Method for quickly detecting trace polychlorinated biphenyls (PCBs) based on carbon nano tube modification technology

Abstract

The invention relates to a method for quickly detecting trace polychlorinated biphenyls (PCBs) based on a carbon nano tube modification technology, and belongs to the field of analysis and test. Based on the peculiar interaction mechanism among aromatic rings, a carbon nano tube has high capability of trapping the PCBs and low dispersibility in water, and how to quickly separate the carbon nano tube which has micro size and is used as an adsorbent from an analysis object mixture is a problem. The scheme aims to solve the problem. The carbon nano tube involved in the method is subjected to hydrophilic modification and combined with a hydrophilic magnetic nano material to form a composite nano adsorbent in which the modified carbon nano tube is taken as a main body and which has a magnetic response characteristic and high hydrophilicity, the adsorbent in which the PCBs are adsorbed can respond to the action of a magnetic field of a permanent magnet and is quickly separated from a solution, and the residual amount of the trace PCBs in an environment water body is quickly analyzed and detected by combining gas chromatography-mass spectrometry equipment.

Description

Technical field [0001] The invention relates to a method for rapidly detecting trace amounts of polychlorinated biphenyls relying on carbon nanotube modification technology, and belongs to the field of analysis and testing. Background technique [0002] Polychlorinated biphenyls (PCBs) are the chlorine substitutes of biphenyls. They are composed of 209 monomer homologs. They have stable chemical properties and slow degradation in the environment. Although PCBs have ceased to be produced and used globally since 1972, they remain in the environment through various channels and are one of the most important persistent organic pollutants in the world. my country included PCBs in the "Blacklist of Priority Control of Pollutants in Water" in 1989 and implemented the "Pollution Control Standard for Wastes Containing Polychlorinated Biphenyls" (GB13015-1) in 1992. In 1999, PCBs were included in the newly promulgated "Surface Water Environmental Quality Standards" (GHZBI-1999). With the ...

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Problems solved by technology

In 2004, the Zhejiang Provincial Environmental Protection Bureau entrusted the Provincial Environmental Monitoring Station to conduct surveys and statistics. The results showed that 80% of Zhejiang Province was polluted by PCBs toxic substances. It is not easy to detect these pollutants because of their low content. However, PCBs are biologically magnified and cumulative. , easy to cause serious harm to human health, so the development of detection methods and technologies for low-concentration PCBs has become necessary

And the traditional extraction methods of organic pollutants, such as Soxhlet extraction, ultrasonic oscillation extraction, air blowing capture, continuous liquid-liquid extraction and separatory funnel liquid-liquid extraction, although these methods recover The efficiency is high, but the operation is often cumbersome and requires a large amount of organic solvents, which is easy to cause environmental pollution and personal injury to the operator