The smoke of burning mosquito-repellent incense was taken as an example for the local air pollution to be detected and analyzed in situ and in real time. And the spectra of the ambient air, human breathing, and smoke were detected in situ with the LIBS technique. There are some additional spectral lines being found in human breathing, such as the C, H_β line, and the CN molecular bands. Some characteristic peaks of the elements Fe, Ca, Ti, Sr, and Cr have been observed in the smoke. Moreover, the vibrational and rotational temperature of the CN molecule were calculated. The mosquito-repellent incense was dipped into the solutions containing Mn and Pb to simulate heavy metal pollution in the atmosphere.

Volatile organic compounds (VOCs) are one of the major pollutants in the atmospheric and indoor environment. The direct detection of halogen atoms in VOCs via laser induced breakdown spectroscopy (LIBS) is highly challenging work because of the high ionization energy of these halogen elements. In this paper, the LIBS system combined with a self-designed single particle aerosol mass spectrometry (SPAMS) system were applied to the direct online detection of VOCs in the atmosphere. The experimental parameters of LIBS experiment were optimized in the measurement of ambient air. Under the best experimental conditions, the characteristic peaks of nitrogen, hydrogen, oxygen, as well as argon, were observed in the LIBS spectra of air. Then, LIBS and SPAMS measurements were performed on Halon 2402, Freon R11 and iodomethane samples under the atmospheric pressure. The characteristic spectral lines of fluorine, chlorine, bromine and iodine were observed and recorded in LIBS spectra. The SPAMS measurements also provide the elemental compositional information of individual VOCs aerosol particles in real time, which is an effective supplement to LIBS analysis. In addition, the different isotopes of bromine and chlorine can be clearly distinguished at the same time. Finally, the home-built portable Raman spectrometer was utilized to analyze the vibrational modes and get the “spectral fingerprint” of VOCs. All the results indicate that the direct online detection performed by the LIBS and SPAMS techniques could provide elemental and isotopic information of halogen atoms in atmospheric VOCs.

The global increase in plastic waste, exceeding 400 million tons annually, underscores the urgent need for efficient plastic sorting and recycling. Laser-induced breakdown spectroscopy (LIBS) shows potential in this area, but its practical application is limited by challenges such as plasma fluctuations and low robustness. To address these limitations, we introduce laser-induced plasma acoustic (LIPA) signals and propose the frame-segmentation LIPA (FLIPA) algorithm to enhance LIBS analysis. This innovative algorithm reduces the number of variables in LIPA by 99% while optimizing computational efficiency and classification accuracy. Additionally, a multimodal fusion technique, LIBS-FLIPA, is developed to integrate LIBS and FLIPA at the feature level. The results indicate that LIBS-FLIPA significantly improves classification accuracy, robustness, and generalization, effectively mitigating overfitting risks. This study provides novel, to the best of our knowledge, solutions to challenges in LIBS analysis and proposes an innovative approach for robust plastic sorting, advancing the methodologies of LIBS research.