Exceedingly Rapid Enrichment of Organochlorine Pollutants in Complex Samples Using Amino-Functionalized Carbon Nanotubes

Abstract

Organochlorine pesticides have made a large contribution to the development of modern agriculture but also caused contamination in the environment, and they persistently cause harm to humans and organisms due to their stability in nature. Precise tracking and enrichment of these pollutions are therefore clearly required. In this work, we explored an amino-functionalized multiwalled carbon nanotube (MWCNT-NH2) to selectively trap and rapidly enrich trace organochlorine contaminants from aqueous solutions. Through a case study of trace hexachlorocyclohexane (HCH) enrichment, it is demonstrated that an MWCNT-NH2 exhibits ultrafast capture kinetics (96.5% removed in 30 s), where a high uptake rate (98.5%), an outstanding uptake capacity (197.9 mg g–1), and an excellent selectivity in complex samples are obtained, and a high uptake efficiency is maintained over a wide range of harsh conditions (pH 2–10). This capturer can be further conveniently separated by a simple filtration. Importantly, an MWCNT-NH2 can be applied to efficiently enrich HCH in samples with much low temperatures (≤4 °C). This study introduces a new avenue for enrichment and separation of trace organic contaminants and also holds promise for developing highly efficient sensors, detectors, and scavengers of harmful compounds.