Development of a Manganese Speciation Method for Atmospheric Aerosols in Biologically and Environmentally Relevant Fluids
Because the health effects of manganese are dependent its oxidation-state, we have improved upon oxidation-state resolved methods to quantify soluble manganese in atmospheric aerosols. Two spectrophotometric methods were adapted for measurements in atmospheric aerosols in order to measure total solu...
Gespeichert in:
Veröffentlicht in: | Aerosol science and technology 2007-10, Vol.41 (10), p.925-933 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Because the health effects of manganese are dependent its oxidation-state, we have improved upon oxidation-state resolved methods to quantify soluble manganese in atmospheric aerosols. Two spectrophotometric methods were adapted for measurements in atmospheric aerosols in order to measure total soluble manganese (Mn
sol
) and soluble oxidized manganese [Mn(III) and Mn(IV), Mn
ox
]. Using the formaldoxime method, we noted a detection limit two orders of magnitude better than past studies using trace-metal clean techniques and a 1 meter path-length spectrophotometric cell. Extractions of co-located aerosol samples were performed in four environmentally or biologically relevant extract solutions and processed for soluble manganese analysis. The quantity of manganese extracted was a strong function of the fluid, and the greatest amount of manganese was extracted in the rain-water surrogate (acetate buffered solution). Mn
sol
in East St. Louis, IL, USA (6-20% of the total manganese) was less than the Mn
sol
in aerosols collected in Toronto, ON, Canada (40% of the total). Mn
ox
was not detected in the PM10 samples collected in East St. Louis, however Mn
ox
accounted for around 30% of the PM2.5 soluble manganese in Toronto. Mn
ox
was not detected in the coarse fraction in Toronto, which may imply that soils are not a source of Mn
ox
at this site. Oxidized manganese was not recoverable from extracts of samples from East St. Louis spiked with 1 μg Mn
ox
L
−1
. This implies that a soluble component of the aerosol is responsible for reduction of oxidized manganese and that the chemical form of manganese in aerosols can quickly change when it comes into contact with a fluid. |
---|---|
ISSN: | 0278-6826 1521-7388 |
DOI: | 10.1080/02786820701564657 |