Suspect and non-target screening of contaminants of emerging concern in streams in agricultural watersheds was written by Tian, Zhenyu;Wark, David A.;Bogue, Kevin;James, C. Andrew. And the article was included in Science of the Total Environment in 2021.Application In Synthesis of 1,3-Dicyclohexylurea This article mentions the following:
Surface water runoff is an important source of water contamination affecting nearby rivers and streams. Many rural creeks are documented habitats for important aquatic species and the focus of restoration activities. In this study, we collected creek water samples in watersheds with a range of com.-to-agricultural land use during rain events, and applied suspect and non-target screening with high-resolution mass spectrometry (HRMS) to characterize the occurrence of contaminants of emerging concern (CECs). In total, 58 CECs were identified, and 36 of them were confirmed and semi-quantified with reference standards Pesticides were detected in all land use, including urban/com. areas. Some pesticides were observed at concentrations of >10,000 ng/L demonstrating the strong contamination input during rain events. Five pesticides (azoxystrobin, fludioxonil, 4-hydroxy-chlorothalonil, imidacloprid, 2-methyl-4-chlorophenoxyacetic acid) were prioritized based on their risk quotients. HRMS chem. profiles demonstrated the wide range of chem. exposures in a given stream system and that compounds associated with specific land uses occur across land uses. Temporal trends suggested that some CECs remain present in creek water for months, resulting in chronic exposures across the life stages of aquatic species. These findings highlight the potential for contamination from agricultural runoff and the associated ecol. risk to aquatic species. Suspect and non-target screening revealed the chronic occurrence of emerging contaminants in streams in agricultural catchments during rain events. In the experiment, the researchers used many compounds, for example, 1,3-Dicyclohexylurea (cas: 2387-23-7Application In Synthesis of 1,3-Dicyclohexylurea).
1,3-Dicyclohexylurea (cas: 2387-23-7) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. The presence of the amide group –C(=O)N– is generally easily established, at least in small molecules. It can be distinguished from nitro and cyano groups in IR spectra. Amides exhibit a moderately intense νCO band near 1650 cm−1. By 1H NMR spectroscopy, CONHR signals occur at low fields. In X-ray crystallography, the C(=O)N center together with the three immediately adjacent atoms characteristically define a plane.Application In Synthesis of 1,3-Dicyclohexylurea
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics