Modern Analytical Chemistry Research Articles

The 7th international conference on instrumental methods of analysis: modern trends and applications (IMA 2011)

The 7th international conference “IMA 2011, Instrumental methods of analysis: modern trends and applications” was held from 18–22 September, 2011, in Chania (west Crete), which presents an excellent combination of cultural life, natural beauty (numerous beaches, gorges such as the renowned Samaria gorge, high mountains, biodiversity, etc.), a Venetian old town and many archaeological sites. The conference was held at the Conference Centre of theMediterraneanAgronomic Institute of Chania/Centre International de Hautes Etudes Agronomiques Mediterraneennes (MAICh/CIHEAM). This is a conference centre conceived with respect for the environment, situated 3 km from the centre of Chania on the campus of the institute. IMA 2011 is the seventh conference in this series, which started in 1999 in Chalkidiki, Macedonia, Greece, under the chairmanship of Professor M. Ochsenkuhn-Petropoulou and there has been a conference every 2 years since then organized by different other Hellenic academic institutions. IMA 2011 provided an excellent framework for the presentation of new concepts, instruments, methods, systems and applications in the area of modern chemical analysis. Researchers and scientists from universities, research institutions, state organizations and industry were in attendance and presented their experiences in the current state of the art in the area of instrumental methods of analysis. Furthermore, IMA 2011 provided grounds for graduate and postgraduate students to disclose their projects, discuss scientific collaborations with other groups, as well as to explore employment opportunities. IMA 2011 was organized with the cooperation of two of the most important Cretan institutes: the Technical University of Crete (Analytical and Environmental Chemistry Laboratory) and the MAICh/CIHEAM. Co-organizers were other Hellenic academic analytical chemistry institutions actively involved in former IMA conferences. The conference was opened by Professor Y. Phillis, Rector of the Technical University of Crete. Honorary prizes were awarded to Professor Elo Hansen, Denmark, and Professor Antonius Kettrup, Germany, for their top contributions in the field of analytical chemistry. Presentations were given in the fields of bioanalytics, speciation, sensors, materials science and nanomaterials, mass spectrometry, environmental analysis, chromatography, X-ray analysis and atomic absorption spectrometry over the 5 days of the conference. The scientific framework consisted of 14 sessions, 2 of which were held in parallel. Each session was introduced by a plenary lecture conducted bywell-known invited scientists experienced in the respective fields from all over the world, for example, A. Sanz-Medel (Pulsed radiofrequency glow discharge time-of-flight mass spectrometry for isotopes, elements, molecules and nanostructured materials), R. Lobinski (High-resolution molecular mass spectrometry in the analysis of heteroatom-containing molecules), B.Michalke (Element speciation in neurodegenerative disease investigation—focus on manganese), G. Hieftje (New instruments for mass spectrometry),W. Lindner (Potential of chiral ion exchanger for chromatographic resolution of stereoisomers), and chaired by experts in instrumental methods of analysis. Published in the special paper collection Instrumental Methods of Analysis (IMA 2011) with guest editors Maria OchsenkuehnPetropoulou, Nikos Kallithrakas and Panagiotis Kefalas

Carbon Nanotubes in Sample Preparation

The discovery and implementation of new materials in sample preparation have a significant impact on the development of new analytical methods and often on the instrumentation used in chemical analysis. In recent years, nanostructured materials of different chemical composition, such as nanoparticles, nanowires or nanotubes have received increasing attention. Their introduction in almost every stage of chemical analysis has constituted a significant milestone in modern analytical chemistry. Carbon nanotubes (CNTs) are allotropes of carbon that can be obtained as a single-walled (SWCNTs), or multi-walled (MWCNTs) material with a cylindrical nanostructure. Since their discovery in 1991, they have attracted great attention, because of their unique properties, which make them potentially useful in a wide range of scientific fields, from electronics to medicinal chemistry. In analytical chemistry, CNTs can be used as chromatographic solid phase material, and can therefore be directly involved in any step of chemical analysis. More specifically, due to the porous graphite structure of CNTs, they can be used as sorbents in sample preparation techniques, such as Solid Phase Extraction or Solid Phase Microextraction, for the cleaning up and the pre-concentration of a great variety of analytes in different matrices. Many applications can be found in literature regarding the analysis of phenolic compounds, pesticides, pharmaceuticals, inorganic ions, organometallic compounds, etc. in food, in environmental samples, or in biofluids with the use of CNTs. The objective of this review is to summarize the applications of carbon nanotubes in sample preparation over the past decade.

