oil-mature Barnett Shale of the Fort Worth Basin (USA). DMextracted less polar and smaller NSO compounds in comparison with ACM, in line with its relatively low polarity. N , N O and O compounds are the 1 1 1 2 dominating species in the DMextracts, whereas the likely more polar compounds such as the N , N O and 2 1 2 N O species are almost un-extracted using DM. Even for the N , N O and O species, their high DBE (double 2 1 1 1 1 2 bond equivalent) classes were neither efficiently extracted using DM. Because NSO compounds are fractionated during both primary and secondary migration, and geochemical indices have been developed to address the magnitude of these processes, it is vital that relevant chemical species are recovered from the shale efficiently. The inefficient extraction of DMmakes the previous investigations of NSO compounds apparently doubtful. ACM has proved to be by far a better solvent, not only because of its high polarity but also because it is likely to gain access to the components trapped in kerogen by bringing about swelling. The azeotropic solvent mixture ACM is recommended for extracting oil-mature shale for future FT-ICR-MS analysis.

Hand, E., 2020. Cheap shots. Science 367, 354-358.

http://science.sciencemag.org/content/367/6476/354.abstract Cryo-EM reveals exquisite molecular structures - at high cost. A cheaper microscope could bring the resolution revolution to the masses.

Hansen, F.A., Pedersen-Bjergaard, S., 2020. Emerging extraction strategies in analytical chemistry. Analytical Chemistry 92, 2-15.

https://doi.org/10.1021/acs.analchem.9b04677 Extraction in the context of analytical chemistry (analytical- scale extraction) is defined as 'the transfer of target analyte from one phase to a different phase where further processing and analysis occurs'. (1) The target analyte is thus isolated from the original sample, and transferred into an extract. In this way, the target analyte is separated from major sample matrix components. The sample is often a liquid, and the target analyte is extracted into (a) another liquid or (b) onto a solid. Extraction according to (a) and (b) are termed liquid - liquid extraction (LLE) and solid-phase extraction (SPE), respectively, and involve partition and mass transfer across liquid - liquid and liquid - solid boundaries. Partition is based on intermolecular forces involving hydrophobic, dispersion, dipole, hydrogen bond, and ionic interactions. The molecular interactions are highly influenced by the chemical properties of the extraction phase (extraction chemistry). In this review, we discuss new extraction phases, which are currently investigated in the scientific literature. In addition, we discuss new technical formats (geometries) for extraction. Emerging extraction strategies, as stated in the review title, are thus defined as new extraction phases and new technical formats in this review. Measurements in analytical chemistry are performed with analytical instruments based on chromatography, electrophoresis, spectroscopy/spectrometry, and electrochemistry. Prior to such measurements, sample preparation is required, and this typically involves extraction. Extraction improves the compatibility of the sample with the analytical instrument. Extraction also cleans up samples and reduces interferences and contamination of the analytical instrument. Finally, extraction may preconcentrate the analyte to lower the limit of detection/quantification. While development of analytical instruments has been a very active field of research for decades, sample preparation and analytical-scale extraction is less developed. Even today, sample preparation is often performed with old LLE and SPE procedures. Fortunately, research on new extraction strategies has increased during the last 2 decades. Solid-phase microextraction (SPME),(2) stir bar sorptive extraction (SBSE),(3) and microextraction by packed sorbent (MEPS)(4) are examples of new techniques derived from this research. They are different miniaturized formats for solid-phase extraction and are commercially available. Thus, SPME, SBSE, and MEPS equipment is standardized and produced industrially, and the techniques are gradually being implemented into routine applications. In parallel to this, new extraction strategies are under development. Largely, this research is conducted in university laboratories, and the scientific papers are focused on proof-of- principle experiments.