Dark production of hydrogen peroxide in the Gulf of Alaska

作者：Vermilyea Andrew W; Hansard S Paul; Voelker Bettina M^*

来源：Limnology and Oceanography, 2010, 55(2): 580-588.

DOI：10.4319/lo.2009.55.2.0580

Dark H(2)O(2) production rates were measured in samples collected in the Gulf of Alaska. We used a simple, novel method for determining absolute rates of dark production and decay of H(2)O(2), both of which are occurring simultaneously (presumably as a result of biological activity) in unfiltered samples. [H(2)O(2)] vs. time was measured in 24-h dark incubations of both unaltered samples and the same samples spiked with 100-250 nmol L(-1) H(2)O(2). Data were modeled with zero-order H(2)O(2) production rates and first-order H(2)O(2) decay coefficients as fitting parameters, with the assumption that addition of [H(2)O(2)] to a sample does not change either parameter. H(2)O(2) production rates ranged from < 0.5 nmol L(-1) h(-1) to 8 nmol L(-1) h(-1), and generally decreased with depth and decreasing chlorophyll. Comparison of dark production with estimates of average photochemical H(2)O(2) production rates in the top 50 m of the water column indicated that dark production is likely to be a significant source of H(2)O(2). Indeed, many of the unaltered incubations indicated that in situ [H(2)O(2)] was close to a steady state between dark production and decay, especially in samples from depths of >= 10 m.

• 出版日期2010-3