Analytical sonochemistry; developments, applications, and hyphenations of ultrasound in sample preparation and analytical techniques

Abstract Ultrasonic assistance is one of the great successes of modern analytical chemistry, which uses this energy for a variety of purposes in relation to sample preparation and development of methods for the analysis of numerous contaminants including organic and inorganic compounds. This review will attempt to provide an overview of more recent applications of ultrasound in different environmental and biological samples such as food, soil and water as well as a brief description of the theoretical understanding of this method. Also, the possibility of coupling ultrasound with other analytical techniques will be discussed.

Progress on chemical pattern recognition in traditional Chinese medicines by multidimensional information of metabolic fingerprinting analysis

As a comprehensive, quantifiable identification method based on the chemical composition information of traditional Chinese medicine (TCM), the fingerprint of traditional Chinese medicine has become an internationally recognized effective way to control the quality of natural medicine. Chemical pattern recognition in traditional Chinese medicines is an important breakthrough for the infiltration between fuzzy and pharmaceutical sciences, has been used in the field of quality assessment and control for traditional Chinese medicine. It has solved the problem of comprehensive analysis with multi-dimensional information, and gradually been accepted by more researchers to in-depth study in the further. With the development of modern chemical analysis and computer techniques, there are more technologies were applied to the establishment of fingerprints of traditional Chinese medicine, more chemometric methods have been applied to the data processing of TCM fingerprint, and more quality identification and assessment for TCM to be achieved. And the technology has matured and achieved a lot. In this paper, we make a review for the chemical pattern recognition in traditional Chinese medicines since it be invented, provide a reference for the further research.

Metal–Organic Frameworks for Analytical Chemistry: From Sample Collection to Chromatographic Separation

In modern analytical chemistry researchers pursue novel materials to meet analytical challenges such as improvements in sensitivity, selectivity, and detection limit. Metal-organic frameworks (MOFs) are an emerging class of microporous materials, and their unusual properties such as high surface area, good thermal stability, uniform structured nanoscale cavities, and the availability of in-pore functionality and outer-surface modification are attractive for diverse analytical applications. This Account summarizes our research on the analytical applications of MOFs ranging from sampling to chromatographic separation. MOFs have been either directly used or engineered to meet the demands of various analytical applications. Bulk MOFs with microsized crystals are convenient sorbents for direct application to in-field sampling and solid-phase extraction. Quartz tubes packed with MOF-5 have shown excellent stability, adsorption efficiency, and reproducibility for in-field sampling and trapping of atmospheric formaldehyde. The 2D copper(II) isonicotinate packed microcolumn has demonstrated large enhancement factors and good shape- and size-selectivity when applied to on-line solid-phase extraction of polycyclic aromatic hydrocarbons in water samples. We have explored the molecular sieving effect of MOFs for the efficient enrichment of peptides with simultaneous exclusion of proteins from biological fluids. These results show promise for the future of MOFs in peptidomics research. Moreover, nanosized MOFs and engineered thin films of MOFs are promising materials as novel coatings for solid-phase microextraction. We have developed an in situ hydrothermal growth approach to fabricate thin films of MOF-199 on etched stainless steel wire for solid-phase microextraction of volatile benzene homologues with large enhancement factors and wide linearity. Their high thermal stability and easy-to-engineer nanocrystals make MOFs attractive as new stationary phases to fabricate MOF-coated capillaries for high-resolution gas chromatography (GC). We have explored a dynamic coating approach to fabricate a MOF-coated capillary for the GC separation of important raw chemicals and persistent organic pollutants with high resolution and excellent selectivity. We have combined a MOF-coated fiber for solid-phase microextraction with a MOF-coated capillary for GC separation, which provides an effective MOF-based tandem molecular sieve platform for selective microextraction and high-resolution GC separation of target analytes in complex samples. Microsized MOFs with good solvent stability are attractive stationary phases for high-performance liquid chromatography (HPLC). These materials have shown high resolution and good selectivity and reproducibility in both the normal-phase HPLC separation of fullerenes and substituted aromatics on MIL-101 packed columns and position isomers on a MIL-53(Al) packed column and the reversed-phase HPLC separation of a wide range of analytes from nonpolar to polar and acidic to basic solutes. Despite the above achievements, further exploration of MOFs in analytical chemistry is needed. Especially, analytical application-oriented engineering of MOFs is imperative for specific applications.

