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Reliable interpretation of the changes occurring in the samples during their heating is ensured by using more than one measurement technique. This is related to the necessity of eliminating the uncertainty resulting from the interpretation of data obtained by two or more single techniques based on the study of several samples analyzed at different times. Accordingly, the purpose of this paper is to briefly characterize thermal analysis techniques coupled to non-thermal techniques, most often spectroscopic or chromatographic. The design of coupled thermogravimetry (TG) with Fourier transform infrared spectroscopy (FTIR), TG with mass spectrometry (MS) and TG with gas chromatography/mass spectrometry (GC/MS) systems and the principles of measurement are discussed. Using medicinal substances as examples, the key importance of coupled techniques in pharmaceutical technology is pointed out. They make it possible not only to know precisely the behavior of medicinal substances during heating and to identify volatile degradation products, but also to determine the mechanism of thermal decomposition. The data obtained make it possible to predict the behavior of medicinal substances during the manufacture of pharmaceutical preparations and determine their shelf life and storage conditions. Additionally, characterized are design solutions that support the interpretation of differential scanning calorimetry (DSC) curves based on observation of the samples during heating or based on simultaneous registration of FTIR spectra and X-ray diffractograms (XRD). This is important because DSC is an inherently non-specific technique. For this reason, individual phase transitions cannot be distinguished from each other based on DSC curves, and supporting techniques are required to interpret them correctly. [ABSTRACT FROM AUTHOR]

Reliable interpretation of the changes occurring in the samples during their heating is ensured by using more than one measurement technique. This is related to the necessity of eliminating the uncertainty resulting from the interpretation of data obtained by two or more single techniques based on the study of several samples analyzed at different times. Accordingly, the purpose of this paper is to briefly characterize thermal analysis techniques coupled to non-thermal techniques, most often spectroscopic or chromatographic. The design of coupled thermogravimetry (TG) with Fourier transform infrared spectroscopy (FTIR), TG with mass spectrometry (MS) and TG with gas chromatography/mass spectrometry (GC/MS) systems and the principles of measurement are discussed. Using medicinal substances as examples, the key importance of coupled techniques in pharmaceutical technology is pointed out. They make it possible not only to know precisely the behavior of medicinal substances during heating and to identify volatile degradation products, but also to determine the mechanism of thermal decomposition. The data obtained make it possible to predict the behavior of medicinal substances during the manufacture of pharmaceutical preparations and determine their shelf life and storage conditions. Additionally, characterized are design solutions that support the interpretation of differential scanning calorimetry (DSC) curves based on observation of the samples during heating or based on simultaneous registration of FTIR spectra and X-ray diffractograms (XRD). This is important because DSC is an inherently non-specific technique. For this reason, individual phase transitions cannot be distinguished from each other based on DSC curves, and supporting techniques are required to interpret them correctly.

The growing release of technology-critical elements (TCEs): Ga, Ge, In, Nb, Ta, Te, Tl, and most of the platinum group elements (PGEs), and rare earth elements (REEs) requires the understanding of their mobility, reactivity and chemical transformations in the environment which are critically dependent on their chemical form (speciation). The total concentrations of these elements at the trace levels make their speciation analysis challenging. Coupled techniques combining a high resolution chromatographic separation with ultrasensitive element-specific detection by inductively coupled plasma mass spectrometry (ICP MS) often offer the unique possibility of accessing the information on the identities and concentrations of individual metal species present in environmental samples. This paper reviews the advantages and limitations of these techniques to TCEs speciation and highlights the development trends in analytical methodology that may contribute to our understanding of the risks associated with the increasing environmental presence of TCEs. [ABSTRACT FROM AUTHOR]

Currently, there has been a growing interest of zeolite materials for industrial and scientific purpose. Synthetic zeolites are more often used than natural ones due to its higher purity and more uniform particle sizes. Numerous investigations are conducted in searching of inexpensive raw materials suitable for zeolite synthesis. Moreover, the temperature, pressure, times and SiO2/Al2O3 ratio are the most important parameters which play key roles in the synthesis processes. Due to such a large number of factors that affect the process, zeolite synthesis has been undergoing constant development. Nowadays, researchers focus on the methods of synthesizing zeolites at ambient temperature and pressure. Metakaolin and tuff are natural raw materials which can be turned into a brand new class of synthetic zeolites. However, each requires different method of synthesis in order to obtain a material with best physical properties. This paper discusses the process of alkaline activation of synthetic zeolites from natural raw materials: volcanic tuff excavated in Filipowice and metakaolin obtained from Rominco company. Two methods: fusion and low-temperature synthesis, were used in the presented research. Moreover, the physical properties of raw materials and zeolites obtained were shown. Based on the XRD analysis, it was verified that materials after the synthesis process contained zeolites A, Na-X and faujasite-Na. Furthermore, the dehydration and thermal decomposition phenomena of the tuff and metakaolin before and after the synthesis process were determined by coupled TG/MS techniques. [ABSTRACT FROM AUTHOR]

