Identification and application of Cr(VI) based on 2-amino-5-substituted-1,3,4-thiadiazole molecular probes

Abstract

With the modernization of industry, increasingly serious water pollution has become a global environmental pollution problem. Cr (Ⅵ) is the most common water pollutant and is applied to aluminum plating, paint production leather tanning, etc. Cr (Ⅵ) is a kind of aspiration and swallowed poison, that can enter the body through the digestive tract, respiratory, and skin mucous membrane, and may occur after skin contact dermatitis, or allergic phenomena, such as redness, itching, tingling, etc. In view of the harm of Cr (Ⅵ) to the human body, it is an urgent problem to develop a probe that can simultaneously detect two kinds of Cr (Ⅵ) in the environment. Herein, a novel green synthetic 2-amino-5-substituent-1,3, 4-thiadiazole was synthesized. The synthesized 2-amino-5-methyl-1,3, 4-thiadiazole (Probe M) was used as a molecular probe to selectively recognize Cr2O72− and CrO42−, and then the anti-interference detection and quantitative test of Cr2O72− and CrO42− were carried out. The binding ratios of Probe M with Cr2O72− and CrO42− were 1:1 and 2:1, respectively. The complexation constants were 5.8617 × 105 M−1 and 9.328 × 105 M−1, respectively, and the detection limits were 1.3334 × 10−7 M and 1.3046 × 10−7M, respectively. In this paper, 2-amino-5-substituted-1,3,4-thiadiazole was used as a probe to detect Cr (VI) for the first time, also carried on the dipstick experiment observed with the increase of concentration, the color of the paper changed from colorless to yellow, can be used in the “naked eye” identification, the method can be more convenient and quick detection of Cr (VI) solution.