Euroanalysis XVI—challenges in modern analytical chemistry

In the International Year of Chemistry, Belgrade was the meeting place for almost 600 participants of Euroanalysis XVI, from 57 countries from all over Europe and overseas. As a broad-spectrum conference on analytical chemistry, held biennially with its venue rotating between European countries, Euroanalysis has established itself as a regular forum of the national societies represented in the Division of Analytical Chemistry of the European Association for Chemical and Molecular Sciences (EuCheMS). The 16th European Conference on Analytical Chemistry, held in September 2011, was hosted by the Division of Analytical Chemistry of the Serbian Chemical Society (SCS), and fully supported by the SCS and its president Ivanka Popovic. The Congress Centre SAVA in Belgrade, located in one of the modern quarters of New Belgrade but still very close to the old historic and charming city centre, provided an excellent venue for the conference, enabling networking at its best on both the scientific and social level. An attractive scientific program was presented under the motto “Challenges in Modern Analytical Chemistry” and there was much to be learnt about the trends and perspectives in the different areas of the analytical sciences. Ten plenary lectures built the framework of the conference. How far can one go with all the available analytical tools? “Diving Deep into the Chemistry of the Human Brain”, the lecture of Jonas Berquist from Uppsala University (Sweden), was a good example of the use of novel techniques for analysis of complex samples, the isolation and enrichment of the non-soluble portion of the proteome membrane-bound proteins from brain tissue. The techniques applied (CPE, 1D gel electrophoresis, in-gel digestion with RP-nanoLC, ESI and high-resolution MS–MS, or direct digestion with RP-nanoLC, MALDITOF/TOF-MS or high-resolution IEF with ESI-nanoLC– MS–MS) are very promising in the study of tissues from the human central nervous system or animal models of neurological diseases. His presentation was awarded the Robert Kellner Lecture prize, established by the Division of EuCheMS in memory of the efforts and contributions of the late Robert Kellner, from Vienna University of Technology, and traditionally sponsored by Springer, Heidelberg. In his lecture “The Role of Accurate Mass Measurement in Chemical, Analytical and Medical Mass Spectrometry” G. Brenton outlined how high-resolution mass spectrometry

Three new compounds from Dictamnus dasycarpus

Phytochemical investigation of the ethyl acetate extracts from root barks of Dictamnus dasycarpus led to the isolation of three new compounds, named as dasycarpusenester A (1), dasycarpusester B (2), dasycarpusacid (3). Their structures were elucidated as (2S)-4-(2,2-dimethyl-5-oxotetrahydrofuran-3-yl)-2-hydroxypent-3-enoic acid methyl ester (1), (2R)-4-(2,2-dimethyl-5-oxotetrahydrofuran-3-yl)-2-hydroxypent-3-anoic acid methyl ester (2), and (2S)-4-(2,2-dimethyl-5-oxotetrahydrofuran-3-yl)-2-hydroxypent-3-anoic acid (3), respectively, on the basis of modern spectroscopic methods and chemical analysis.

Carbon Nanotubes: Application in Pharmaceuticals

The evolution in the manufacturing of carbon nanotubes consists an important milestone in modern analytical chemistry. Since the early days analytical chemists have realised the potential of these materials to be used both in analysis and in preparation of samples and they have used them to analyse a wide range of chemical compounds, with pharmaceuticals being among the most important ones [2]. Carbon nanotubes have been mostly used in electroanalytical chemistry. Due to their unique properties, carbon nanotubes have increasingly been used for the construction of electrochemical sensors aiming to improve their analytical response. Some interesting applications include the electrochemical monitoring of piroxicam in different pharmaceutical forms with multi-walled carbon nanotubes paste electrode [3], the high sensitive voltammetric sensor for qualitative and quantitative determination of phenobarbital as an antiepileptic drug in presence of acetaminophen [4], the voltammetric determination of bisoprolol fumarate in pharmaceutical formulations and urine by using single-wall carbon nanotubes modified glassy carbon electrode [5], the voltammetric determination of cefpirome at multiwalled carbon nanotube modified glassy carbon sensor based electrode in bulk form and pharmaceutical formulation [6].

