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Microextraction techniques have been proven to provide similar or better results in terms of sensitivity and reproducibility in comparison to liquid-liquid extraction (LLE) and solid-phase extraction (SPE). Furthermore, the high time efficiency and decreased workload leads to a higher sample throughput. In this review the state of the art of some of these techniques, namely solidphase microextraction (SPME), stir-bar sorptive extraction (SBSE), solid-phase dynamic extraction (SPDE), in-tube extraction-dynamic headspace (ITEX-DHS) and PAL SPME Arrow is shown. Furthermore, their benefits and drawbacks are discussed, together with their applicability to the analysis of water samples. To that end, the latest publications of microextraction techniques for a selection of regulated compound classes (chlorophenols (CPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, shortchained chlorinated paraffins (SCCPs) and volatile organic compounds (VOCs)) are compared.Finally, a guideline for choosing the best microextraction technique for different analytical needs is described.

Oxidative processes frequently contribute to organic pollutant degradation in natural and engineered systems such as during the remediation of contaminated sites and in water treatment processes. Because a systematic characterization of abiotic reactions of organic pollutants with oxidants such as ozonation or hydroxyl radicals by compound-specific stable isotope analysis (CSIA) is lacking, stable isotope-based approaches have rarely been applied for the elucidation of mechanisms of such transformations. Here, we investigated the carbon isotope fractionation associated with the oxidation of benzene and several methylated and methoxylated analogs, namely toluene, three xylene isomers, mesitylene and anisole, and determined their carbon isotope enrichments factors (εC) for reactions with ozone (εC = −3.6 ‰ to −4.6 ‰) and hydroxyl radicals (εC = 0.0 to −1.2 ‰). The differences in isotope fractionation can be used to elucidate the contribution of the reactions with ozone or hydroxyl radicals to overall transformation. Derivation of apparent kinetic isotope effects (AKIEs) for the reaction with ozone, however, was nontrivial due to challenges in assigning reactive positions in the probe compounds for the monodentate attack leading to an ozone adduct. We present several options for this step and compare the outcome to quantum chemical characterizations of ozone adducts.Our data show that a general assignment of reactive positions for reactions of ozone with aromatic carbon in ortho-, metaor para-positions is not feasible and that AKIEs of this reaction should be derived on a compound-by-compound basis.

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Bismuth (III) sulfide has been widely researched in recent years due to its application, but little emphasis has been placed on research regarding its behavior at elevated temperatures. This is of great importance, considering that bismuth, in the form of Bi2S3, is found in copper sulfide concentrates and is considered one of the most harmful components, along with lead, arsenic and antimony. The removal of these substances is one of the basic tasks in the processes of pyrometallurgical extraction of copper, in order to obtain a high purity metal. In order to better understand the behavior of bismuth (III) sulfide during oxidation at elevated temperatures, this paper characterized the synthesized sample of Bi2S3 at room temperature and the oxidation products at 500 °C by X-Ray diffraction (XRD), as well as thermodynamic, thermal and kinetic analysis of the oxidation process of Bi2S3 at elevated temperatures. In order to understand the behavior of Bi2S3 during oxidation and the distribution of oxidation products, phase stability diagrams in the Bi-S-O system were constructed at different temperatures and the values of the Gibbs free energy change at 400 °C and 1000 °C were calculated. Kinetic analysis of Bi2S3 oxidation process was performed by Kissingers method in non-isothermal conditions.