Large volumes of seawater were sampled in the Gulf of Trieste (northern Adriatic Sea) in order to study the interactions between colloidal organic matter (COM) and metal(loid)s (Me) in coastal waters. COM (> 5 kDa) was isolated by ultrafiltration and characterized using ¹H NMR spectroscopy and elemental C_org. and N_tot. analyses. COM in the gulf represents about one quarter of the dissolved organic carbon (DOC), and according to ¹H NMR analysis, it is composed of polysaccharides (30–45%), lipids (30–55%), proteins and carboxyl-rich alicyclic molecules (CRAM) (15–20%), and humics (< 1%). An accumulation of COM was observed in the late spring–early summer. The polysaccharide and lipid fractions increased up to twofold and the protein fraction decreased, reflected in a higher C_org./N_tot. (28, molar) ratio. Higher concentrations of humics were observed due to local freshwater discharges in spring. COM from the Isonzo/Soča River differed from the marine COM exhibiting higher protein/CRAM and higher humic contents. COM from the Isonzo/Soča mouth at salinities 16–33 was compositionally similar to marine COM. Analysis of Me, performed by ICP-MS and CVAFS (Hg), showed that Hg (nearly 100%), Cu (20%), Cr (10%), and Se (10%) have the highest Me affinity to colloids. Similar to COM, Hg and Cu rapidly increased till summer due to their sequestration in accumulated COM (transfer to particulate phase). The observed Me/C_org. ratios (Co, Cd, Hg < U, Cr, Ni, Mn < As, Zn, Cu, V < Se, Al, Fe) differ somewhat from those of the Irving–Williams series and can be explained by the composition of COM and variable background concentrations of studied Me in the northern Adriatic. Data from the salinity gradient in the metal-contaminated (especially Hg, Pb, Zn) Isonzo/Soča mouth showed flocculation of Al and Ba and desorption of V, Co, As, Se, Cs, U, and Hg, from the riverine particles with increasing ionic strength, while Fe, Mn, Cu, Cr, Ni, Zn, Cd, and Pb did not correlate with salinity.

中文翻译：

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沿海水体中的胶体有机质和金属（胶体）（亚得里亚海北部的里雅斯特湾）

为了研究沿海水域中的胶体有机质（COM）和金属（类）（Me）之间的相互作用，在的里雅斯特湾（北亚得里亚海）中抽取了大量海水。通过超滤分离COM（> 5 kDa），并使用¹ H NMR光谱和元素C _org进行表征。和N _tot。分析。海湾中的COM约占溶解有机碳（DOC）的四分之一，根据¹1 H NMR分析由多糖（30–45％），脂质（30–55％），蛋白质和富含羧基的脂环族分子（CRAM）（15–20％）和腐殖质（<1％）组成。在春末夏初观察到COM的积累。多糖和脂质部分增加了两倍，而蛋白质部分减少了，这反映在较高的C _org上。/ N_总吨。（28，摩尔）比。由于春季局部淡水排放，观察到较高的腐殖质浓度。来自Isonzo /Soča河的COM与海洋COM不同，其具有更高的蛋白质/ CRAM和更高的腐殖质含量。来自Isonzo /Soča口的盐度为16-33的COM的成分与海洋COM相似。通过ICP-MS和CVAFS（Hg）对Me进行的分析表明，Hg（接近100％），Cu（20％），Cr（10％）和Se（10％）对胶体的Me亲和性最高。与COM相似，Hg和Cu直到夏季由于其固存在COM中（转移到颗粒相）而迅速增加。观察到的Me / C _org。比率（Co，Cd，Hg <U，Cr，Ni，Mn <As，Zn，Cu，V <Se，Al，Fe）与Irving–Williams系列的比率有所不同，可以用COM和亚得里亚海北部研究过的Me的不同背景浓度。来自金属污染（特别是Hg，Pb，Zn）Isonzo /Soča口中盐度梯度的数据显示，Al和Ba发生絮凝，V，Co，As，Se，Cs，U和Hg从河粉中解吸随着离子强度的增加，Fe，Mn，Cu，Cr，Ni，Zn，Cd和Pb与盐度无关。