Interpolation and extrapolation problems of multivariate regression in analytical chemistry: benchmarking the robustness on near-infrared (NIR) spectroscopy data

Modern analytical chemistry of industrial products is in need of rapid, robust, and cheap analytical methods to continuously monitor product quality parameters. For this reason, spectroscopic methods are often used to control the quality of industrial products in an on-line/in-line regime. Vibrational spectroscopy, including mid-infrared (MIR), Raman, and near-infrared (NIR), is one of the best ways to obtain information about the chemical structures and the quality coefficients of multicomponent mixtures. Together with chemometric algorithms and multivariate data analysis (MDA) methods, which were especially created for the analysis of complicated, noisy, and overlapping signals, NIR spectroscopy shows great results in terms of its accuracy, including classical prediction error, RMSEP. However, it is unclear whether the combined NIR + MDA methods are capable of dealing with much more complex interpolation or extrapolation problems that are inevitably present in real-world applications. In the current study, we try to make a rather general comparison of linear, such as partial least squares or projection to latent structures (PLS); "quasi-nonlinear", such as the polynomial version of PLS (Poly-PLS); and intrinsically non-linear, such as artificial neural networks (ANNs), support vector regression (SVR), and least-squares support vector machines (LS-SVM/LSSVM), regression methods in terms of their robustness. As a measure of robustness, we will try to estimate their accuracy when solving interpolation and extrapolation problems. Petroleum and biofuel (biodiesel) systems were chosen as representative examples of real-world samples. Six very different chemical systems that differed in complexity, composition, structure, and properties were studied; these systems were gasoline, ethanol-gasoline biofuel, diesel fuel, aromatic solutions of petroleum macromolecules, petroleum resins in benzene, and biodiesel. Eighteen different sample sets were used in total. General conclusions are made about the applicability of ANN- and SVM-based regression tools in the modern analytical chemistry. The effectiveness of different multivariate algorithms is different when going from classical accuracy to robustness. Neural networks, which are capable of producing very accurate results with respect to classical RMSEP, are not able to solve interpolation problems or, especially, extrapolation problems. The chemometric methods that are based on the support vector machine (SVM) ideology are capable of solving both classical regression and interpolation/extrapolation tasks.

Analytical sciences in Austria

Analytical chemistry has been an important independent scientific discipline in Austria for many years. This is clearly highlighted by the long existence of dedicated institutes/ departments at Austrian universities (Graz, Linz, Innsbruck and Vienna) providing high-level education as well as engagement in various curricula and research. Furthermore, this is underlined by the existence of an independent Austrian scientific society dedicated to the promotion of analytical sciences, namely the Austrian Society of Analytical Chemistry (ASAC), which was founded in 1948. One of the society’s major aims was to further activities in the area of microchemistry and microanalysis, in which significant progress had been achieved by Fritz Pregl. Pregl was awarded the Nobel Prize in 1923 for his work in microanalysis, work that was carried out at the University of Graz. In the decades following the foundation of ASAC, its focus has shifted from microchemistry to analytical chemistry in a very broad sense, which reflects the huge changes that have taken place in analytical sciences over the years. The title of the journal Microchimica Acta still reminds us of the origins of modern analytical chemistry in Austria. Scientific research in analytical sciences is a privilege of universities, but attitudes towards analytical chemistry as an independent scientific discipline differ from country to country. There is (unfortunately) not full agreement that every chemistry department should have a full professor in analytical chemistry. Universities in Austria have always been aware of the importance of analytical sciences and that experts in this area are vital for progress in chemistry and related fields; therefore, analytical chemistry is well established at Austrian universities. The development of analytical chemistry in Austria and also in the European context has been substantially supported by ASAC. ASAC played a leading role in the Working Party for Analytical Chemistry of the Federation of European Chemical Societies in the 1970s and 1980s (now the Division of Analytical Chemistry of EuCheMS) and it has always been a driving force to make analytical chemistry sufficiently visible for the scientific community. Achievements in Austrian analytical chemistry and of ASAC are internationally recognized. Therefore, it is not surprising that ASAC is continually involved in the organization of international conferences, including meetings dedicated to specific topics in the analytical sciences, as well as broad-ranging conferences such as Euroanalysis (held in Austria in 1990 and in 2009). Looking for hot spots of analytical chemistry in Austria, one should consider the activities of not only universities, but also a range of government laboratories involved in food analysis, environmental analysis, health and related areas. These labs do perform professional routine analytical work, but they are also involved in the validation of new analytical methods in cooperation with international partners. Last but not least, Austria is an attractive location for international chemical and instrument companies that run production plants as well as research facilities, where highly qualified analytical chemists are employed. The idea to prepare a special issue on the progress of analytical sciences in Austria was immediately welcomed Published in the special issue Analytical Sciences in Austria with Guest Editors G. Allmaier, W. Buchberger and K. Francesconi.

