Jacek Namieśnik

PAH diagnostic ratios for the identification of pollution emission sources.

Polycyclic aromatic hydrocarbon (PAH) diagnostic ratios have recently come into common use as a tool for identifying and assessing pollution emission sources. Some diagnostic ratios are based on parent PAHs, others on the proportions of alkyl-substituted to non-substituted molecules. The ratios are applicable to PAHs determined in different environmental media: air (gas + particle phase), water, sediment, soil, as well as biomonitor organisms such as leaves or coniferous needles, and mussels. These ratios distinguish PAH pollution originating from petroleum products, petroleum combustion and biomass or coal burning. The compounds involved in each ratio have the same molar mass, so it is assumed they have similar physicochemical properties. Numerous studies show that diagnostic ratios change in value to different extents during phase transfers and environmental degradation. The paper reviews applications of diagnostic ratios, comments on their use and specifies their limitations.

Estimating uncertainty in analytical procedures based on chromatographic techniques.

Chromatographic techniques are very frequently used in analytical procedures for the separation, determination and identification of a wide spectrum of analytes present in samples with complex and sometimes variable matrices. However, the estimation of uncertainty of the final results does not include the uncertainties associated with the actual chromatographic process. In effect, such results cannot always be treated as a reliable source of analytical information. In this paper we present the basic terms, sources of uncertainty, and methods of calculating the combined uncertainty that any presentation of final determinations should include.

Green aspects, developments and perspectives of liquid phase microextraction techniques

Determination of analytes at trace levels in complex samples (e.g. biological or contaminated water or soils) are often required for the environmental assessment and monitoring as well as for scientific research in the field of environmental pollution. A limited number of analytical techniques are sensitive enough for the direct determination of trace components in samples and, because of that, a preliminary step of the analyte isolation/enrichment prior to analysis is required in many cases. In this work the newest trends and innovations in liquid phase microextraction, like: single-drop microextraction (SDME), hollow fiber liquid-phase microextraction (HF-LPME), and dispersive liquid-liquid microextraction (DLLME) have been discussed, including their critical evaluation and possible application in analytical practice. The described modifications of extraction techniques deal with system miniaturization and/or automation, the use of ultrasound and physical agitation, and electrochemical methods. Particular attention was given to pro-ecological aspects therefore the possible use of novel, non-toxic extracting agents, inter alia, ionic liquids, coacervates, surfactant solutions and reverse micelles in the liquid phase microextraction techniques has been evaluated in depth. Also, new methodological solutions and the related instruments and devices for the efficient liquid phase micoextraction of analytes, which have found application at the stage of procedure prior to chromatographic determination, are presented.

Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry.

Solid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about novel methodological and instrumental solutions in relation to different variants of solid phase extraction techniques, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE) and magnetic solid phase extraction (MSPE) is presented, including practical applications of these techniques and a critical discussion about their advantages and disadvantages. The proposed solutions fulfill the requirements resulting from the concept of sustainable development, and specifically from the implementation of green chemistry principles in analytical laboratories. Therefore, particular attention was paid to the description of possible uses of novel, selective stationary phases in extraction techniques, inter alia, polymeric ionic liquids, carbon nanotubes, and silica- and carbon-based sorbents. The methodological solutions, together with properly matched sampling devices for collecting analytes from samples with varying matrix composition, enable us to reduce the number of errors during the sample preparation prior to chromatographic analysis as well as to limit the negative impact of this analytical step on the natural environment and the health of laboratory employees.

Accelerated Solvent Extraction (ASE) in the Analysis of Environmental Solid Samples — Some Aspects of Theory and Practice

Theoretical basis, equipment, and some practical considerations regarding the use of a new extraction technique, Accelerated Solvent Extraction (ASE), are presented. ASE is quite a new technique, but its use has so far been limited due to its high cost. This review attempts to summarize some aspects of the theory, results, and conclusions of research related to ASE found in the literature. Applications of this technique to the extraction of various environmental pollutants from solid samples are presented. Finally, the comparisons of ASE to other extraction techniques and its advantages and disadvantages are discussed. Classic techniques of analyte isolation from solid samples (such as Soxhlet extraction, flask extraction) are tedious and time-consuming, which lowers the sample throughput. Accelerated Solvent Extraction is a fully automated technique, so it could be especially useful for routine analyses of environmental pollutants and food.

