TiO2 is widely used as a sunscreen UV filter and as a colouring agent in all types of cosmetic products. TiO2 has recently captured the attention of the scientific community since its safety assessment has been placed again under consideration. Inductively-coupled plasma atomic emission spectrometry (ICP-AES), square wave voltammetry (SWV) and sedimentation field-flow fractionation (SdFFF) are described in this article to characterise and quantify the TiO2 particles inside six commercial foundation creams.
Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful analytical tools used to probe details of molecular structure and dynamics. It requires very high magnetic fields and, hence, generally uses extremely large, powerful magnets. The advent of small, powerful magnets has allowed much less expensive low resolution NMR instrumentation to be designed, making it feasible to measure commercially important characteristics of dispersion behaviour and performance, including the wetted surface area of particulate suspensions and emulsion droplet size. An important additional practical application is the ability to determine competitive adsorption and/or displacement of polymers and surfactants at interfaces. This article presents a brief overview of these new approaches together with an example of each measurement.
This article shows that NIR spectroscopy offers the potential for bioprocess manufacturing companies to limit the variability in the biological production process, thereby increasing the yield and reducing the number of errors.
Applications of mass spectrometry in the clinical area have increased significantly in recent years and continue to expand. The complexity of analyses has also increased, with work being undertaken in clinical labs that would have been the reserve of research labs a few years ago.
This article surveys developments in the applications of Raman spectroscopy and the design of probes for use in endoscopes for the detection of early cancers in the throat and stomach.
BBCEAS is a new cavity-based absorption technique that uses broadband sources rather than lasers. This offers potential improvements in signal-to-noise but often lower spectral resolution compared to techniques where the laser wavelength is scanned. The article concentrates on liquid-phase applications, an interesting new area since most cavity-based absorption studies have been performed on gas-phase species up to now.
As nanotechnology grows in importance, the need for rapid, easy and automated analytical methods to investigate new nanomaterials increases. Near infrared (NIR) spectroscopy has the potential to replace numerous methods for the investigation of a wide range of nanostructured materials and with particular potential in the area of PAT.
M. Hässig,a K. Altwegg,a H. Balsiger,a B. Schläppi,a J.J. Berthelier,b B. Fiethe,c S.A. Fuselier,d J. De Keysere and M. Rubinf
aPhysikalisches Institut, University of Bern, Sidlerstr. 5, CH-3012 Bern, Switzerland
bLATMOS, Saint Maur, France
cInstitut of Computer and Network Engineering, Technische Universität Braunschweig, Germany
The authors describe the use of a range of complementary methods to explore cellular, physiological and behavioural mechanisms underlying Al accumulation and toxicity, and its eventual fate, using the pond snail as a model organism.
Raman spectroscopy is to be used as one of the analytical techniques for the European Space Agency’s ExoMars mission to identify the geological and biogeological spectral signatures that could herald the presence of extinct or extant life on Mars. The article looks at the benefits of Raman spectroscopy for this and the research on Earth to build knowledge of the spectra of organisms living in extreme conditions here.
This article describes the analysis of cells from the pulp of the feather by IR spectroscopy and the possibility of using infrared imaging of intact eggs to determine bird gender.
Nati Salvadó, Salvador Butí and Trinitat Pradell have used a number of techniques to investigate changes in pictorial techniques in Catalan paintings in the 15th century. The combination of different techniques is of particular value. The use of synchtrotron radiation as a light source is also an advantage.
Dirk Lachenmeier, Marina Gary, Yulia Monakhova, Thomas Kuballa and Gerd Mildau describe “Rapid NMR screening of total aldehydes to detect oxidative rancidity in vegetable oils and decorative cosmetics”. Lipid oxidation produces rancid products, which are both unpleasant and potentially toxic. The authors describe the use of NMR to screen food and cosmetic products. Whilst, vegetable oils were generally found to be in good condition, German women may wish to be careful of their lipstick, especially if they have had kept it for a while!
Roumiana Tsenkova introduces us to the field of “Aquaphotomics” which she has pioneered. The potential information held by water in biological systems coupled with NIR spectroscopy’s ability to extract a large amount of information at once, means that Aquaphotomics may be of great importance in the study of living organisms.
This article discusses how modern inductively-coupled plasma (ICP) technology surpasses the performance of traditionally used atomic absorption spectroscopy (AAS) techniques to ensure optimal fuel quality.
Information on the detailed chemical composition, structure and morphology of environmental particles, and especially airborne particulate matter (PM), facilitate the understanding of their reactivity, sources, transport and changes of chemical species and, hence, prediction of their likely impact on the environment and human and animal health. The analysis techniques for environmental particles can broadly be divided into two groups: bulk (for example, water-soluble ionic content by means of ion chromatography for PM, elemental concentrations by means of X-ray fluorescence spectrometry for all environmental particles, chemical structural information by means of X-ray diffraction for larger environmental particles, such as sediments and sands etc.) and micro-analytical techniques, whereby the character of any single particle can be probed.
The counterfeiting of medicines is an increasing world wide problem as a great danger to public health. Counterfeit medicines are imitations of their authentic counterparts so that both physical characterisation and chemical analysis are required to discriminate between them. In this respect, near infrared (NIR) spectroscopy is ideally suited to screening for counterfeit medicines because it is non-destructive, fast, requires no sample preparation, and provides a fingerprint of the physical and chemical composition of a product.
Spectroscopy is the measurement of the interaction of radiation with matter before or after spectral dispersion. This has been studied variously by physicists and chemists, has wide applications outside these traditional disciplines and cannot be owned by any particular community. The subject embraces both science (including mathematics) and technology (including computing) and contains many examples of differences, not always understood, between these cultures. It illustrates the unchanging and universal character of the relevant science, which is increasingly revealed by advances in the relevant technology.
We conceive selected ion flow tube mass spectrometry, SIFT-MS, primarily as a real-time, absolute, analytical technique that can meet the challenge of the immediate analysis of humid exhaled breath for rapid clinical diagnosis and therapeutic monitoring. This objective has certainly been achieved and the application of SIFT-MS has quickly been expanded into many other areas where real time, immediate analyses of trace compounds in air are desired, as we have demonstrated in recent reviews and which we summarise at the end of this article.
We have previously investigated the topographic and quantitative changes in the distribution of trace metals in spinal cords from ALS and control patients. X-ray fluorescence microscopy was used to investigate their metallic nature and distribution in single nerve cells. A deeper understanding of the neurodegenerative processes in ALS requires focus on the biochemical changes occurring in nervous tissue of such a disorder. For this purpose, we have undertaken an infrared microspectroscopy study. While metals are suggested to play a pivotal role in the pathogenesis of ALS, they typically do not occur in tissues as free ions. This results in the presence of the complex mechanisms of metal ions buffering that protect cells against their toxic effects. Metal homeostasis is regulated by several proteins. Such proteins containing metal cofactor are called metalloproteins.