Eighth Polish Conference on Analytical Chemistry

The Polish Conference on Analytical Chemistry has a long and rich history. The first such scientific forum took place in Warsaw in 1981. Since 1995, Polish analysts have had a chance to meet every 5 years in Gdansk, Gliwice, Torun, and—in 2010—in Krakow. The VIIIth Polish Conference on Analytical Chemistry was held on July 4–9. It was organized by the Department of Analytical Chemistry, Jagiellonian University, in cooperation with the Polish Committee of Analytical Chemistry of the Polish Academy of Sciences. The meeting attracted 570 participants, who presented their works in the Auditorium Maximum—the main conference center in Krakow. The conference was opened by Adam Hulanicki—a famous and distinguished scientist, and a patron and tutor to several generations of Polish analysts. In his lecture, he recounted the history of Polish analytical conferences, including many interesting and little-known details. Another impressive presentation was given by a special guest of the conference—Georges Guiochon from the University of Tennessee, Knoxville, USA, who is a specialist in chromatographic analysis. He acquainted listeners with the latest developments in this analytical domain, placing emphasis on methodological and instrumental advances. The regular scientific program of the conference encompassed several plenary lectures, as well as oral and poster sessions. Eminent Polish scientists, working mostly in foreign research centers, were invited to deliver the plenary lectures. They were Anna Brajter-Toth (University of Florida, USA), Ewa Cukrowska (University of the Witwatersrand, South Africa), Pawel Ciborowski (University of Nebraska, USA), Tadeusz Gorecki (University of Waterloo, Canada), Andrzej Lewenstam (Abo Akademi University, Finland), Ryszard Łobinski (National Center for Scientific Research, France), and Marek Trojanowicz (Warsaw University, Poland). In their fascinating speeches, they outlined the current state and future directions of different analytical fields, providing a broad overview of the progress in modern analytical chemistry. The oral and poster presentations were given in 12 separate topical sessions, encompassing all the main analytical domains. A unique feature of this conference was a session titled “Criminalistic Analytics” reflecting the strong scientific collaboration between two Cracovian centers: Jagiellonian University and the Institute of Forensic Research. Another session was devoted to the Symposium on Flow Analysis, which has traditionally been organized in Krakow—for the seventh time in 2010. The thematic sessions revealed that Polish analytical chemistry is developing systematically in terms of methodological, instrumental, and applicative aspects, which are being introduced into all branches of our lives. Protection of human health, the environment, and cultural heritage is still of great importance to Polish analysts. Owing to the creation and application of analytical procedures, methods, and instruments of increasing sophistication, it has become possible to identify and determine ever-decreasing amounts of analytes in various forms and of various levels of threat to our environment. Novel techniques for preparation of biological samples together with chromatographic and electrophoretic separation systems and with mass spectrometry as a detection system have opened up new analytical possibilities in clinical, pharmaceutical, and forensic toxicology. The growing interest in exploitation of nondestructive analytical methods, flow techniques, and integrated and miniaturized instrumental systems for different purposes is also worth mentioning. All the above is evidence that analytical chemistry is increasingly being introduced into our everyday lives, helping to make them healthier, safer, and more comfortable. The papers presented in this special issue of Analytical and Bioanalytical Chemistry are representative of the discussion of this tendency at the conference. In addition to the scientific program, there was a wide range of social activities. A Chopin concert, which was held in the courtyard of Wawel Royal Castle, made a great impression on listeners. The conference banquet took place in one of the halls of the Wieliczka Salt Mine, situated within the Krakow metropolitan area—the mining company is believed to be the world's 14th oldest company still in operation today. During the meeting in Zalesie Inn, guests experienced the atmosphere, folklore, and food of the Cracovian region. Finally, all attendees were invited to sightsee Krakow. First on the list was, of course, the Old Town, with the largest mediaeval market square in Europe—the colorful and crowded Main Market with its pigeons and florists and assorted market stalls. Mariacki Church, from the highest tower of which a bugle-call is sounded every hour, and the museum of the famous Jagiellonian University—Alma Mater Cracoviensis—were also visited. The next Polish Conference on Analytical Chemistry will be held in Poznan in 2015.

