The interaction between a cold gas plasma and water creates a plasma activated liquid, a solution rich in highly reactive chemical species. Such liquids have garnered considerable attention due to their powerful antimicrobial properties and ease of production. In this contribution, air plasma was used to activate potable water samples from five different countries, including the UK, France, Norway, Slovenia and Palestine. All water samples had an initial pH in the range of 7.9 to 8.2, following plasma activation samples from the UK and Norway reached a pH below 3, whereas water from France and Palestine remained stable at 8. The concentration of NO₃⁻ increased in all samples, reaching a maximum concentration of 3 mM after 25 min plasma exposure; whereas the concentration of NO₂⁻ showed a non-linear dependence with exposure time, reaching between 10 and 25 µM after 25 min of exposure. To demonstrate the impact of water origin on the antimicrobial potential of each solution, the inactivation of Staphylococcus aureus and Escherichia coli was considered. It was found that activated water from the UK was capable of achieving > 6 log reduction, whereas water from Palestine was only able to achieve a 0.4 log reduction, despite both liquids receiving an identical plasma exposure. The study demonstrates the importance of initial water composition on the level of plasma activation, indicating that additional purification steps prior to activation may be necessary to ensure efficacy and repeatability.

冷气体等离子体和水之间的相互作用产生等离子体活化液体，这是一种富含高活性化学物质的溶液。由于其强大的抗菌性能和易于生产，此类液体已经引起了相当大的关注。在这项贡献中，空气等离子体用于激活来自五个不同国家的饮用水样品，包括英国、法国、挪威、斯洛文尼亚和巴勒斯坦。所有水样的初始 pH 值范围为 7.9 至 8.2，在来自英国和挪威的血浆活化样品达到低于 3 的 pH 值，而来自法国和巴勒斯坦的水样保持稳定在 8。NO ₃ ^-的浓度在所有样品，在血浆暴露 25 分钟后达到 3 mM 的最大浓度；而 NO ₂的浓度^-显示出与曝光时间的非线性相关性，在曝光 25 分钟后达到 10 到 25 µM。为了证明水源对每种溶液的抗菌潜力的影响，考虑了金黄色葡萄球菌和大肠杆菌的灭活。发现来自英国的活化水能够实现 > 6 log 减少，而来自巴勒斯坦的水只能实现 0.4 log 减少，尽管两种液体接受相同的血浆暴露。该研究证明了初始水组成对等离子体活化水平的重要性，表明可能需要在活化之前进行额外的纯化步骤以确保功效和可重复性。