Rapid, repeatable, highly sensitive and semi-quantitative colorimetric detection of elemental sulfur with a colored clathrate

Publication date: 15 November 2019Source: Sensors and Actuators B: Chemical, Volume 299Author(s): Peng Yu, Yuanming Zhai, Rui-Ying Bao, Zheng-Ying Liu, Ming-Bo Yang, Wei YangAbstractIn chemical industry, elemental sulfur (S) is widely used and always causes environmental and pollution concerns. Hence, the rapid and simple detection of S has become an important issue. In this work, we report an effective approach for visible determination of S. The color of the detection reagent, which was readily prepared by mixing N, N-Dimethylformamide and hydrazine hydrate in a certain ratio, changes from colorless to blue and gradually fades after getting in contact with trace S. The detection reagent can be used for repeated S detection because of the color fading behavior. By measuring the characteristic absorption intensity during detection or the fading time of the mixture, the content of S in the sample can be readily determined and the detection limit can be as low as 0.32 mg/L. An unstable chromogenic organic clathrate generated during detection was found to be responsible for the chromogenic reaction, as revealed by UV–vis, FTIR, NMR, high resolution mass spectrometry measurements and simulation. Thus, this work presents a simple, fast and device-independent approach that can realize semi-quantitative detection of trace S in water, alcohol, food and environmental samples.Graphical abstract
Source: Sensors and Actuators B: Chemical - Category: Chemistry Source Type: research