An Overview of the Generations and Recent Versions of Flow Injection Techniques

The ever increasing demand for rapid, cost-effective, practically-safe, and environmentally-benign analytical methods has aroused researchers to develop automated, miniaturized, versatile, and inexpensive analytical techniques. Flow injection (FI) techniques were well-established to meet the requirements of modern chemical analysis. The family of FI techniques includes three generations, flow injection analysis (FIA), sequential injection analysis (SIA), and bead injection analysis (BIA). In addition, new versions of SIA, micro-SIA-lab-on-valve (μSIA-LOV), and sequential injection chromatography (SIC), have recently been developed for more downscaling analysis and broadening applications. In the literature, we have not found a comprehensive and updated manuscript presenting all generations and recent versions of FI techniques. Therefore, the current manuscript briefly demonstrates the principles, developments, and applications of the FI techniques along with their consequent generations and recent versions.

Characterization of a nose-only inhalation exposure system for hydrocarbon mixtures and jet fuels

A directed-flow nose-only inhalation exposure system was constructed to support development of physiologically based pharmacokinetic (PBPK) models for complex hydrocarbon mixtures, such as jet fuels. Due to the complex nature of the aerosol and vapor-phase hydrocarbon exposures, care was taken to investigate the chamber hydrocarbon stability, vapor and aerosol droplet compositions, and droplet size distribution. Two-generation systems for aerosolizing fuel and hydrocarbons were compared and characterized for use with either jet fuels or a simple mixture of eight hydrocarbons. Total hydrocarbon concentration was monitored via online gas chromatography (GC). Aerosol/vapor (A/V) ratios, and total and individual hydrocarbon concentrations, were determined using adsorbent tubes analyzed by thermal desorption–gas chromatography–mass spectrometry (TDS-GC-MS). Droplet size distribution was assessed via seven-stage cascade impactor. Droplet mass median aerodynamic diameter (MMAD) was between 1 and 3 μm, depending on the generator and mixture utilized. A/V hydrocarbon concentrations ranged from ∼200 to 1300 mg/m3, with between 20% and 80% aerosol content, depending on the mixture. The aerosolized hydrocarbon mixtures remained stable during the 4-h exposure periods, with coefficients of variation (CV) of less than 10% for the total hydrocarbon concentrations. There was greater variability in the measurement of individual hydrocarbons in the A-V phase. In conclusion, modern analytical chemistry instruments allow for improved descriptions of inhalation exposures of rodents to aerosolized fuel.

Food analysis: A continuous challenge for miniaturized separation techniques

One of the current trends of modern analytical chemistry is the miniaturization of the various tools daily used by a large number of researchers. Ultrafast separations, consumption of small amounts of both samples and reagents as well as a high sensitivity and automation are some of the most important goals desired to be achieved. For many years a large number of research laboratories and analytical instrument manufacturing companies have been investing their efforts in this field, which includes miniaturized extraction materials, sample pre-treatment procedures and separation techniques. Among the separation techniques, capillary electromigration methods (which also include CEC), microchip and nano-LC/capillary LC have received special attention. Besides their well-known advantages over other separation tools, the role of these miniaturized techniques in food analysis is still probably in an early stage. In fact, applications in this field carried out by CEC, microchip, nano-LC and capillary LC are only a few when compared with other more established procedures such as conventional GC or HPLC. The scope of this review is to gather and discuss the different applications of such miniaturized techniques in this field. Concerning CE, microchip-CE and CEC works, emphasis has been placed on articles published after January 2007.

