Atmospheric Hg isotope and concentration data in Terengganu, Malaysia

This dataset contains the isotopic compositions of atmospheric gaseous elemental mercury in Terengganu, Malaysia.Methods1. Sample Collection: Two sampling sites, one inside the Universiti Malaysia Terengganu (M1, 103.088°E, 5.408°N, 0 m) and another inside the Polytechnic of Kuala Terengganu (M2, 103.136°E, 5.330°N, 0 m) were chosen for GEM sampling. GEM samples were collected continuously using chlorine-impregnated activated carbon (CLC, 0.5 g) traps at a 10-day time resolution from December 2019 to January 2021.2. Preconcentration and Determination of GEM: GEM collected on CLC traps was thermally desorbed into 5 mL of mixed acid trapping solution (40%, 2HNO3/1HCl, v/v) (K Li et al., 2019) and Hg concentration in the trapping solution was then measured using a cold vapor atomic fluorescence spectroscopy (CVAFS). GEM concentration in each GEM sample was calculated by dividing total Hg mass (ng) detected in the trapping solution by the sampling air volume.3. Hg Isotope Analysis: Isotope ratios of GEM were measured by MC-ICPMS (Nu II, Instruments, U.K.) at the State key Laboratory of Environmental Geochemistry, CAS (Guiyang, China). MDF signatures of GEM are reported using delta notation (δ) and calculated as follows:δxxxHgGEM = [ (xxxHg / 198Hg) GEM/ (xxxHg / 198Hg) NIST 3133 − 1] × 1000‰ (1)where δxxxHgGEM represents the MDF signatures of GEM in per mil (‰), and xxx refers to the mass number of Hg isotopes (199, 200, 201, 202, and 204). The MIF signatures of GEM are expressed using the capital delta notation (Δ) and calculated based on the Kinetic MDF law as follows:ΔxxxHgGEM = δxxxHgGEM − βxxx × δ202HgGEM (2)where ΔxxxHgGEM represents the MIF signatures of GEM in per mil (‰), and βxxx are 0.252, 0.5024, 0.752, and 1.493 for 199Hg, 200Hg, 201Hg, and 204Hg, respectively.In this study, when the 2sd values of GEM isotopic compositions were lower than the procedural RM 8610, 2sd values of the procedural RM 8610 were used to represent the 2sd of GEM isotopic compositions.本数据集收录了马来西亚登嘉楼地区大气气态元素汞（gaseous elemental mercury, GEM）的同位素组成。 1. 样品采集：选取两个采样点位，一处位于马来西亚登嘉楼大学校园内（M1，103.088°E，5.408°N，海拔0 m），另一处位于瓜拉登嘉楼理工学院校园内（M2，103.136°E，5.330°N，海拔0 m），用于GEM采样。于2019年12月至2021年1月期间，采用浸渍氯活性炭（chlorine-impregnated activated carbon, CLC，0.5 g）捕集阱以10天的时间分辨率连续采集GEM样品。 2. GEM的预富集与测定：将CLC捕集阱上采集的GEM热脱附至5 mL体积分数为40%的2份硝酸与1份盐酸的混合酸捕集液（v/v）（K Li等，2019）中，随后采用冷蒸气原子荧光光谱法（cold vapor atomic fluorescence spectroscopy, CVAFS）测定捕集液中的汞浓度。通过将捕集液中检测到的总汞质量（ng）除以采样空气体积，计算得到每份GEM样品中的GEM浓度。 3. 汞同位素分析：在中国科学院环境地球化学国家重点实验室（中国贵阳），借助英国Nu Instruments公司生产的Nu II型多接收电感耦合等离子体质谱（MC-ICPMS）测定GEM的同位素比值。GEM的质量依赖分馏（mass-dependent fractionation, MDF）特征采用δ标记法（δ）表征，计算公式如下： δ^xxxHg_GEM = [(^xxxHg/¹⁹⁸Hg)_GEM / (^xxxHg/¹⁹⁸Hg)_{NIST 3133} − 1] × 1000‰ (1) 其中，δ^xxxHg_GEM表示以千分比（‰）为单位的GEM MDF特征，xxx代表汞同位素的质量数（199、200、201、202和204）。GEM的质量无关分馏（mass-independent fractionation, MIF）特征采用大写Δ标记法（Δ）表征，并基于动力学MDF定律计算得到，计算公式如下： Δ^xxxHg_GEM = δ^xxxHg_GEM − β_xxx × δ²⁰²Hg_GEM (2) 其中，Δ^xxxHg_GEM表示以千分比（‰）为单位的GEM MIF特征，针对¹⁹⁹Hg、²⁰⁰Hg、²⁰¹Hg和²⁰⁴Hg，β_xxx分别取值为0.252、0.5024、0.752和1.493。 本研究中，当GEM同位素组成的2sd值低于分析流程所用标准参考物质RM 8610的2sd值时，采用RM 8610的2sd值表征GEM同位素组成的标准偏差。

搜集汇总

背景与挑战

背景概述

该数据集提供了马来西亚登嘉楼地区大气气态元素汞（GEM）的同位素组成和浓度数据，采样时间为2019年12月至2021年1月，时间分辨率为10天，覆盖两个采样点。数据集采用氯浸渍活性碳捕集和冷蒸气原子荧光光谱法测定浓度，并使用MC-ICPMS技术进行汞同位素分析，重点关注稳定汞同位素、海洋汞排放和半球间梯度等研究主题。