Development and application of DGT devices for passive sampling of contaminated waters in the Antarctic environment

Metadata record for data from ASAC Project 2385
See the link below for public details on this project.

---- Public Summary from Project ----
Facilities for chemical analysis of environmental samples in Antarctica are limited, with samples frequently shipped at great expense to Australia for analysis. Development of a technique to concentrate metals from environmental samples into a thin film which can be easily transported to a laboratory for analysis is currently underway.

DGT stands for Diffusive gradients in thin films, they are a passive sampling technique for trace metals based on Fick's First Law of diffusion. Basically the theory being the method: Zhang, H. and Davison, W., Anal Chem, 1995, 67, 3391-400 and Davison, W. and Zhang, H., Nature (London), 1994, 367, 546-8.

Description of spreadsheets:

All data were collected using DGT sediment probes or water samplers prepared from polyacrylamide diffusion layer (0.8 mm thickness, covered with a 0.13 mm thick membrane filter) and Chelex 100 binding layer (0.4 mm thick).

Metadata 0304 sediment -
DGT sediment probes were deployed during the 0304 summer. Samples were deployed in a 3 x 2 back-to-back array at the inner and outer sites in Brown and O'Brien Bay. ie 1.1 and 1.2 are back to back pair. All samplers were deployed for 34 days. More accurate date are on the attached s'sheet. Results shown are nanograms of metals per square centimetre accumulated in the samplers at a resolution of 2 cm. The detection limits of the metals for the samplers are based on 3 x stdev of the field blank probes. Where value = &nd& the value was less than the method detection limit.

Metadata 0304 sediment Characterisation -
Cores were sampled in Dec 2003 - Jan 2004 from Casey Station region. All characterisation was performed on the same 1 cm slices of core. Cores were sampled and analysed in anoxic conditions.

Latitudes and Longitudess
Brown Bay inner66.2803 S, 110.5414 E

Brown Bay outer66.2802 S, 110.5451 E

O'Brien Bay inner66.3122 S, 110.5147 E

O'Brien Bay outer66.3113 S, 110.5162 E

Metadata 0203 sediment -
Results shown are sediment profile in nanograms of metals per square centimetre accumulated in the samplers at a resolution of 1 m. Samples 1.x were deployed for 5 days before the summer melt, 2.x were deployed for 10 days before the melt, 3.x were deployed for 15 days before the melt, 4.x were deployed for 21 days before the melt, 5.x were deployed for 28 days before the melt, 6.x were deployed for 5 days during the melt and 7.x were deployed for 20 days during the melt. The detection limits of the metals for the samplers are based on 3 x stdev of the field blank probes. Where value = 'nd' the value was less than the method detection limit.

Metadata 0304 water -
Results show metals in DGT water samplers deployed for 28 days. Actual times are on spreadsheet attached. Samplers were deployed in triplicate at three depths in the water column, with the depth from the sed bed meaning metres above the sea bed in the water column. Values in the original spreadsheet is nanograms of metals accumulated in sampler of 3.14cm2 area. The detection limits of the metals for the samplers are based on 3 x stdev of the field blank. Where value = 'nd' the value was less than the method detection limit.

Metadata 0203 water -
Results show metals in DGT water samplers deployed for 8 days. Samplers were deployed in triplicate at three depths in the water column. Depth from seabed is a measure of distance from the sea bed to the deployment depth in the water column. Values in the original spreadsheet is nanograms of metals accumulated in sampler of 3.14cm2 area. The detection limits of the metals for the samplers are based on 3 x stdev of the field blank. Where value = 'nd' the value was less than the method detection limit.

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One thing to note, although the metal isotopes are listed, ie Cd111(LR), this is still a measure of the elemental Cd (ie all isotopes), it is just how the ICP-MS analyst presents the data when I get the raw data back. I probably should have corrected this by remove the number to remove any ambiguity involved.

A pdf file of supplementary figures created from the raw data are also included as a download file. Explanations of the figures are presented below.

Supplementary Data Figure Captions

Figure S1. 2002 - 03 DGT water sampling results for Cd, Fe and Ni, before the melt (upper) and during the melt (lower). BB Brown Bay, OBB O'Brien Bay, top top depth, mid middle depth, bot bottom depth. Error bars represent minimum and maximum values based on three replicates and horizontal line is the detection limit based on 3s

Figure S2. 2002 - 03 DGT uptake results for Mn, Fe and As in Brown Bay (upper) and O'Brien Bay (lower) for various deployment times

Figure S3. 2003 - 04 DGT sediment probes results for Brown Bay outer. Upper axis represents maximum porewater concentration assuming no resupply; symbols are for 6 replicate DGT probes. Detection limit, based on 3s is represented by vertical line

Figure S4. 2003 - 04 DGT sediment probes results for O'Brien Bay inner. Upper axis represents maximum porewater concentration assuming no resupply; symbols are for 6 replicate DGT probes. Detection limit, based on 3s is represented by vertical line

Figure S5. 2003 - 04 DGT sediment probes results for O'Brien Bay outer. Upper axis represents maximum porewater concentration assuming no resupply; symbols are for 6 replicate DGT probes. Detection limit, based on 3s is represented by vertical line

Figure S6. Sediment porewater concentrations from replicate Brown Bay outer cores

Figure S7. Sediment porewater concentrations for O'Brien Bay inner (open circles) and outer (closed circles)

ASAC项目2385数据集元数据记录
有关该项目的公开详情，请参阅下方链接。

---- 项目公开摘要 ----
南极洲环境样品化学分析设施资源匮乏，样品往往需要耗费巨额成本运往澳大利亚开展分析工作。目前正研发一种可将环境样品中的金属富集至薄膜中的技术，该薄膜可便捷运送至实验室完成分析。

