Saar Indrek, Evard Hanno
Chair of Analytical Chemistry, Institute of Chemistry, University of Tartu, Ravila 14a, 50411Tartu, Estonia.
ACS Omega. 2025 Jan 6;10(1):1800-1808. doi: 10.1021/acsomega.4c10152. eCollection 2025 Jan 14.
Water is an essential part of everyday life, and similarly, numerous industries depend on it. Regular water analysis is needed for both home use and in more specific fields, e.g., in agriculture, to ensure necessary quality. For an inexpensive and more convenient alternative to laboratory analysis, reliable and easy-to-use on-spot analysis devices are required. In this study, a novel particle-based microfluidic test for the quantitative analysis of iron and copper ions was developed. This is the first time that particle-based microfluidics has been demonstrated in a self-contained test to analyze real-world samples. The working range for both analytes was from 0.05 to 5 ppm with detection limits of 38 ppb for copper and 10 ppb for iron. This was achieved through a novel approach with sequentially placed immobile colorimetric reagents that can concentrate the analytes from the sample. In addition to the excellent suitability of monitoring drinking water, the applicability of the test to samples containing chelating agents was demonstrated. Different tap water samples and nutrient solutions from a hydroponic farm were used to successfully cross-validate tests' performance with accredited laboratory methods. To the authors' knowledge, such on-spot tests for complex samples containing strong chelating agents have not been successfully demonstrated before. Overall, the tests required under a minute of hands-on time, and no expertise is needed to perform the analysis. An ordinary portable flatbed scanner was used for quantification, allowing the entire analysis to be performed on the spot.
水是日常生活的重要组成部分，同样，许多行业也依赖于水。家庭用水以及更特定的领域，如农业，都需要定期进行水质分析，以确保必要的水质。为了获得一种比实验室分析更便宜、更方便的替代方法，需要可靠且易于使用的现场分析设备。在本研究中，开发了一种基于颗粒的微流控测试方法，用于定量分析铁离子和铜离子。这是首次在独立测试中展示基于颗粒的微流控技术用于分析实际样品。两种分析物的工作范围均为0.05至5 ppm，铜的检测限为38 ppb，铁的检测限为10 ppb。这是通过一种新颖的方法实现的，即依次放置固定的比色试剂，可从样品中富集分析物。除了非常适合监测饮用水外，还证明了该测试对含有螯合剂的样品的适用性。使用不同的自来水样品和水培农场的营养液，通过认可的实验室方法成功交叉验证了测试性能。据作者所知，此前尚未成功展示过针对含有强螯合剂的复杂样品的此类现场测试。总体而言，该测试只需不到一分钟的实际操作时间，且进行分析无需专业知识。使用普通的便携式平板扫描仪进行定量，可在现场完成整个分析。