Passive sampling for long-term monitoring of organic pollutants in water

Abstract Commonly used monitoring systems usually record only pollutant concentrations at a specific point in time. Passive dosimetry, widely used to monitor air pollutants, can also be applied to monitor organic contaminants in water. Contrary to dynamic techniques, passive sampling is less sensitive to accidental extreme variations of the organic pollutant concentration in natural waters. A passive sampler can cover a long sampling period, integrating the pollutant concentration over time. Since only a few analyses are necessary over the monitoring period, analytical costs (usually connected with expensive dynamic sample isolation and preconcentration techniques) can be reduced substantially. Moreover, decomposition of the sample during transport and storage and/or changes during sample enrichment are also minimised. In this review, the present state of the art of passive water sampling for long-term monitoring of organic pollutants in water is discussed.

Ionic Liquids and Deep Eutectic Mixtures: Sustainable Solvents for Extraction Processes

In recent years, ionic liquids and deep eutectic mixtures have demonstrated great potential in extraction processes relevant to several scientific and technological activities. This review focuses on the applicability of these sustainable solvents in a variety of extraction techniques, including but not limited to liquid- and solid-phase (micro) extraction, microwave-assisted extraction, ultrasound-assisted extraction and pressurized liquid extraction. Selected applications of ionic liquids and deep eutectic mixtures on analytical method development, removal of environmental pollutants, selective isolation, and recovery of target compounds, purification of fuels, and azeotrope breaking are described and discussed.

Food Analysis Using Artificial Senses

Nowadays, consumers are paying great attention to the characteristics of food such as smell, taste, and appearance. This motivates scientists to imitate human senses using devices known as electronic senses. These include electronic noses, electronic tongues, and computer vision. Thanks to the utilization of various sensors and methods of signal analysis, artificial senses are widely applied in food analysis for process monitoring and determining the quality and authenticity of foods. This paper summarizes achievements in the field of artificial senses. It includes a brief history of these systems, descriptions of most commonly used sensors (conductometric, potentiometric, amperometic/voltammetric, impedimetric, colorimetric, piezoelectric), data analysis methods (for example, artificial neural network (ANN), principal component analysis (PCA), model CIE L*a*b*), and application of artificial senses to food analysis, in particular quality control, authenticity and falsification assessment, and monitoring of production processes.

Understanding solid-phase microextraction: key factors influencing the extraction process and trends in improving the technique.

Analytical chemists are faced with the daunting challenges of accurately monitoring the state of the environment and the processes taking place in it and of determining an enormous range of analytes often present in trace and ultratrace amounts in sample matrixes with complex or variable compositions. Further challenges are presented by the need to introduce new methodologies into current analytical practice and equipment to comply with the principles of sustainable development and green chemistry. Highest among these principles is the elimination or at least the substantial reduction of the quantities of reagents consumed (especially organic solvents and toxic compounds), solid and liquid wastes produced, and vapors and gases emitted. In analytical chemistry these principles are implemented above all by the utilization of ever more sensitive and automated instruments and of monitoring equipment which allows many analytes to be determined in a single analytical run, by the wide application of direct analytical techniques, operating in situ, and by the introduction of additional isolation and/or preconcentration steps prior to the final determination.

Determination of volatile aliphatic amines in air by solid-phase microextraction coupled with gas chromatography with flame ionization detection.

Practical aspects of the application of solid-phase microextraction (SPME) to the determination of volatile aliphatic amines in air are described. Analytes included methylamine (MA), ethylamine (EA), dimethylamine (DMA), diethylamine (DEA), trimethylamine (TMA) and triethylamine (TEA). New SPME stationary phases were examined. The effects of relative humidity and temperature on analytes uptake were taken into account in analysis. Gas chromatography (GC) with flame ionization detector (FID) was used for the final analysis.