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Measurement and Determination of the Importance of Total Sulfhydryl Binding Site Concentrations in a Wide Range of Environmental Samples: A Novel UHPLC-MS Approach

测量和确定各种环境样品中总巯基结合位点浓度的重要性：一种新颖的 UHPLC-MS 方法

基本信息

批准号：
2149717
负责人：
Jeremy Fein
金额：
$ 52.35万
依托单位：
University of Notre Dame
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-05-01 至 2025-04-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2149717&HistoricalAwards=false
关键词：
Measurement Determination Importance Total Sulfhydryl

项目摘要

Heavy metal contamination of surface waters and groundwater systems affects water quality across the industrialized world, and the form in which heavy metals are present in these waters controls the environmental fate and bioavailability of these elements. The aqueous speciation of many metal contaminants is controlled by binding onto sulfur-based binding sites on bacteria and on dissolved organic matter. Despite the importance of these sulfur-based binding sites, very little is known about the abundance of the sites in natural waters or the processes that affect their abundance primarily due to analytical difficulties in measuring the concentration of these site types. In this study, we will use an analytical approach that we have developed for measuring sulfur-based binding sites both in water and sediment samples from a wide range of environments. The research will be transformative by providing baseline information that can be used to assess the importance of sulfur-based sites in controlling metal speciation and behavior in natural and human-impacted water systems. Furthermore, the ability to measure the sulfur-based binding site concentrations in aqueous samples and on environmental solid-phase surfaces at the sensitivity of our new approach enables the investigators to test several hypotheses about the role of these important sites in surface and near-surface water-rock systems. The sponsored research project will involve outreach and coordination with local high school science research programs in South Bend, Indiana schools. A geomicrobiology/environmental chemistry module will be created and taught in these high school science research programs (a short-course of 3-4 lectures and demonstrations), and 2-3 high school students will be recruited each year to conduct some of the sample analyses. Organic compounds with sulfhydryl metal-binding sites are ubiquitous in natural and engineered surface water, groundwater, and soil settings, yet the role that they play in controlling the environmental behavior and fate of metals is poorly understood due to the difficulty of measuring their concentrations in aqueous and solid samples. Although other binding site types are typically more abundant, sulfhydryl sites likely control the fate, transport, and bioavailability of chalcophile elements in the environment due to the much higher binding affinities that these elements have with sulfhydryl sites compared to with other binding site types. A first step in determining the role of organo-sulfhydryl binding sites in controlling metal speciation and bioavailability in natural systems is to measure the total concentration of these site types in surface and groundwaters and on environmental surfaces. Total sulfhydryl site concentrations in natural waters are likely to be, typically, in the nM to μM range, but sulfhydryl sites at these concentrations are not directly detectable using current approaches. In this study, the investigators will use a novel ultra-high performance liquid chromatography – mass spectrometry (UHPLC-MS) analytical approach that they have developed and tested for measuring total sulfhydryl site concentrations in aqueous and solid-phase samples, and conduct a survey of sulfhydryl site concentrations in a wide range of environments. The UHPLC-MS approach dramatically lowers the detection limit relative to previous analytical methods, measuring the total sulfhydryl site concentration in a sample indirectly by measuring the change in concentration, upon exposure to sulfhydryl sites, of a molecule that binds specifically and essentially irreversibly to sulfhydryl sites on aqueous molecules or solid phase surfaces. Because the concentration of the sulfhydryl-binding molecule can be determined very precisely using UHPLC-MS, the analytical approach has the potential to lower the detection limit for total sulfhydryl site concentration measurements by 2-3 orders of magnitude over current state-of-the-art techniques and to obtain detection limits of approximately 10 nM. The research team will use this approach to test several hypotheses about the role and occurrence of sulfhydryl sites in lake systems and on soil, microbiological, and root systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

地表沃茨和地下水系统的重金属污染影响工业化世界的水质，重金属在这些沃茨中的存在形式控制着这些元素的环境命运和生物利用度。许多金属污染物的水溶液形态通过结合到细菌和溶解的有机物上的硫基结合位点上来控制。尽管这些硫基结合位点的重要性，很少有人知道的网站在自然沃茨或影响其丰度的过程，主要是由于在测量这些网站类型的浓度分析困难的丰度。在这项研究中，我们将使用一种分析方法，我们已经开发了测量水和沉积物样品中的硫基结合位点从广泛的环境。该研究将通过提供可用于评估硫基站点在控制自然和人类影响的水系统中的金属形态和行为方面的重要性的基线信息来进行变革。此外，在我们的新方法的灵敏度下测量含水样品中和环境固相表面上的硫基结合位点浓度的能力使研究人员能够测试关于这些重要位点在表面和近表面水岩系统中的作用的几种假设。赞助的研究项目将涉及外展和协调与当地高中科学研究计划在南本德，印第安纳州学校。将在这些高中科学研究计划中创建和教授地球微生物学/环境化学模块（3-4个讲座和演示的短期课程），每年将招募2-3名高中生进行一些样品分析。具有巯基金属结合位点的有机化合物普遍存在于自然和工程地表水、地下水和土壤环境中，但由于难以测量其在水溶液和固体样品中的浓度，因此对它们在控制金属的环境行为和归宿方面所起的作用知之甚少。虽然其他结合位点类型通常更丰富，但巯基位点可能控制环境中亲硫元素的命运、运输和生物利用度，因为这些元素与巯基位点的结合亲和力比与其他结合位点类型高得多。确定有机巯基结合位点在控制自然系统中金属形态和生物利用率方面的作用的第一步是测量这些位点类型在地表水和地下水以及环境表面上的总浓度。天然沃茨中的总巯基位点浓度通常可能在nM至μM范围内，但使用目前的方法无法直接检测到这些浓度下的巯基位点。在这项研究中，研究人员将使用一种新的超高效液相色谱-质谱（UHPLC-MS）分析方法，他们已经开发和测试用于测量水相和固相样品中的总巯基位点浓度，并在广泛的环境中进行巯基位点浓度的调查。相对于先前的分析方法，UHPLC-MS方法显著降低了检测限，通过测量在暴露于巯基位点时特异性且基本上不可逆地结合到水性分子或固相表面上的巯基位点的分子的浓度变化来间接测量样品中的总巯基位点浓度。由于可以使用UHPLC-MS非常精确地测定巯基结合分子的浓度，因此该分析方法有可能将总巯基位点浓度测量的检测限降低2-3个数量级，并获得约10 nM的检测限。该研究小组将使用这种方法来测试几个假设的作用和发生的巯基网站在湖泊系统和土壤，微生物，和rootsystem.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。