Informing Spectroscopists for Over 40 Years

Articles and Columns

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Spectroscopy is widely used in forensics, but the determination of the age of documents was one application I had not considered. With a huge variety of papers and inks available, each with their own ageing profiles, and with such ageing depending on environmental factors, the determination of the age of a document is not straightforward. However, infrared spectroscopy and chemometrics may have the answer.

Jacques Thierie’s article raises a seemingly impossible observation: that in some cases, transparency can exceed 100 %.

Tony raises the question of whether those implementing change consider sufficiently the effects on those who need to implement it or who will be affected by it. I am sure that this has wider implications than just in industry and business.

Kim Esbensen challenges commercial laboratories to add primary sampling to their range of responsibilities. Kim’s “tale” of two fictional laboratories should certainly provoke some comment, and concludes in the next issue.

Peter Jenks makes a welcome return to the Quality Matters Column and raises the radical idea of secondary producers of certified reference materials paying for the use of the primary CRMs. How may this affect the supply and price of secondary CRMs?

The story of Pierre Gy, who founded the Theory of Sampling (TOS), is a remarkable one, and his work is still the basis of representative sampling today.

Nick Polfer gives an excellent introduction to the recent technique of infrared ion spectroscopy. Ions held in the ion trap of a mass spectrometer can be probed with a tuneable light source, and its photodissociation studied as a function of the photon frequency. Nick believes that the technique will make an impact in small molecule analysis, such as metabolites, drugs and classes of molecules containing many isomers.

Clemens Anklin gives a short history of the commercial and technical development of NMR. From the first measurement of nuclear spin in 1937 by Rabi and his 1943 Nobel Prize to recent developments in small NMR spectrometers and instrument company changes.

FAIR, which stands for Findable, Accessible, Interoperable, Reusable, is an essential framework for the future of analytical data. Tony has taken the opportunity of a recent conference in Amsterdam to update readers on FAIR and how it affects spectroscopic data.

Photo of mould on cheese

The last sampling columns have focused on the advantages the Theory of Sampling (TOS) can bring to companies, producers and manufacturers significantly reducing costs due to inferior sampling, and maximising efficiency and logistics. Here instead we take a look at sampling from the point of view of buyers, consumers and from a broader societal perspective, exploring the economic benefits and other advantages (e.g. transparency) that can be obtained through proper sampling. We address the point of view of the ultimate users and beneficiaries of TOS, on the market place or elsewhere. We are going to explore the other side of the coin, the one linked to the ethical and moral obligations that pertain to decision-makers of responsible public and governmental bodies, which indeed should apply equally also to producers and manufacturing companies.

This column explores the initial results extracted from the survey in the last issue into the training the next generation of colleagues currently receives in analytical chemistry.

Photo of caries in human teeth.

In this work we demonstrate the suitability of confocal Raman microscopy for the characterisation of carious dental tissues. Samples of enamel and dentine, presenting carious lesions in different stages of progression, were evaluated by comparing the depolarisation ratio of the PO43– symmetric stretching band at 959 cm–1 in the different tissues. Both line and area scans were performed to gauge these variations. Moreover, the obtained results were compared with the tissues’ behaviour when interacting with ultraviolet radiation, namely the induced fluorescence in some tissues. The depolarisation ratio has proven to be a valuable tool in recognition of demineralisation of both enamel and dentine due to caries. The analyses of the collagen bands in the dentine sample turned out to be more difficult to evaluate due to high fluorescence in the carious region.

Photo of paper production in a paper mill

Pentti Minkkinen and Kim Esbensen present case histories and examples all focusing on the potential for economic loss or gain—by following, or more importantly, by not following TOS.

John Hammond updates us on news from the latest ISO/REMCO meeting and implementation of the new 17000 series standards.

Do you educate students who may go on to work in industry, or are you involved in assimilating students into your team? If so, you will really want to read this issue’s Tony Davies Column. Tony and co-authors, Jennipher Dania and Joachim Zahradnik, are undertaking two surveys to explore this area: one for Academics and one for Industrialists. Please do spend the very short time needed to complete one (or both) of these surveys.

Significant research is underway globally into both improving corrosion protection as well as removing chemicals of concern from existing corrosion protection coatings. This is because the cost of corrosion in developed economies has been consistently shown to lie in the range 2–4% of Gross National Product.

Nanomaterials find widespread applications in many fields of science and nanotechnology, especially as catalysts in the chemical, bio-nanotechnology, nano-electronics and pharmaceutical industries. Understanding the physical and chemical properties of nanoscale materials is important, not only because of the fascinating nature of the subject, but also due to their potential applicability in almost every branch of science and technology. Nanostructured materials offer interesting properties, because at the atomic or molecular scale, the physical properties of a material become size dependent due to the quantum confinement and surface states effects.

 Illustration of a thin film solar cell based on a CIGS [Cu(In,Ga)Se2] absorber layer

In this article the question of the certification of calibration samples for the characterisation of advanced thin film materials is addressed within the framework of reliable process control or quality management purposes. Reference measurement techniques can be used in order to address the gap in appropriate certified reference materials (CRMs) for thin film analyses. They allow for qualifying out-of-production samples originating from an operating production line as calibration samples. As a template for this procedure, CIGS [Cu(In,Ga)Se2] layers, that are absorber layers for high efficiency thin-film solar cells, have been used for establishing and validating reference-free X-ray fluorescence (XRF) analysis and Auger-electron spectroscopy (AES) as reference measurement techniques.

Sampling takes place every day in everybody’s daily life. Consciously or unconsciously, we all take decisions regarding how to select and collect the things we need, be those vegetables or coffee in the supermarket, or material for academic research projects—with everything in between. Those who have been curious enough to reflect on everyday decision-making processes, discovered immediately that sampling decisions often make all the difference. This is why an incipient theory started to be elaborated. One individual, more brilliant than others, made a giant step forward in the evolutionary thinking on sampling and developed what became the Theory of Sampling (TOS); his name was Pierre Gy. Here, we discuss cases both pro et contra TOS.

Karin Engström, LKAB mining, Kiruna, Sweden, continues to present illuminative cases from process industry. Here she reveals more from her ongoing PhD project showing application of variographic characterisation for on-line continuous control of process sampling systems, including the one that was validated according to current ISO standards guidelines in the previous column (monitoring a particular iron ore pellet stream). Together, the cases presented constitute a broad didactic showcase of the power of variographic analysis and problem-specific interpretations.

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