Low Pressure Separations Using Automated Flow and Sequential Injection Analysis Coupled to Monolithic Columns

Automation is a key demand in modern analytical chemistry. Automated analytical schemes facilitate samples handling, and enable effective processes such as dilution, extraction, derivatization, and preconcentration to be carried out. Flow (FI) and sequential injection (SI) analysis are well-established and mature automated analytical techniques with more than 18,000 publications so far in all areas of analytical science. FI and SI offer significant advantages such as low instrumental and operational cost, widely available instrumentation, and effective automation of critical steps in the analytical process. Until recently, the main disadvantage of FI and SI was the inability of simultaneous determinations of more than two analytes in a single run. Due to the low pressure operation of these techniques, it was impossible for them to be coupled to conventional particulate-based separation columns that enable chromatographic separations. This drawback was overcome by the introduction of monolithic stationary phases. Monolithic columns are prepared from organic and silica monomers. Silica-based monoliths have small-sized skeletons and a bimodal pore size distribution with microm-sized throughpores and nm-sized mesopores. This gives silica-based monoliths favorable properties for high-efficiency fast separations, such as low-pressure drop across the column, fast mass transfer kinetics and a high binding capacity. They consist of a single rigid porous rod, enabling higher flow rates than particulate columns at reasonable back-pressures. These unique features of monolithic columns enabled their incorporation in low/moderate pressure setups, such as FI and SI, expanding dramatically their possibilities.

Sensors in analytical chemistry

Chemical sensorics is an independent domain of modern analytical chemistry. In Germany and Japan, multivolume encyclopedias dedicated to sensors were published. The publication of the nine-volume encyclopedia [1] in Germany was immediately followed by the appearance of the annual publication [2] incorporating additional data available from US. The preparations to publication of the next encyclopedia of sensors are under way now. It san be said with a good reason that chemical sensorics is a well-established sphere which is still under active development. This is specifically a testing ground for novel ideas and novel materials.

Elimination of undesirable water layers in solid-contact polymeric ion-selective electrodes.

This study aimed to develop a novel approach for the production of analytically robust and miniaturized polymeric ion sensors that are vitally important in modern analytical chemistry (e.g., clinical chemistry using single blood droplets, modern biosensors measuring clouds of ions released from nanoparticle-tagged biomolecules, laboratory-on-a-chip applications, etc.). This research has shown that the use of a water-repellent poly(methyl methacrylate)/poly(decyl methacrylate) (PMMA/PDMA) copolymer as the ion-sensing membrane, along with a hydrophobic poly(3-octylthiophene 2,5-diyl) (POT) solid contact as the ion-to-electron transducer, is an excellent strategy for avoiding the detrimental water layer formed at the buried interface of solid-contact ion-selective electrodes (ISEs). Accordingly, it has been necessary to implement a rigorous surface analysis scheme employing electrochemical impedance spectroscopy (EIS), in situ neutron reflectometry/EIS (NR/EIS), secondary ion mass spectrometry (SIMS), and small-angle neutron scattering (SANS) to probe structurally the solid-contact/membrane interface, so as to identify the conditions that eliminate the undesirable water layer in all solid-state polymeric ion sensors. In this work, we provide the first experimental evidence that the PMMA/PDMA copolymer system is susceptible to water "pooling" at the interface in areas surrounding physical imperfections in the solid contact, with the exposure time for such an event in a PMMA/PDMA copolymer ISE taking nearly 20 times longer than that for a plasticized poly(vinyl chloride) (PVC) ISE, and the simultaneous use of a hydrophobic POT solid contact with a PMMA/PDMA membrane can eliminate totally this water layer problem.

