Cation Data for the East River Watershed, Colorado (2014-2021)

This data package contains mean values for cation concentration for water samples taken from the East River Watershed in Colorado. Inductively coupled plasma mass spectrometry (ICP-MS) has been used to measure the concentrations of 37 elements of interest simultaneously for the East River Watershed, Colorado groundwater and surface water samples to inform insights on the biogeochemistry processes within the watershed. The East River is part of the Watershed Function Scientific Focus Area (WFSFA) located in the Upper Colorado River Basin, United States. Inductively coupled plasma mass spectrometry (ICP-MS) has been used to measure the concentrations of 37 elements of interest simultaneously for Rifle and East River Watershed, Colorado groundwater and surface water samples. The instrumentation, Elan DRC II, PerkinElmer SCIEX, automatically switches among the three models necessary to analyze all 37 elements. These 37 elements include: (1) Lithium (Li), Beryllium (Be), Boron (B), Soldium (Na), Magnesium (Mg), Aluminium (Al), Silicon (Si), Phosphorus (P), Titanium (Ti), Cobalt (Co), Nickel (Ni), Copper (Cu), Zinc (Zn), Germanium (Ge), Arsenic (As), Rubidium (Rb), Strontium (Sr), Zirconium (Zr), Molybdenum (Mo), Silver (Ag), Cadmium (Cd), Tin (Sn), Antimony (Sb), Caesium (Cs), Barium (Ba), Europium (Eu), Lead (Pb), Thorium (Th), Uranium (U) using santadard model, argon Ar as reaction gas, (2) Potassium (K), Calcium (Ca), Vanadium (V), Chromium (Cr), Manganese (Mn), Iron (Fe) using dynamic reaction cell (DRC) model, ammonia NH3 as reaction gas, and (3) Phosphorus (P) and Selenium (Se) using DRC model, oxygen O2 as reaction gas. Note for the samples with higher concentrations of chloride (Cl-), asenic (As) concentrations were analysed with DRC model (oxygen O2 as reaction gas) to avoid the interference of chloride. All samples were prepared/diluted with 2% (v/v) ultrapure nitric acid in Milli-Q water (18.2 mega ohm-cm), and analyzed under a rigorous quality assurance and quality control (QA/QC) process. This data package contains (1) a zip file (cation_data_2014-2021.zip) containing a total of 4,517 files: 4,516 data files of cation data from across the Lawrence Berkeley National Laboratory (LBNL) Watershed Function Scientific Focus Area (SFA) which is reported in .csv files per location and a locations.csv (1 file) with latitude and longitude for each location; (2) a file-level metadata (flmd.csv) file that lists each file contained in the dataset with associated metadata; and (3) a data dictionary (dd.csv) file that contains terms/column_headers used throughout the files along with a definition, units, and data type. There are a total of 99 locations containing isotope data. Update on 4/11/2021, Added Detemination of Method Detection Limits (MDLs) for ICP-MS document, which can be accessed as a PDF or with Microsoft Word. Update on 6/10/2022: versioned updates to this dataset was made along with these changes: (1) updated cation data for all locations up to 2021-12-31, (2) removal of units from column headers in datafiles, (3) added row underneath headers to contain units of variables, (4) removed suffix and prefix on two variables (“aqberylliumion_asberyllium” and “aqlithiumion_aslithium”), (5) added -9999 for empty numerical cells, and (6) the addition of the file-level metadata (flmd.csv) and data dictionary (dd.csv) were added to comply with the File-Level Metadata Reporting Format. Update on 2022-09-09: Updates were made to reporting format specific files (file-level metadata and data dictionary) to correct swapped file names, add additional details on metadata descriptions on both files, add a header_row column to enable parsing, and add version number and date to file names (v2_20220909_flmd.csv and v2_20220909_dd.csv).

本数据包包含取自美国科罗拉多州东河流域的水样阳离子浓度均值。研究采用电感耦合等离子体质谱法（Inductively coupled plasma mass spectrometry，ICP-MS），同时测定科罗拉多州东河流域地下水与地表水样品中37种目标元素的浓度，以解析该流域内的生物地球化学过程。东河隶属于美国科罗拉多河上游流域的流域功能科学重点区域（Watershed Function Scientific Focus Area，WFSFA）。

此前研究还采用ICP-MS对科罗拉多州赖夫尔（Rifle）与东河流域的地下水、地表水样品中37种目标元素开展同步浓度测定。所用仪器为PerkinElmer SCIEX公司的Elan DRC II，可自动切换三种分析模式以完成全部37种元素的检测：
1. 采用标准模式、以氩气（Ar）作为反应气，检测锂（Li）、铍（Be）、硼（B）、钠（Sodium，Na）、镁（Mg）、铝（Al）、硅（Si）、磷（P）、钛（Ti）、钴（Co）、镍（Ni）、铜（Cu）、锌（Zn）、锗（Ge）、砷（Arsenic，As）、铷（Rb）、锶（Sr）、锆（Zr）、钼（Mo）、银（Ag）、镉（Cd）、锡（Sn）、锑（Sb）、铯（Cs）、钡（Ba）、铕（Eu）、铅（Pb）、钍（Th）、铀（U）；
2. 采用动态反应池（dynamic reaction cell，DRC）模式、以氨气（NH3）作为反应气，检测钾（K）、钙（Ca）、钒（V）、铬（Cr）、锰（Mn）、铁（Fe）；
3. 采用DRC模式、以氧气（O2）作为反应气，检测磷（P）与硒（Se）。

针对氯化物（Cl-）浓度较高的样品，采用DRC模式（以氧气O2为反应气）分析砷浓度，以规避氯化物的干扰。所有样品均采用2%（体积分数）超纯硝酸与电阻率为18.2兆欧·厘米的Milli-Q水配制并稀释，且经过严格的质量保证与质量控制（QA/QC）流程分析。

本数据包包含：
1. 压缩文件cation_data_2014-2021.zip，内含总计4517个文件：其中4516个为劳伦斯伯克利国家实验室（Lawrence Berkeley National Laboratory，LBNL）流域功能科学重点区域（SFA）各采样点的阳离子数据.csv文件，另有1个locations.csv文件，记录各采样点的经纬度信息；
2. 文件级元数据文件flmd.csv，列出数据集内所有文件及其关联元数据；
3. 数据字典文件dd.csv，包含所有文件中使用的术语/列标题，及其定义、单位与数据类型。
本数据集共计99个采样点位，包含同位素数据。

2021年4月11日更新：新增ICP-MS方法检出限（Method Detection Limits，MDLs）测定文档，可通过PDF或Microsoft Word格式获取。
2022年6月10日更新：对本数据集进行版本化更新，具体变更如下：
(1) 更新所有采样点位至2021年12月31日的阳离子数据；
(2) 移除数据文件列标题中的单位标注；
(3) 在标题行下方新增一行，用于标注各变量的单位；
(4) 移除两个变量的前后缀："aqberylliumion_asberyllium"与"aqlithiumion_aslithium"；
(5) 对空数值单元格填充-9999；
(6) 新增文件级元数据文件flmd.csv与数据字典文件dd.csv，以符合文件级元数据报告格式要求。
2022年9月9日更新：对报告格式相关文件（文件级元数据与数据字典）进行更新，具体包括：修正文件名互换错误，补充两个文件的元数据描述细节，新增header_row列以支持解析，且在文件名中加入版本号与日期（v2_20220909_flmd.csv与v2_20220909_dd.csv）。