DGT（Diffusive gradients in thin films，薄膜扩散梯度技术）是一种基于费克第一扩散定律的痕量金属被动采样技术。该方法的理论基础详见以下文献：Zhang, H. 与 Davison, W. 发表于《Anal Chem》1995年第67卷第3391-400页，以及 Davison, W. 与 Zhang, H. 发表于《Nature (London)》1994年第367卷第546-548页。

电子表格说明：
所有数据均采用DGT沉积物探针或水体采样器采集，该类采样器由聚丙烯酰胺扩散层（厚度0.8 mm，表面覆盖0.13 mm厚的微孔滤膜）与Chelex 100螯合层（厚度0.4 mm）制备而成。

元数据0304沉积物数据集：
2003-2004夏季科考季期间部署了DGT沉积物探针。采样点设置于布朗湾（Brown Bay）与奥布莱恩湾（O'Brien Bay）的内湾与外湾区域，采用3×2背靠背阵列布局。例如1.1与1.2即为一组背靠背采样对。所有采样器的部署时长均为34天。更精确的部署日期详见所附电子表格。展示结果以每平方厘米采样器中富集的金属纳克数为单位，空间分辨率为2 cm。该类采样器的金属检测限基于野外空白探针的3倍标准偏差（3×stdev）计算得出。若数值标注为‘nd’，则表示该值低于方法检测限。

元数据0304沉积物表征数据集：
沉积物柱样于2003年12月至2004年1月在凯西站区域采集。所有表征分析均针对同一组1 cm厚度的柱样切片开展。柱样的采集与分析均在厌氧条件下进行。

经纬度信息：
布朗湾内湾：南纬66.2803°，东经110.5414°
布朗湾外湾：南纬66.2802°，东经110.5451°
奥布莱恩湾内湾：南纬66.3122°，东经110.5147°
奥布莱恩湾外湾：南纬66.3113°，东经110.5162°

元数据0203沉积物数据集：
展示结果为沉积物剖面数据，以每平方厘米采样器中富集的金属纳克数为单位，垂直分辨率为1 m。采样组1.x的部署时长为夏季融冰前5天，组2.x为融冰前10天，组3.x为融冰前15天，组4.x为融冰前21天，组5.x为融冰前28天，组6.x为融冰期间5天，组7.x为融冰期间20天。该类采样器的金属检测限基于野外空白探针的3倍标准偏差计算得出。若数值标注为‘nd’，则表示该值低于方法检测限。

元数据0304水体数据集：
展示结果为部署时长28天的DGT水体采样器中检测到的金属含量。实际部署时长详见所附电子表格。采样器在水柱的三个深度处以三重重复方式部署，此处标注的水深指相对于海床的高度（单位：米）。原始电子表格中的数值为面积3.14 cm²的采样器中富集的金属纳克数。该类采样器的金属检测限基于野外空白探针的3倍标准偏差计算得出。若数值标注为‘nd’，则表示该值低于方法检测限。

元数据0203水体数据集：
展示结果为部署时长8天的DGT水体采样器中检测到的金属含量。采样器在水柱的三个深度处以三重重复方式部署。此处标注的水深指采样点相对于海床的垂直距离。原始电子表格中的数值为面积3.14 cm²的采样器中富集的金属纳克数。该类采样器的金属检测限基于野外空白探针的3倍标准偏差计算得出。若数值标注为‘nd’，则表示该值低于方法检测限。

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请注意：尽管数据中列出了金属同位素（如Cd111(LR)），但该结果实际代表的是总镉元素（即所有同位素的总和），仅为电感耦合等离子体质谱（ICP-MS）分析人员在返回原始数据时的呈现方式。本应移除同位素编号以避免歧义，特此说明。

此外，本数据集还包含一份由原始数据生成的补充插图PDF下载文件，插图说明如下。

补充数据插图说明：
图S1：2002-2003年融冰前（上图）与融冰期间（下图）DGT水体采样检测的镉（Cd）、铁（Fe）与镍（Ni）结果。BB代表布朗湾，OBB代表奥布莱恩湾，top代表表层水深，mid代表中层水深，bot代表底层水深。误差棒表示三次重复采样的极值，水平线代表基于3倍标准偏差计算的检测限。
图S2：2002-2003年不同部署时长下，布朗湾（上图）与奥布莱恩湾（下图）中DGT采样富集的锰（Mn）、铁（Fe）与砷（As）结果。
图S3：2003-2004年布朗湾外湾DGT沉积物探针检测结果。纵轴代表假设无补给条件下的最大孔隙水浓度；数据点为6次重复DGT探针采样结果。基于3倍标准偏差计算的检测限以垂直线表示。
图S4：2003-2004年奥布莱恩湾内湾DGT沉积物探针检测结果。纵轴代表假设无补给条件下的最大孔隙水浓度；数据点为6次重复DGT探针采样结果。基于3倍标准偏差计算的检测限以垂直线表示。
图S5：2003-2004年奥布莱恩湾外湾DGT沉积物探针检测结果。纵轴代表假设无补给条件下的最大孔隙水浓度；数据点为6次重复DGT探针采样结果。基于3倍标准偏差计算的检测限以垂直线表示。
图S6：布朗湾外湾重复采集的沉积物柱样孔隙水浓度结果。
图S7：奥布莱恩湾内湾（空心圆圈）与外湾（实心圆圈）的沉积物孔隙水浓度结果。