The Impact of Supramolecular Nanocarriers to Contemporary Pharmaceutical and Analytical Chemistry: A Minireview

The paper gives a short review of the most important research results published recently in the field of the applications of supramolecular nanocarriers in modern pharmaceutical and analytical chemistry. The main attention has been paid to the fast developing technology of chemical sensors, ion-selective electrodes and separation methods, in particular to newly designed packing in high-performance liquid chromatography employing supramolecularly aided and membrane mimicking processes.

Modern chemical analysis in archaeometry

All communities, in diverse ways, attempt to preserve their cultural heritage, as it is the main element of their identity within modern civilization. The different directions and ways in which these processes are realized depend on the particular stage of development of science and technology, welfare of society, and encountered dangers of this identity. Very important objects of cultural heritage are material objects and objects of art produced by all communities. The physical and mechanical properties of material culture are always of prime concern to archaeometry and science-based archaeology. The preservation of material culture for future generations with the best possible fidelity requires in-depth knowledge, to aid the most suitable restoration, conservation, storage, and eventual museum display. A wise utilization of modern methods of chemical analysis is a significant element of research studies into such objects providing information on the most suitable methods of their restoration and conservation. There is wide enthusiasm among conservators and curators for the application of analytical tools to enhance the management of collections. Modern chemical analysis offers numerous methods and measuring techniques which can be employed for archaeometric purposes. Advances in their use have already been the subject of several books [1–4], review papers [5–7], and even recent special issues of analytical international journals, e.g., X-Ray Spectrometry in 2000, Journal of Separation Science in 2004, or Microchimica Acta in 2007. From the point of view of application to an investigation of archeological and art objects, it is often important to use both nondestructive (which can be in some cases fully noninvasive) methods as well as destructive methods of modern microanalysis for analysis of small samples. As information about given objects or artistic techniques based only on historical sources may often lead to serious misinterpretations, there are numerous different purposes for the application of chemical analysis in archaeometric studies. They may be extremely valuable in the investigation of the provenance of an object and the origin of the materials used for its manufacture, and in addition in determining its degradation state and monitoring the transformations that happen during the ageing process. They are also useful when choosing the most suitable methods of restoration and conservation, the type of materials for conservation, and also in monitoring the progress of conservation processes. Various analytical methods can also be employed for dating of material objects and identification of fake art objects. Earlier works in this field concentrated mainly on analysis of inorganic materials [1]; however, in the last two decades substantial progress in high-performance separation techniques has allowed detailed determinations of various groups of organic compounds essential for materials studies (dyes, resins, oils, waxes, carbohydrates, and proteins) [8]. Nondestructive methods find a particular place among analytical methods used for archaeometric purposes because of the unique value of most of the objects analyzed. Their principal advantage is the lack of necessity for sampling from objects, and in the case of modern portable instrumentation there is also the possibility of performing measurements on-site. Most commonly these methods are employed for elemental analysis, but in recent decades they have also Anal Bioanal Chem (2008) 391:915–918 DOI 10.1007/s00216-008-2077-x

Understanding the impacts of moisture and thermal ageing on transformer's insulation by dielectric response and molecular weight measurements

Properties of oil and paper in a transformer degrade primarily due to thermal ageing and moisture ingress. Dielectric diagnostic tests, such as Recovery Voltage (RV), and Polarizations and Depolarization Current (PDC) measurement are currently being explored as potential tools for insulation condition assessment. A modern chemical analysis tool for paper molecular weight (MW) measurement, Gel Permeation Chromatography (GPC) or the more accurately described Size Exclusion Chromatography (SEC) promises to be useful in assessing ageing condition. However, the issue of separately assessing the impacts of ageing and moisture on oil and paper has been a key issue for many years. In the current research project, a series of experiments have been performed under controlled laboratory conditions with preset moisture content, and at controlled high temperature ageing. Whereas RV and PDC measurement results were found to be more sensitive to the moisture content of the oil and paper insulation, the MW distribution measurement by SEC provided a trend of insulation thermal ageing. This paper first provides a brief description of RVM, PDC and SEC procedures followed by a description of the experimental techniques adopted. Results are then analysed with the view of separately understanding the impacts of thermal ageing and moisture on the condition of oil and paper insulation in a transformer.