The metal pollution in water seriously endangers human health, so the detection of heavy metal in water is significance. Surface-enhanced laser-induced breakdown spectroscopy (SENLIBS), as atomic emission spectroscopy, has the advantages of rapidity and high detection sensitivity. However, the spectral enhancement effect of different substrates was reported, but the effect of the physical properties of the substrate on the detection sensitivity in SENLIBS has not been investigated.
To investigate the effect of substrate physical properties on the detection sensitivity in SENLIBS, L. B. Guo and S. X. Ma et al. used Zn, Mg, Ni, and Si substrates to establish the relationship between the boiling point of the substrate and the detection sensitivity. The Cr and Pb elements in aqueous solution were analyzed as two examples. The results indicated the spectral intensity of heavy metal elements on different substrates is strongly positively correlated with the boiling point of the substrate. The higher plasma temperature and electron density were obtained on the substrate with a low boiling point. As a result, the LoDs of 0.0011 mg/L and 0.004 mg/L for Cr and Pb were obtained on an optimal Zn substrate, respectively. The LoDs were sufficiently low to meet the drinking water sanitation standard of China (0.01 mg/L for Pb and 0.05 mg/L for Cr, GB5749-2006).
Fig. 1. (a) liquid-solid conversion, (b) The spectra of Cr, (c) Correlation between the detection limit of Cr element and boiling point.
The paper “Determination of trace heavy metal elements in aqueous solution using surface-enhanced laser-induced breakdown spectroscopy” was published on Optics Express, and funded by National Natural Science Foundation of China (61575073).
