Daniel Dziedzic

The preparation of samples for instrumental analysis is the most essential and time-consuming stage of the entire analytical process; it also has the greatest impact on the analysis results. Concentrating the sample, changing its matrix, and removing interferents are often necessary. Techniques for preparing samples for analysis are constantly being developed and modified to meet new challenges, facilitate work, and enable the determination of analytes in the most comprehensive concentration range possible. This paper focuses on using metal-organic frameworks (MOFs) as sorbents in the most popular techniques for preparing liquid samples for analysis, based on liquid-solid extraction. An increase in interest in MOFs-type materials has been observed for about 20 years, mainly due to their sorption properties, resulting, among others, from the high specific surface area, tunable pore size, and the theoretically wide possibility of their modification. This paper presents certain advantages and disadvantages of the most popular sample preparation techniques based on liquid-solid extraction, the newest trends in the application of MOFs as sorbents in those techniques, and, most importantly, presents the reader with a summary, which a specific technique and MOF for the desired application. To make a tailor-made and well-informed choice as to the extraction technique.

This article presents the results of investigations of the morphology and structure of carbon deposit formed as a result of ethanol decomposition at 500 °C, 600 °C, and 700 °C without water vapour and with water vapour (0.35 and 1.1% by volume). scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) observations as well as energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD), and Raman spectroscopic analyses allowed for a comprehensive characterization of the morphology and structure of cylindrical carbon nanostructures present on the surface of the Ni₃Al catalyst. Depending on the reaction mixture composition (i.e., water vapour content) and decomposition temperature, various carbon nanotubes/carbon nanofibres (CNTs/CNFs) were observed: multiwalled carbon nanotubes, herringbone-type multiwall carbon nanotubes, cylindrical carbon nanofibers, platelet carbon nanofibers, and helical carbon nanotubes/nanofibres. The discussed carbon nanostructures exhibited nickel nanoparticles at the ends and in the middle part of the carbon nanostructures as catalytically active centres for efficient ethanol decomposition.

Large amounts of ammunition were dumped in seas and oceans after World War II. After more than 70 years, these munitions still pose a threat to marine environments and humans. In this study, methods used for the analysis of 2,4,6-trinitrotoluene (TNT) and its degradation products from environmental samples were successfully developed, validated and compared. Three sample preparation techniques were selected: solid–liquid extraction, accelerated solvent extraction and Soxhlet extraction. Due to the short process time and lack of need to use complicated equipment, the method recommend for the analysis of explosives in bottom sediments is solid–liquid extraction. The detection (LOD) and quantification (LOQ) limits of TNT and its degradation products determined with GC-MS/MS range from 0.3 ng mL⁻¹ to 173.4 ng mL⁻¹. 4-Nitrotoluene is characterized by the lowest LOQ and LOD, respectively, of 0.9 ng mL⁻¹ and 0.3 ng mL⁻¹. The analyte recoveries of all compounds ranged from 64.6% to 91.8%, with good accuracies (from 96.7% to 103.1%) and good precision, expressed as the coefficient of variation (CV, from 2.1% to 6.4%).