Arsenic speciation using capillary zone electrophoresis with indirect ultraviolet detection

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Toxicology

Background:

• Trace element speciation is crucial for understanding toxicological and biological impacts.
• Quantification and chemical form analysis of elements like arsenic are vital in environmental samples.

Purpose of the Study:

• To determine various arsenic species, including arsenate, arsenite, dimethylarsinate (DMA), and monomethylarsonate (MMA), using capillary zone electrophoresis (CZE).
• To evaluate the efficiency and sensitivity of CZE for arsenic speciation.
• To analyze arsenic species in a coal fly ash extract.

Main Methods:

• Capillary zone electrophoresis (CZE) with indirect ultraviolet absorption detection.
• Sodium chromate used as electrolyte and chromophore.
• Investigation of pH effects on species separation.

Main Results:

• Achieved low absolute detection limits for arsenic species: 5.2 pg (arsenate), 3.5 pg (arsenite), 15.6 pg (MMA), and 15.6 pg (DMA).
• Analyzed coal fly ash extract, quantifying arsenate at 5 µg/g.
• Arsenite, MMA, and DMA were not detected in the coal fly ash sample.

Conclusions:

• CZE is an efficient and sensitive technique for separating and determining arsenic species.
• The developed method is suitable for analyzing arsenic speciation in environmental samples like coal fly ash.
• Highlights the importance of speciation analysis for accurate risk assessment of trace elements.