Method and device for detecting liquid sample by using ultrasonic atomization and breakdown spectroscopy

Abstract

The invention relates to a method and device for detecting liquid samples by using breakdown spectroscopy. The device utilizes the ultrasonic atomization method to atomize the liquid samples to form massive and dense droplets in the air, breaks down and induces plasma and radiates an emission spectra signal. The method comprises the following steps: high-frequency oscillation is generated by the ultrasonic transducer (3) of the device of the invention to ensure that the liquid samples (4) in a sample cell (5) generate fog droplets, with the aid of a supply fan and an exhaust fan (13), columnar mist is generated above an air duct (6); plasma is generated at the edge of the columnar mist through breakdown, the plasma emission spectra signal is collected by a collection lens (7) and enters a spectrograph (9) through optical fiber (8) to split light; and finally a photoelectric sensor (11) fits with an ICCD detector (10) to collect spectral data. The method of the invention can reduce the breakdown threshold, increase the ablation efficiency and prolong the life of plasma. The detection device is applicable to the field component detection analysis field of the environment and mineral resources and the detection method has higher signal-to-background ratio and lower cost compared with the similar methods.

Description

technical field [0001] The invention belongs to the technical field of on-site chemical component detection and analysis. Specifically, it is a technology to detect the chemical composition of liquid samples by using ultrasonic atomization to assist the breakdown plasma spectroscopy detection method. This technology can be used in the detection of on-site mineral resources or water pollution in oceans, lakes or rivers. It can also be applied to the monitoring of heavy metal components in sewage discharged from various factories, and it can also be used in food and drug inspection and other fields. Background technique [0002] The technique of generating plasma by breaking down the sample, and detecting its emission spectrum during the process of plasma cooling and recombination, so as to detect and analyze the composition of the sample is called breakdown spectroscopy. Compared with other component detection and analysis techniques, breakdown spectroscopy has attracted wid...

AI Technical Summary

Problems solved by technology

When detecting the composition of liquid samples, due to the high conductivity of the liquid itself, the spark-induced breakdown spectroscopy technology itself cannot be developed.

For laser-induced breakdown spectroscopy, many studies have shown that factors such as the internal pressure of the liquid will shorten the life of the plasma, thereby affecting the sensitivity of the detection; and the impact of factors such as transmission, scattering, and absorption of the laser pulse after entering the liquid and before the breakdown , making its ablation efficiency in the liquid lower, which requires a higher breakdown energy density

Although the double-pulse laser-induced breakdown spectroscopy technology can solve the above problems to a certain extent, it needs to use a double-pulse laser or two pulse lasers, which is relatively expensive and its operation process is relatively complicated.

Images