Element Detection in Porphyra Yezoensis via Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is applied to detect porphyra yezoensis elements in offshore seawater. The spectrum shows that porphyra yezoensis contains Ca, Mg, Mn, Fe, K, P, Na, Zn, Cu, Sr, Si, O, C, and other elements. To investigate the feasibility of using porphyra yezoensis as a marker of heavy metal pollution in offshore seawater to reflect the degree of pollution, four lead solutions with varying concentrations are prepared to simulate polluted offshore seawater in this experiment, and fresh samples of porphyra yezoensis are immersed in the solutions. The spectra of this contaminated porphyra yezoensis are determined using LIBS. Quantitative analysis is performed using the internal standard method. The correction curve is obtained after fitting. The plasma temperature and electron density are calculated in the experiment to confirm the quantitative work's accuracy as well as the local thermodynamic equilibrium environment is verified. Additionally, CN molecular bands observed in the spectrum of porphyra yezoensis are simulated. Two important parameters of CN molecules are detected: vibrational temperature and rotational temperature. Finally, vibrational temperature, rotational temperature, and plasma temperature are compared and discussed briefly. The results verify the feasibility of applying LIBS to the field of offshore sewage detection.