Arsenic speciation in tree moss by mass spectrometry based hyphenated techniques

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Arsenic speciation in environmental matrices like tree moss is crucial for understanding its biogeochemical cycling and toxicity.
• Previous methods may lack the sensitivity or specificity to identify diverse arsenic compounds in complex biological samples.

Purpose of the Study:

• To develop and validate a highly sensitive analytical method for arsenic speciation in tree moss extracts.
• To identify and quantify known and unknown arsenic species present in tree moss.

Main Methods:

• Ion-pair reversed-phase high-performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was employed.
• Electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-qTOF-MS) was used for structural elucidation of unknown species.

Main Results:

• The developed HPLC-ICP-MS method achieved limits of detection between 0.04–0.07 ng/mL for eight target arsenic species.
• Six known arsenic species (arsenite, arsenate, MMA, DMA, TMAO, Tetra, AsB) and three unknown species were detected in tree moss extract.
• One unknown arsenic species (Unk3) was identified as an arsenosugar (arcanosugar X).

Conclusions:

• The established method provides sensitive and specific arsenic speciation in tree moss.
• The detection of novel arsenosugars highlights the complexity of arsenic metabolism in plants.
• This research contributes to a better understanding of arsenic contamination and transformation in terrestrial ecosystems.