BACKGROUND Elemental sulfur (S) persists in natural aquatic environment in a variety of forms with different size distributions from dissolved to particulate. Determination of S speciation mainly consists of the application of chromatographic and electrochemical techniques while its size determination is limited only to the application of microscopic and light scattering techniques. S biological and geochemical importance together with recent increases of S industrial applications requires the development of different analytical tools for S sizing and quantification. In recent years the use of electrochemical measurements as a direct, fast, and inexpensive technique for the different nanoparticles (NPs) characterization (Ag, Au, Pt) is increasing. In this work, electrochemical i.e. chronoamperometric measurements at the Hg electrode are performed for determination of the size distribution of the S NPs. RESULTS S NPs were synthesized in aqueous medium by sodium polysulphide acidic hydrolysis. Chronoamperometric measurements reveal the polydisperse nature of the formed suspension of S NPs. The electrochemical results were compared with dynamic light scattering measurements parallel run in the same S NPs suspensions. The two methods show fairly good agreement, both suggesting a log-normal size distribution of the S NPs sizes characterized by similar parameters. CONCLUSIONS The preliminary results highlight the amperometric measurements as a promising tool for the size determination of the S NPs in the water environment.

中文翻译：

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氯化钠水溶液中元素硫 (S) 纳米颗粒 (NP) 的计时电流研究：S 纳米颗粒分级和检测的新方法。


背景技术元素硫(S)以多种形式存在于天然水生环境中，具有从溶解到颗粒的不同尺寸分布。 S形态的测定主要包括应用色谱和电化学技术，而其尺寸测定仅限于应用显微和光散射技术。 S 的生物和地球化学重要性以及最近 S 工业应用的增加需要开发不同的分析工具来进行 S 测定和定量。近年来，越来越多地使用电化学测量作为一种直接、快速且廉价的技术来表征不同的纳米颗粒 (NP)（Ag、Au、Pt）。在这项工作中，在 Hg 电极上进行电化学测量，即计时电流测量，以确定 S NP 的尺寸分布。结果在水介质中通过多硫化钠酸性水解合成了S NPs。计时电流测量揭示了所形成的 S NP 悬浮液的多分散性质。将电化学结果与在相同 S NP 悬浮液中平行运行的动态光散射测量结果进行比较。这两种方法表现出相当好的一致性，都表明 S NP 尺寸的对数正态尺寸分布具有相似的参数。结论 初步结果强调电流测量法是确定水环境中 S NP 尺寸的有前途的工具。