Diffusive gradients in thin-films technique (DGT)

薄膜技术 ( DGT ) 中的扩散梯度
  • 文章类型: Journal Article
    应对准确监测水生系统中多环芳烃(PAHs)的挑战,这项研究采用薄膜(DGT)技术中的扩散梯度,通过原位预浓缩和时间积分浓度的测定,使方法的检出限低至0.02ngL-1至0.05ngL-1。在不同的环境条件下验证了开发的DGT采样器的功效,证明独立于pH(5.03-9.01)等因素,溶解的有机物(0-20mgL-1),和离子强度(0.0001-0.6M)。值得注意的是,引入一种新的理论方法来计算扩散系数的基础上的溶剂可及体积为PAHs定制显著增强了该方法的适用性,特别是对于溶解性低的有机污染物。在沿海地区的现场部署验证了DGT方法与传统的抓取采样,研究结果主张4至7天的最佳部署持续时间,以平衡敏感性并减轻滞后时间效应。这些结果提供了一个复杂的,有效解决水环境中疏水性有机污染物监测的持续挑战,扩大DGT在环境科学中的范围和适用性,并为研究人员提供强大的工具。
    Addressing the challenge of accurately monitoring polycyclic aromatic hydrocarbons (PAHs) in aquatic systems, this study employed diffusive gradients in thin-films (DGT) technique to achieve methods detection limits as low as 0.02 ng L-1 to 0.05 ng L-1 through in situ preconcentration and determination of time-integrated concentrations. The efficacy of the developed DGT samplers was validated under diverse environmental conditions, demonstrating independence from factors such as pH (5.03-9.01), dissolved organic matter (0-20 mg L-1), and ionic strength (0.0001-0.6 M). Notably, the introduction of a novel theoretical approach to calculate diffusion coefficients based on solvent-accessible volume tailored for PAHs significantly enhanced the method\'s applicability, particularly for organic pollutants with low solubility. Field deployments in coastal zones validated the DGT method against traditional grab sampling, with findings advocating a 4 to 7-day optimal deployment duration for balancing sensitivity and mitigating lag time effects. These results provide a sophisticated, efficient solution to the persistent challenge of monitoring hydrophobic organic pollutants in aquatic environments, broadening the scope and applicability of DGT in environmental science and providing a robust tool for researchers.
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  • 文章类型: Journal Article
    土壤中的重金属有可能被作物根部吸附,然后在作物中积累,当农作物被人类摄入时,最终会造成巨大的健康风险。因此,了解作物中重金属的富集模式具有一定的参考价值。薄膜中的扩散梯度(DGT)技术,作为一种原位被动采样方法,可用于评价土壤中重金属的生物可利用性。在这项研究中,通过DGT确定的土壤中生物可利用镉(Cd)的数据以及水稻和玉米籽粒中Cd的吸收,中国的浙江和广西是从WebofScience上以前的参考文献中收集的。通过比较生物富集因子,发现水稻和玉米中积累的重金属浓度遵循根>茎或叶>谷物的一般顺序。基于生物富集因子(BCF)和DGT法测定的生物可利用Cd含量,建立了玉米和水稻籽粒中Cd含量的准确、稳健预测模型,R2为0.986,均方根误差(RMSE)为0.128。这一结果表明,DGT方法可以预测作物对重金属的吸收。
    It is possible for heavy metals in soils to be adsorbed by crop roots and then accumulated in crops, which eventually causes great health risk when the crops are ingested by humans. Thus, it is valuable to understand the enrichment model of heavy metals in crops. Diffusive gradients in thin-films (DGT) technique, as an in-situ passive sampling method, can be used to evaluate the bioavailable heavy metals contents in soils. In this study, data of the bioavailable cadmium (Cd) in soils determined by DGT and Cd contents uptake in rice and maize grains in Tianjin, Zhejiang and Guangxi provinces of China were collected from previous references in Web of Science. By comparing bioconcentration factors, it was found that the heavy metal concentrations accumulated in rice and maize followed a general order roots > stems or leaves > grains. An accurate and robust model for the prediction of Cd content in maize and rice grains was established based on bioconcentration factor (BCF) and the bioavailable Cd content determined by DGT method, with R2 0.986 and root mean square error (RMSE) 0.128. This result suggests that the DGT method can be good tool for predicting heavy metals uptake in crops.
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