Doping control authorities and sports drug testing laboratories are frequently confronted with the illicit use of performance-enhancing therapeutics and therefore various analytical strategies have been developed to detect a misused drug and/or its metabolic product(s) in blood or urine specimens. Besides the administration of clinically approved drugs prohibited in sports, new drug candidates currently undergoing early or advanced clinical trials have also been the subject of investigations concerning their prevalence and abuse by athletes.
There is considerable interest in chemical imaging of pharmaceutical tablets since knowledge of the spatial distribution of constituents is critical to ensuring uniformity and consistency of product. Pharmaceutical tablets in general are complex multicomponent blends comprising active ingredients(s) and a variety of inactive substances—the excipients—that are used to aid manufacture and facilitate tablet administration. Thus, in addition to measurement of the spatial distribution of the active drug, there is a need to monitor excipients such as binders, fillers, coatings, lubricants, disintegrants and preservatives. Imaging of organic and inorganic constituents of tablets represents a considerable challenge and no single spectroscopic approach can provide definitive characterisation of all components and/or satisfy key measurement criteria such as sensitivity, specificity, resolution and speed of analysis. With respect to molecular imaging, Fourier transform infrared (FT-IR), Raman and fluorescence microscopies are widely used in the pharmaceutical industry. Indeed efforts have been made to exploit the complementary nature of IR and Raman by merging respective data sets in order “to enable a more complete visualisation of pharmaceutical formulations”. More generally the approach of Clarke et al. termed “Chemical Imaging Fusion” can be extended to elemental imaging given that inorganic compounds and heteroatoms are critical components of formulations.
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.
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.
The problem of detecting, recognising and identifying explosives at significant standoff distances has proved one of the most difficult—and most important—challenges during recent years, being today, one of the most demanding applications of spectroscopic techniques. The limited number of sophisticated available techniques potentially capable of standoff detection of minimal amounts of explosives is based on laser spectroscopy. Of the recently developed techniques, Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) are considered significant for their potential for homeland defence applications.
