Determination of Elemental Concentrations in Lichens Using ICP-AES/MS

Area of Science:

• Environmental Science
• Analytical Chemistry
• Biomonitoring

Background:

• Lichens are sensitive biomonitors of atmospheric element deposition due to their high accumulation capabilities.
• Air pollution in North China has led to elevated elemental concentrations in lichen thalli, necessitating optimized analytical methods.
• Accurate multi-element concentration data in lichens is crucial for effective air quality assessment.

Purpose of the Study:

• To develop and propose an optimized protocol for analyzing 31 elements in lichen thalli using Inductively Coupled Plasma-Atomic Emission Spectroscopy/Mass Spectrometry (ICP-AES/MS).
• To address the challenges posed by high elemental concentrations in lichens from heavily polluted regions.

Main Methods:

• Utilized microwave digestion coupled with ICP-MS for the analysis of 22 elements.
• Employed ashing-alkali fusion digestion followed by ICP-AES for the determination of 9 elements.
• Leveraged the distinct sensitivities and detection limits of ICP-MS and ICP-AES for element-specific analysis.

Main Results:

• Successfully identified 22 elements (e.g., Cd, Pb, Zn, Cu) using microwave digestion-ICP-MS.
• Quantified 9 elements (e.g., Al, Ca, Fe, Ti) via ashing-alkali fusion digestion-ICP-AES.
• Established a comprehensive protocol for multi-element analysis in lichen biomonitors.

Conclusions:

• The proposed ICP-AES/MS protocol is effective for analyzing a wide range of elements in lichen samples, even those with high concentrations.
• This method provides essential data for understanding atmospheric element deposition and air quality in polluted areas.
• Optimized analytical techniques are vital for accurate biomonitoring using lichens.