Sensitivity, precision, and accuracy of fs-LIBS for heavy metal detection in flowing aqueous solutions

Abstract

This investigation employs femtosecond laser-induced breakdown spectroscopy (fs-LIBS) to measure the concentrations of chromium (Cr), lead (Pb), and copper (Cu) in flowing aqueous solutions. The fs pulsed laser excites the water, generating plasma in a dynamic setting that prevents liquid splashing-a notable advantage over static methods. The flowing water column maintains a stable liquid level, circumventing the laser focus irregularities due to liquid-level fluctuations. Calibration curves, based on a linear function, reveal limits of detection (LODs) as low as 0.0179 μg/mL for Cr, 0.1301 μg/mL for Pb, and 0.0120 μg/mL for Cu. The reliability of the experiment is confirmed by R² values exceeding 0.99. These findings offer valuable insights for the analysis of trace heavy metals in flowing aqueous solutions using fs-LIBS, demonstrating the technique's potential for environmental monitoring.