A high-resolution dialysis technique for rapid determination of dissolved reactive phosphate and ferrous iron in pore water of sediments.
A high-resolution dialysis technique for rapid determination of dissolved reactive phosphate and ferrous iron in pore water of sediments.
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DOI：
10.1016/j.scitotenv.2012.01.062
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发表时间：
2012-04
期刊：
影响因子：
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通讯作者：
Di Xu;Wei Wu;S. Ding;Qin Sun;Chaosheng Zhang
中科院分区：
文献类型：
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作者：
Di Xu;Wei Wu;S. Ding;Qin Sun;Chaosheng Zhang
由于沉积物的非均质性，表征孔隙水的化学性质需要在高空间分辨率下测量化学成分。在这项研究中，开发了一种新的高分辨率透析技术，用于快速采样孔隙水中溶解的活性磷酸盐（DRP）和亚铁（Fe），垂直分辨率为2mm。该技术采用了一个微型透析装置（窥视器），在沉积物中放置时间为2天，以达到平衡。回收peeper后的操作程序包括通过喷洒商业二氧化碳雪对孔隙水样品进行原位冷冻，孔隙水样品的冷冻储存，以及使用384孔微孔板光度法对孔隙水样品中的化学物质进行快速分析。每个参数的样品消耗量可降至6μL，可在一个探针装置中同时测定DRP和亚铁。实验室测试表明，该技术足以进行现场测量。随后在中国太湖富营养化浅海湾的三个地点进行了实地部署。同时测定所有地点的DRP和亚铁铁表明，这两种化学物质在孔隙水剖面中具有相似的行为，验证了铁在沉积物中对P动员的控制。
Characterization of pore water chemistry necessitates measurements of the chemical components at a high spatial resolution due to the heterogeneous nature of sediments. In this study, a novel high-resolution dialysis technique was developed for rapid sampling of dissolved reactive phosphate (DRP) and ferrous iron (Fe) in pore water at a vertical resolution of 2mm. This technique employed a mini dialysis device (peeper) with a deployment time of 2days in sediments for equilibration. Operational procedures following retrieval of the peeper include in situ freezing of the pore water samples through spraying commercial carbon dioxide snow, frozen storage of the pore water samples, and quick analysis of chemicals in pore water samples using 384-well microplate photometric methods. The sample consumption for each parameter can be minimized to 6μL, which allowed simultaneous determination of DRP and ferrous iron in a peeper device. Laboratory tests showed that the technique was robust enough for the in situ measurements. Field deployment was subsequently performed in three sites of a shallow, eutrophic bay in Lake Taihu of China. Simultaneous determination of DRP and ferrous Fe in all the sites demonstrated a similar behavior of both chemicals in the pore water profiles, verifying the control of P mobilization by Fe in sediments.