Effect of cavity-confinement and microwave-assistance on laser-induced Cu plasma in pig feed

Excessive heavy metals in pig feed represent a substantial threat to the health of pigs, meat quality, humans who consume the meat, and the environment. In this paper, a method to improve the detection of heavy metal (Cu) in pig feed is introduced and investigated. It uses laser-induced breakdown spectroscopy (LIBS) combined with cavity-confinement and microwave-assistance to increase the intensity of the spectrum used for analysis. The test results show that, compared to conventional LIBS, the characteristic spectral intensity and the signal-to-noise ratio (SNR) for the Cu I 324.75 nm line can be increased 32.3-fold and 22.2-fold, respectively. The plasma temperature measured using the Boltzmann diagram method is 1677 K higher than the microwave-assistance method (alone). These results show that the combined application of cavity-confinement and microwave-assistance can increase the characteristic spectral intensity, the SNR, and the plasma temperature associated with elemental Cu in pig feed, which is generally not easy to detect. This study also offers theoretical guidance for the rapid characterization (and improvement) of pig feed, which contains Cu, using LIBS.

Automated summary

Excessive heavy metals in pig feed pose a significant threat to pigs' health, meat quality, humans consuming the meat, and the environment. This paper introduces and investigates a method to improve the detection of copper in pig feed using laser-induced breakdown spectroscopy (LIBS) combined with cavity-confinement and microwave-assistance. The results show that the combined approach enhances the spectral intensity and signal-to-noise ratio for copper detection in pig feed, providing theoretical guidance for rapid characterization and improvement of pig feed.