This review is focused to cover the application of different analytical techniques for the determination of metals and metalloids in different categories of dietary supplements. Atomic spectrometric methods based on flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry, atomic fluorescence spectrometry, X–ray fluorescence spectrometry and plasma–based techniques such as inductively coupled plasma optical emission spectrometry and inductively coupled plasma–mass spectrometry are reviewed because a considerable amount of research is presently performed in this field. Even when much less reported in the literature, the application of neutron activation analysis, isotope dilution mass spectrometry and hyphenated methodologies for speciation studies based on the use of separative techniques in combination with specific detectors are also discussed. This survey contains 46 references and covers mainly the literature published over the last fifteen years. [ABSTRACT FROM AUTHOR]

Thermal analysis has a wide range of applications in pharmaceutical industry, in designing new molecules, control of raw materials, stability, compatibility studies, and development of new formulations. This paper evaluates the thermodynamic properties of two second generation G2 carbosilane dendrimers with peripheral ammonia groups by differential scanning calorimetry and TG/FTIR coupled techniques. The physical transformations have been detected and their thermodynamic characteristics have been estimated and analyzed. Both dendrimers are stable up to 150 °C, have the Tg at 75 and 59 °C and melting temperatures at 113 and 128 °C, respectively. The decomposition process proved to be very complex and takes place in three steps in nitrogen atmosphere and four steps in air, for both types of dendrimers. IR spectroscopic analysis was used to observe the evolution of the gaseous products versus temperature. [ABSTRACT FROM AUTHOR]

Abstract: This study is a large project initiated by the French Nuclear Agency, and concerns the development of a new electrolyte system for the separation of lanthanides by isotachophoresis. This new system is based on a leading electrolyte that incorporates 2-hydroxy-2-methylbutyric acid as complexing agent. The optimization of separation conditions (complexing agent concentration, pH, capillary dimensions, injection conditions, and current intensity) performed by experiments on a commercial capillary instrument with contactless conductivity detection, which allows to improve the separation of 13 lanthanides (La to Lu, except Pm and Ho). We have also directly coupled the isotachophoresis to an inductively coupled plasma mass spectrometer to visualize the mono-elementary elution bands and demonstrate the potentiality of the method for isotope ratio measurements. The application to a simulated solution representative of a fraction of fission products present in a MOX spent fuel is presented in this paper to demonstrate the possible application in future on nuclear fuel samples. [Copyright &y& Elsevier]

Abstract: Crude extracts of roots and stems of Polygonum cuspidatum Sieb. and Zucc. and Polygonum sachalinensis F. Schmidt ex Maxim from China and Switzerland were analyzed by online HPLC/UV/ESI-MS to ascertain the phytochemical differences between the original and invasive exotic varieties. A total of 36 constituents were identified by comparing their retention times, UV data, mass spectra with those of standards or with literature data. Certain constituents, such as flavanol gallate dimers, were reported for the first time from these species. The relative quantities of the major compounds (emodin glucoside, piceid, resveratroloside and piceatannol glucoside) differed in the samples of the Polygonum species from China and from Switzerland. Phenylpropanoid glucosides were the main constituents of the roots and stems of P. sachalinensis, while the roots of P. cuspidatum were characterized by the presence of stilbenes and anthraquinones. [Copyright &y& Elsevier]

Metal ions play a fundamental role in the chemistry of life. The understanding of the molecular bases of the living process requires the knowledge of the correlations existing between metal ions and the genome and the derived -omes: transcriptome, proteome, and metabolome. An indispensable step on this way is the characterization of the coordination environment of metal ions present and the identification and quantification of metal-containing chemical species. The ensemble of research activities related to metal ions in biological systems has been recently referred to as "metallomics" [1]. The progress in this field is largely dependent on the high-throughput acquisition of multielement and -species analytical data in biological samples. The paper gives a brief overview of the state of the art of analytical techniques and methods for the multielement quantitative analysis of biological microsamples, and for the detection, identification, and quantitation of metal-containing proteins and low-molecular-weight metabolites. The potential contribution of molecular biology techniques in terms of linking information on metals and metal-species to the genome of an organism is highlighted. [ABSTRACT FROM AUTHOR]

