Determination of trace heavy metal elements in aqueous solution using surface-enhanced laser-induced breakdown...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Heavy metal pollution poses significant risks to human health and aquatic ecosystems.
• Surface-enhanced laser-induced breakdown spectroscopy (SENLIBS) is a promising technique for detecting trace heavy metals in water.
• Optimizing substrate properties is crucial for improving SENLIBS sensitivity.

Purpose of the Study:

• To investigate the relationship between substrate physical properties and heavy metal detection sensitivity in SENLIBS.
• To explore the mechanism of spectral enhancement by different substrates.
• To identify optimal substrates for sensitive heavy metal analysis in aqueous solutions.

Main Methods:

• Comparison of four substrates: zinc (Zn), magnesium alloy (Mg), nickel (Ni), and silicon (Si).
• Investigation of spectral enhancement mechanisms in SENLIBS.
• Determination of limits of detection (LoD) for heavy metal elements on various substrates.

Main Results:

• The limit of detection (LoD) for heavy metals is inversely proportional to the substrate's boiling point.
• Lower boiling point substrates (e.g., Zn) yield higher plasma excitation temperature and electron density, enhancing spectral signals.
• The optimal Zn substrate achieved LoDs of 0.0011 mg/L for chromium (Cr) and 0.004 mg/L for lead (Pb).

Conclusions:

• Substrate selection is critical for enhancing heavy metal detection sensitivity in SENLIBS.
• Lower boiling point substrates are superior for achieving lower limits of detection.
• The developed SENLIBS method with an optimal substrate meets stringent drinking water quality standards.