Analytical and Food Chemistry Department, Faculty of Chemistry, Marine Research Center (CIM), University of Vigo, Campus As Lagoas-Marcosende s/n, Vigo, 36310, Spain.
J Sep Sci. 2020 May;43(9-10):1908-1914. doi: 10.1002/jssc.201901339. Epub 2020 Mar 11.
The use of paper-based devices in combination with noninstrumental detection systems is becoming increasingly important in the analytical field due to its simplicity, rapidity, and low cost. However, their use for determination of volatile analyte derivatives is still relatively scarce. The present work reports on the assessment of a paper-based gas-sensing approach for the simultaneous noninstrumental colorimetric detection of nitrite and sulfide. Colorimetric systems based on the Griess and methylene blue assays, formation of colored metallic sulfides, and interaction/reaction with in situ generated metallic nanoparticles were preliminary evaluated. Then, the effect of experimental variables affecting the analytical performance of the paper-based gas sensor was studied with two digitization systems, namely a scanner and a smartphone. Under optimal conditions, the developed system yielded limits of detection of 0.055 and 0.005 mg/L for nitrite and sulfide, respectively. The repeatability, expressed as relative standard deviation, was found to be 5.9 and 6.7% for nitrite and sulfide, respectively. The proposed method was finally applied to the analysis of water samples, showing recoveries in the range of 95-105%.
由于其简单、快速和低成本，基于纸的设备与非仪器检测系统结合在分析领域的应用变得越来越重要。然而，它们在挥发性分析物衍生物的测定中的应用仍然相对较少。本工作报道了一种基于纸的气体传感方法的评估，用于同时进行非仪器比色检测亚硝酸盐和硫化物。基于格里厄斯和亚甲基蓝测定法、有色金属硫化物的形成以及与原位生成的金属纳米粒子的相互作用/反应的比色系统进行了初步评估。然后，使用两种数字化系统（扫描仪和智能手机）研究了影响基于纸的气体传感器分析性能的实验变量的影响。在最佳条件下，开发的系统对亚硝酸盐和硫化物的检出限分别为 0.055 和 0.005 mg/L。亚硝酸盐和硫化物的重复性（表示为相对标准偏差）分别为 5.9%和 6.7%。该方法最后应用于水样分析，回收率在 95-105%范围内。
