Articles and Columns

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.

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 PO₄^3– 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.

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

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.

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.

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.

Tony Davies continues his quest to find out what you all need to work more efficiently. You will remember that in the last issue, Tony introduced his survey to discover what developments were needed in spectroscopy by readers. Some of the initial responses are explored, and Tony finds that he has opened a “can of worms”.

Different spectroscopic techniques have been combined to provide additional and complementary information for decades. Increasingly, this is being expanded beyond just two techniques and may include spatial/imaging information as well. All of which bring their own challenges. In “Multimodal imaging of cells and tissues: all photons are welcome”, David Perez-Guaita, Kamila Kochana Anja Rüther, Phillip Heraud, Guillermo Quintas and Bayden Wood report an example of these new approaches. They look at the use of infrared, Raman and X-ray fluorescence spectroscopies to obtain combined imaging data of whole algal cells and discuss how to overcome the challenges.

John Hammond updates us on recent developments with the ISO 17xxx series of standards. John continues with news of standards particularly relevant to readers.