A novel setup is described in which we combined the separation of a volatile substance from a sample with a complex matrix on the basis of a microdiffusion process with a kinetic online spectrometric monitoring of the reaction in the receptive medium at 365 nm. The fruit juice was selected as a model for testing the performance of the setup in reallife applications.
F.06 Development of a new product
COBISS.SI-ID: 35545605Surface oxidation of the duplex stainless steel DSS alloy 2205 was studied by X-ray photoelectron spectroscopy (XPS) and SEM imaging. The experiments were performed on the alloy after controlled oxidation with oxygen atoms created in an inductively coupled plasma. Experiments were performed at temperatures from room temperature up to 700 [compositum]C. Compositions of the modified oxidized surfaces were obtained from XPS survey scans, and the chemistries of selected elements from higher energy resolution scans of appropriate peaks. The morphologies of the surfaces were obtained using field emission scanning electron microscopy at different magnifications, up to 20,000x. Different Fe/Cr/Mn oxidized layers and different oxide thicknesses were observed and correlated with temperature.
F.09 Development of a new technological process or technology
COBISS.SI-ID: 707498Essential oils are in the pharmacopoeas defined as volatile constituents of plants separated by hydrodistillation (HD), steam distillation (SD) or pressing. Solvent extraction (SE) is used for more delicate essential oils. Modern established and emerging extraction techniques for essential oils aim to overcome these problems. Their advantages, disadvantages and applicability are discussed in this review, which covers mainly the scientific literature published in the last decade.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 33715461Until recently, applications of spectral imaging in heritage science mostly focused on qualitative examination of artworks. This is partly due to the complexity of artworks and partly due to the lack of appropriate standard materials. With the recent advance of NIR imaging spectrometers, the interval 1000–2500 nm became available for exploration, enabling us to extract quantitative chemical information from artworks. In this contribution, the development of 2D NIR quantitative chemical maps of heritage objects is discussed along with presentation of the first quantitative image. Further case studies include semiquantitative mapping of plasticiser distribution in a plastic object and identification of historic plastic materials. In the NIR imaging studies discussed, sets of 256 spatially registered images were collected at different wavelengths in the NIR region of 1000–2500 nm. The data was analyzed as a spectral cube, both as a stack of wavelengthresolved images and as a series of spectra, one per each sample pixel, using multivariate analysis. This approach is only possible using wellcharacterized reference sample collections, as quantitative imaging applications need to be developed, thus enabling spatial maps of damaged and degraded areas to be visualized to a level of chemical detail previously not possible. Such quantitative chemical mapping of vulnerable areas of heritage objects is invaluable, as it enables damage to historic objects to be quantitatively visualized. The results of this work was published in the distinguished journal Analytical Chemistry (Washington), and two of the authors (L.C. and M.S.) acquired basic knowledge on the paper chemistry in our research group. They perform now the research on this subject in the Centre of Sustainable Heritage, The Bartlet School of Graduate Studies, University College London.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 35488773Prussian blue (PB) modified titanate nanotubes (PB-TiNT) have been synthesized by the reaction of Fe2+ modified TiNT with hexacyanoferrate(III) ions. The rate constant for heterogeneous catalytic reaction between PB-TiNT and H2O2 was found to be an order of magnitude higher than the values reported for conventionally prepared, electrochemically deposited PB films. On the PB-TiNT modified electrode with subnanomolar surface concentration of PB a stable, reproducible and linear response towards H2O2 was obtained in the concentration range 0.02–4 mM at –150 mV.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 24239655