The oxidation‐reduction potential of aqueous soil solutions at the Mars Phoenix landing site
The oxidation‐reduction potential of aqueous soil solutions at the Mars Phoenix landing site
复制标题
火星凤凰登陆点土壤水溶液的氧化还原电位
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
M. Hecht
中科院分区：
文献类型：
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作者：
R. Quinn;J. Chittenden;S. Kounaves;M. Hecht
火星凤凰号任务湿化学实验室 (WCL) 的结果用于确定凤凰城 WCL 玫瑰红样品土壤溶液的氧化还原电位 (Eh)。 WCL 测试水溶液中玫瑰红样品的测量 Eh 为 253 ± 6 mV，pH 为 7.7 ± 0.1。测量的溶液 Eh 变化对应于溶液 H+ 活性的变化，这主要由顶空 PCO2 和溶液 CO32−、HCO3− 和 CO2 浓度的变化控制。如果在 PCO2 为 8 mbar 的水中（而不是 WCL 测试溶液）进行测量，则玫瑰红土壤溶液的 Eh 将为 ∼300 mV。使用模拟盐混合物进行的实验室实验结果与可能存在低含量（ppm）金属过氧化物或其他氧化剂相一致，并表明土壤中易溶亚铁的含量低于 1 ppm。
Results from the Mars Phoenix mission Wet Chemistry Laboratory (WCL) are used to determine the oxidation‐reduction potential (Eh) of the Phoenix WCL Rosy Red sample soil solution. The measured Eh of the Rosy Red sample in the WCL aqueous test solution was 253 ± 6 mV at a pH of 7.7 ± 0.1. Measured solution Eh changes correspond to changes in solution H+ activity, which is controlled mainly by changes in headspace PCO2 and solution CO32−, HCO3−, and CO2 concentrations. If measured at a PCO2 of 8 mbar in water, rather than in WCL test solution, the Eh of the Rosy Red soil solution would be ∼300 mV. The results of laboratory experiments using analog salt mixtures are compatible with the possible presence of low levels (ppm) of metal peroxides or other oxidants and indicate that levels of readily soluble ferrous iron in the soil are below 1 ppm.