During the Folin Ciocalteu (F-C) micro-assay for the determination of phenolics in the presence of methanol, fine solids can form. In a previous paper, we hypothesized that the interference from alcohol on the F-C rea...During the Folin Ciocalteu (F-C) micro-assay for the determination of phenolics in the presence of methanol, fine solids can form. In a previous paper, we hypothesized that the interference from alcohol on the F-C reaction can be minimized depending on the particular procedure used to reach the alkalinity condition. In order to demonstrate our hypothesis we studied, by spectrophotometrically monitoring, the time-behaviour of the reactions carried out in the presence of different methanol concentrations at the same alkalinity condition from two protocols. The results showed that the interfering effect of methanol on the F-C micro-method can be affect and even prevented depending on working conditions. In particular, the formation of fine solids can be delayed, slowed down and prevented depending on the initial carbonate concentration used. We have explained why the initial carbonate concentration, used to reach the final alkalinity condition, plays an important role in the F-C reaction carried out in the presence of methanol. Moreover, the results from real-time monitoring showed that, differently from traditional F-C procedure, our procedure allows us to carry out the F-C micro method in the presence of 6% methanol, as an extreme concentration, reading the absorbance at real time 24 min. The real-time monitoring of absorbance can be considered as a useful means to explore the effect of other parameters on precipitate formation caused by the presence of methanol in the F-C reaction.展开更多
为探究海洋环境中微/纳塑料定量的研究现状、热点和未来发展趋势,研究基于Web of Science核心数据库,利用CiteSpace对2012—2023年海洋环境中微/纳塑料定量研究领域的422篇相关文献进行可视化分析。研究从年发文量、研究机构、国家及作...为探究海洋环境中微/纳塑料定量的研究现状、热点和未来发展趋势,研究基于Web of Science核心数据库,利用CiteSpace对2012—2023年海洋环境中微/纳塑料定量研究领域的422篇相关文献进行可视化分析。研究从年发文量、研究机构、国家及作者合作网络、关键词聚类及突现、共被引分析等多个角度展开。结果显示:海洋环境中微/纳塑料表征领域发文量总体呈上升趋势,目前处于研究波动发展阶段。在该领域中,我国的发文数量居首,但与其他国家的合作仍需加强;意大利则以较高的发文量和紧密的国际合作展现出良好的发展态势。需要指出的是,国外机构间的合作更加密切,且核心作者群和高被引文献大多来自国外。关键词聚类分析表明,研究主要集中在微/纳塑料的赋存特征、表征与定量、生态风险三方面。关键词突现分析表明,微/纳塑料源-汇过程的数值模拟与预测、纳米尺寸塑料的表征与定量,以及从样品采集到检测方法的统一与标准化,将成为该研究领域未来的重要发展方向和热点。展开更多
文摘During the Folin Ciocalteu (F-C) micro-assay for the determination of phenolics in the presence of methanol, fine solids can form. In a previous paper, we hypothesized that the interference from alcohol on the F-C reaction can be minimized depending on the particular procedure used to reach the alkalinity condition. In order to demonstrate our hypothesis we studied, by spectrophotometrically monitoring, the time-behaviour of the reactions carried out in the presence of different methanol concentrations at the same alkalinity condition from two protocols. The results showed that the interfering effect of methanol on the F-C micro-method can be affect and even prevented depending on working conditions. In particular, the formation of fine solids can be delayed, slowed down and prevented depending on the initial carbonate concentration used. We have explained why the initial carbonate concentration, used to reach the final alkalinity condition, plays an important role in the F-C reaction carried out in the presence of methanol. Moreover, the results from real-time monitoring showed that, differently from traditional F-C procedure, our procedure allows us to carry out the F-C micro method in the presence of 6% methanol, as an extreme concentration, reading the absorbance at real time 24 min. The real-time monitoring of absorbance can be considered as a useful means to explore the effect of other parameters on precipitate formation caused by the presence of methanol in the F-C reaction.
文摘为探究海洋环境中微/纳塑料定量的研究现状、热点和未来发展趋势,研究基于Web of Science核心数据库,利用CiteSpace对2012—2023年海洋环境中微/纳塑料定量研究领域的422篇相关文献进行可视化分析。研究从年发文量、研究机构、国家及作者合作网络、关键词聚类及突现、共被引分析等多个角度展开。结果显示:海洋环境中微/纳塑料表征领域发文量总体呈上升趋势,目前处于研究波动发展阶段。在该领域中,我国的发文数量居首,但与其他国家的合作仍需加强;意大利则以较高的发文量和紧密的国际合作展现出良好的发展态势。需要指出的是,国外机构间的合作更加密切,且核心作者群和高被引文献大多来自国外。关键词聚类分析表明,研究主要集中在微/纳塑料的赋存特征、表征与定量、生态风险三方面。关键词突现分析表明,微/纳塑料源-汇过程的数值模拟与预测、纳米尺寸塑料的表征与定量,以及从样品采集到检测方法的统一与标准化,将成为该研究领域未来的重要发展方向和热点。
