Amino accelerators and antioxidants (AAL/Os) have become a suite of contaminants of emerging concern recently due to the accumulating evidence for their environmental occurrence and associated toxic potential. Nevertheless, data on sedimentary deposition of AAL/Os has remained scarce, particularly for regions beyond the North America. In the present study, we elucidated spatial distribution of fifteen AAL/Os and five AAO transformation products (AAOTPs) in seventy-seven sediments from the Dong Nai River System (DNRS), Vietnam. Total concentrations of AAL/Os (∑AAL/Os) ranged from 0.377 to 51.4 ng/g (median: 5.01 ng/g). 1,3-Diphenylguanidine and 4,4′-bis(1,1-dimethylbenzyl) diphenylamine were the two most prevalent congeners, both with detection frequencies >80%. Additionally, AAOTPs were quantifiable in 79% of the DNRS sediments with a median ∑AAOTPs at 2.19 ng/g, dominated by N, N′-diphenylbenzidine and 2-nitrodiphenylamine. Higher sediment-associated levels of AAL/Os and AAOTPs were spotted in downstream and the primary tributary of the DNRS compared to the upstream, implying their cumulative sedimentation towards the estuarine region. The distribution patterns of AAL/Os and AAOTPs across individual transects also demonstrated the influence of human activities (e.g., urbanization and agriculture), hydrodynamics, and decontamination by mangrove reserves. Meanwhile, characteristics of sediments, i.e., total organic carbon (TOC) content and grain sizes, exhibited significant correlations with the burdens of these compounds, indicating their preferential partitioning into the fine and TOC-rich matter. This research sheds light on environmental behavior of AAL/Os and AAOTPs beneath Asian aquatic system, and highlights the need for further evaluation of their impacts on the wildlife and public health.

氨基促进剂和抗氧化剂 (AAL/Os) 最近已成为一系列新出现的污染物，因为它们在环境中的发生和相关的潜在毒性的证据越来越多。然而，关于 AAL/Os 沉积的数据仍然很少，特别是对于北美以外的地区。在本研究中，我们阐明了越南同奈河系统 (DNRS) 的 77 种沉积物中 15 种 AAL/O 和 5 种 AAO 转化产物 (AAOTP) 的空间分布。AAL/Os (∑AAL/Os) 的总浓度范围为 0.377 至 51.4 ng/g（中值：5.01 ng/g）。1,3-二苯胍和 4,4'-双(1,1-二甲基苄基)二苯胺是两种最普遍的同系物，两者的检测频率都>80%。此外，AAOTP 在 79% 的 DNRS 沉积物中是可量化的，中值 ∑AAOTP 为 2.19 ng/g，主要是N、N'-二苯基联苯胺和2-硝基二苯胺。与上游相比，在下游和 DNRS 的主要支流中发现了更高的沉积物相关水平的 AAL/Os 和 AAOTPs，这意味着它们向河口区域的累积沉积。AAL/Os 和 AAOTPs 在各个横断面上的分布模式也表明了人类活动（例如，城市化和农业）、流体动力学和红树林保护区净化的影响。同时，沉积物的特征，即总有机碳 (TOC) 含量和粒度，与这些化合物的负荷显着相关，表明它们优先分配到细小和富含 TOC 的物质中。这项研究揭示了亚洲水生系统下 AAL/Os 和 AAOTPs 的环境行为，