Method for detecting polychlorinated biphenyl by using silver nanometer tree branches and leaves

Abstract

The invention discloses a method for detecting polychlorinated biphenyl by using silver nanometer tree branches and leaves. In the method, the silver nanometer tree branches and leaves are involved, and the method comprises the following steps of: irradiating a silver nano-film by using laser with the wavelength of 450 to 550 nm and the power density of 1 to 9*10<5> W / cm<2> as a light source, wherein the silver nano-film is positioned on the focal plane of a microscope of a micro-confocal Raman testing system, absorbs the polychlorinated biphenyl, has the thickness of more than or equal to 1.5 mu m and consists of the silver nanometer tree branches and leaves; and scanning Raman scattering signals of the silver nano-film, performing data integration on the acquired scanned signals, wherein the scanning range is between 500 and 1,800 waves, and the time for the data integration is 0.5 to 1.5 hours, transmitting a data integration result to a charge-coupled device of the micro-confocal Raman testing system and then obtaining the content of the polychlorinated biphenyl by using spectral information displayed by the charge-coupled device. The method has the advantages of simple process, quick and easy implementation, high accuracy and the capacity of performing persistent toxic pollutant detection on trace amount of 209 isomers of the polychlorinated biphenyl.

Description

technical field [0001] The invention relates to a method for detecting polychlorinated biphenyls, in particular to a method for detecting polychlorinated biphenyls by using silver nanometer branches and leaves. Background technique [0002] Polychlorinated biphenyl (PCB) is a general term for many chlorine-containing compounds of biphenyls. In polychlorinated biphenyls, some of the hydrogen atoms on the benzene ring are replaced by chlorine atoms, and the general formula is C 12 h n Cl (10-n) (0≤n≤9). Depending on the number and position of chlorine atoms, there are 209 isomers in PCBs, and these isomers range from single chlorine atom substitution to fully substituted decachlorobiphenyl. [0003] PCBs remain in the environment for a long time and can migrate over long distances. They are fat-soluble and bioaccumulative. They are highly toxic to humans and wild animals and plants. The harm to humans is mainly manifested in endocrine disruption, immune toxicity, and repro...

AI Technical Summary

Problems solved by technology

However, both the active substrate, its preparation method, and the use of the active substrate for trace detection have shortcomings. First, the active substrate can only be used for monolayer molecular membranes, such as monolayer octadecanoic acid molecular membranes. Raman signal measurement, but can not use the enhanced Raman effect on the surface of its structure to detect PCBs; secondly, the preparation method can not prepare active substrates that can detect PCBs, and because the prepared silver product is combined with the substrate Strong, so that it needs to rely on the support of the substrate when used; again, trace detection is only suitable for water, which not only increases the complexity of the detection, but also makes it difficult to guarantee the measurement results due to the dissolution and dilution of the measured substance by water the accuracy of

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