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Cork stoppers are the preferred choice for sealing bottled wines around the world. However, the quality of cork stoppers is also defined by the presence of 2,4,6-trichloroanisole (TCA), which gives the wine an unpleasant moldy/musty taste. It is a matter of concern for both cork stopper manufacturers and wine producers whether TCA can be transported between stoppers. As little is known about cross contamination between stoppers, this work provides enough experimental data to discuss the extent of TCA transfer in naturally contaminated stoppers in the liquid and gas phase that can be useful to the cork industry and the wine industry. We found that when a clean stopper is soaked together with a contaminated one in hydro-alcoholic solution, 12% of the TCA can be transferred. In gas-phase contamination, only stoppers with 12 ng/L, or more, contaminate clean stoppers when enclosed together for several days. In a second experiment, where clean corks were exposed to a controlled contaminated environment, it was found that TCA contamination was not confined to the outermost layer of the stoppers. Based on these findings, some recommendations are given to prevent TCA cross contamination between stoppers during the cork stopper manufacturing, storage, wine making, and bottling.

Funding Information: This work has received funding from the EMPIR programme (projects 16NRM05 and 20SIP01) co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation programme and the Portuguese National Funding Agency for Science, Research and Technology in the framework of the project UIDB/FIS/ 00068/2020. Publisher Copyright: © 2023 The Author(s) Recently, a new type of ionization vacuum gauge was introduced, which was proposed as a reference and transfer standard in the range of 10-6 Pa to 10-2 Pa because of its excellent stability and linearity. In contrast to present models of ionisation vacuum gauges, all electrons have a well-defined path length through the ionisation space. This even allows one to predict the sensitivity for a gas species provided that the ionisation cross section of the gas molecules for electrons between 50 eV and 200 eV is known. Following the development of this gauge we investigated its metrological performance in terms of linearity, resolution, repeatability, reproducibility, transport and long-term stability, disturbances by magnetic fields, influence of the surrounding earth potential and so on. The gauge demonstrated excellent metrological properties and is indeed suitable as an accurate reference and transfer standard, but can also provide important economic benefits to manufacturers and users. publishersversion published

Funding Information: The support of the Portuguese Foundation for Science and Technology via the grants UIDB/00068/2020 and UIDP/00068/2020 is gratefully acknowledged. One of the authors (R. Silva) would like also to express his gratitude to the Portuguese Foundation for Science and Technology for his scholarship UI/BD/150626/2020. Publisher Copyright: © 2022 Elsevier Ltd Hot cathode ionisation gauges are the only reliable pressure measurement devices suitable for both high and ultra-high vacuum measurement. These devices are characterized by low accuracy that is hardly better than 20%. The sources of loss of accuracy are documented in the literature although their quantification and details are not fully understood. In the present work, simulations of Bayard-Alpert and extractor gauges were performed under the influence of uniform magnetic fields up to 30 Gs. Results are in qualitative agreement with measurements taken previously with the Bayard-Alpert gauge. Both gauges are sensitive to low intensity magnetic fields which may be present in vacuum chambers. However, the extractor gauge proved to be more stable in the presence of a magnetic field due to its ring-shaped cathode. publishersversion published