Abstract: A simple innovation is proposed in this work: to use interface (transfer line, TL), which allows quantitative mass transfer between two gas chromatographs. This approach assumes that one chromatograph serves as a conventional GC apparatus and the second one only as a thermostat with the appropriate detector(s) mounted. Two possible applications of the TL were tested: an “inlet–TL–detector” system and a system for dual-detection analysis, i.e. mass spectrometry and atomic emission detection. Results obtained for both of the systems show that the interface enables effective connection of two independent chromatographs. The transfer line is a manufacturer-independent innovation (with its own electronics), easy to set up and maintain. [Copyright &y& Elsevier]

In this paper, we present a coupled calculation technique based on space segmentation for the calculation of radiation from tilted rectangular waveguide slot antennas. The basic idea of the method is the segmentation of the antenna into two space regions: an internal one, formed by the waveguide, and an external one, consisting of the half space where the slots are radiating into. The internal problem is solved using finite element method, while analytical calculations are performed in the external domain. Frequency-dependent behaviour of the analyzed antenna is also investigated. Measurements taken in the 2.4- and 5.8-GHz ISM frequency bands were found to be in a good agreement with the calculated results. [ABSTRACT FROM AUTHOR]

Abstract: Three different computational techniques were applied to wave propagation problems. Those techniques were the lattice Boltzmann method, finite element method, and cellular automata. The formulation of each technique was presented, and the coupling procedures of those techniques were also presented. For example, a part of the problem domain was solved using one analysis technique while the other part was analyzed by another technique. Such coupled techniques may overcome the difficulties that a single technique has, and they may also provide their own advantages of two different methods in a single analysis depending on application problems. For example, one technique is computationally more efficient while another is useful to model a complex or irregular shape of domain. Combining the two techniques will be beneficial to solve a complex domain shape with computational efficiency. The accuracy of the different techniques including the coupled methods was numerically demonstrated by comparing their solutions to other solutions available for wave propagation problems in 1-D and 2-D. [Copyright &y& Elsevier]

Abstract: In recent years, capillary electrophoresis has increasingly been used for selenium speciation. This review reports recent progress in this field with special focus on separation conditions, detection systems and interfaces. We also review relevant applications. [Copyright &y& Elsevier]

Phenolic compounds, such as phenolic acids, flavonoids, flavonoid glycosides, and resveratrol, were chromatographed on thin-layers of silica in various eluent systems. Systems with the highest selectivity were chosen. Also, reversed-phase HPLC systems were optimized for the separation of investigated compounds and most the selective system was applied for the separation of two phenolic extracts - Polygonum avicularis and Polygonum hydropiper. Partly separated fractions were evaporated and dissolved in methanol. Fractions with partly separated phenolic compounds were spotted onto the silica layer and developed in an appropriate eluent system. After drying, the plate was derivatised with the Naturstoff reagent and videoscanned. Several phenolic compounds were identified, according to their retention coefficients in both systems. [ABSTRACT FROM AUTHOR]

Thermal treatment of torasemide form A resulted in several effects which were divided into five steps. These were investigated and discussed applying TG-MS and TG-FTIR with additional information derived from SEM, hot-stage and FTIR microscopy. The investigated crystal form of torasemide represents a mixed solvate including ethanol and water. Its desolvation, the solid-solid transformation into the anhydrate mod. II and the melting of this anhydrate is elucidated using thermal analysis and microscopic observations (FTIR and hot-stage microscopy). The released and evaporated solvents were determined with coupled techniques. On further heating the structural identification of evolved gases allowed the analysis of the degradation pathway of torasemide up to 340°C. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNCs) self-assemble and can be flow-assembled to liquid crystalline orders in a water suspension. The orders range from nano- to macroscale with the contributions of individual crystals, their micron clusters, and macroscopic assemblies. The resulting hierarchies are optically active materials that exhibit iridescence, reflectance, and light transmission. Although these assemblies have the potential for future renewable materials, details about structures on different hierarchical levels that span from the nano- to the macroscale are still not unraveled. Rheological characterization is essential for investigating flow properties; however, bulk material properties make it difficult to capture the various length-scales during assembly of the suspensions, for example, in simple shear flow. Rheometry is combined with other characterization methods to allow direct analysis of the structure development in the individual hierarchical levels. While optical techniques, scattering, and spectroscopy are often used to complement rheological observations, coupling them in situ to allow simultaneous observation is paramount to fully understand the details of CNC assembly from liquid to solid. This Review provides an overview of achievements in the coupled analytics, as well as our current opinion about opportunities to unravel the structural distinctiveness of cellulose nanomaterials.