercolour pigments. They stess the importance of checking the actual laser power density to avoid damage to priceless artefacts.
Once again developments in portable instruments lead to greater ease of use and the ability to measure far more samples. They describe the application of FT-IR, NIR and XRF spectroscopies to the development of the National Soils Inventory of Scotland, and their work in developing the use of handheld instruments, particularly FT-IR spectrometers.
Terahertz spectroscopy and imaging of Paleolithic cave etchings, 14th century paintings in a church and a mid-20th century Italian painting are all described. This helps demonstrate the versatility of the technique as well as its potential in cultural heritage preservation.
This article looks at the use of Raman and XRF spectroscopies to investigate the different deterioration processes caused by marine aerosols. These techniques can detect the decay compounds and the original composition of the different materials from historical buildings close to the sea, which can then be used to explain the reactions that take place on them. This helps in the development of remedial actions and preventive conservation strategies for historical buildings.