New Technique for Online Measurement of Water-Soluble Fe(II) in Atmospheric Aerosols

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• 作者：Neeraj Rastogi^† ; ; Michelle M. Oakes^† ; ; James J. Schauer^‡ ; ; Martin M. Shafer^‡ ; ; Brian J. Majestic^‡ ; ; Rodney J. Weber*
• 刊名：Environmental Science & Technology
• 出版年：2009
• 出版时间：April 1, 2009
• 年：2009
• 卷：43
• 期：7
• 页码：2425-2430
• 全文大小：201K
• 年卷期：v.43,no.7(April 1, 2009)
• ISSN：1520-5851

文摘

A prototype instrument has been developed for online analysis of water-soluble Fe(II) (WS_Fe(II)) in atmospheric aerosols using a particle-into-liquid-sampler (PILS), which concentrates particles into a small flow of purified water, coupled with a liquid waveguide capillary cell (LWCC) and absorbance spectrophotometry to detect iron−ferrozine colored complexes. The analytical method is highly precise (<3% RSD), and the overall measurement uncertainty and limit of detection for the complete PILS−LWCC system are estimated at 12% and 4.6 ng m⁻³, respectively. The online measurements compared well with those of 24 h integrated filter samples collected at two different sampling sites (n = 27, R² = 0.82, slope 0.90 ± 0.08, and intercept 3.08 ± 1.99 ng m⁻³). In urban Atlanta, fine particle WS_Fe(II) concentrations measured every 12 min exhibited large variability, ranging from below the detection limit (4.6) to 370 ng m⁻³ during a 24 day period in June 2008. This instrument provides new capabilities for investigating the sources and atmospheric processing of fine particle WS_Fe(II) and may prove useful in studies ranging from effects of particle WS_Fe(II) on human health to effects of particle WS_Fe(II) on atmospheric chemistry and ocean biogeochemistry.