Detection of heavy metal Cr in soil by the femtosecond filament induced breakdown spectroscopy

Abstract

In this paper, the element content detection of heavy metal Cr in soil is investigated experimentally by femtosecond filament induced breakdown spectroscopy (FIBS). The plasma filament length is measured using the fluorescence method, and the spatial distribution of Cr 425.5 nm spectral intensity is obtained at lens focal lengths 150 mm and 1000 mm. A calibration curve of the heavy metal element Cr in the soil is obtained based on experimental results. Results demonstrate that the relative deviation of the quantitative analytic result from the standard value is smaller than 5%, and the detection limit of Cr in soil is 7.85 ppm at the laser repetition rate 1 kHz. The femtosecond laser filaments induced breakdown spectroscopy is entirely feasible for quantitative detection of heavy metal element Cr in the soil.