Determination of total silver and silver species in coastal seawater by inductively-coupled plasma mass spectrometry after batch sorption experiments with Chelex-100 resin

Abstract

Sorption experiments in batch mode with Chelex-100 resin have been carried out for the determination of total Ag, labile and inert fractions in seawater from Ria de Vigo (NE Atlantic ocean) by inductively coupled plasma-mass spectrometry (ICP-MS). The method allows an accurate determination of the total Ag thus avoiding the effect of the saline matrix when direct determination by ICP-MS is performed. Similarly, the distribution patterns of Ag among species with different lability can be established in seawater as a function of pH. Species distribution and total Ag contents have been obtained in CRM CASS-4 (near shore seawater) and four coastal seawater samples. While the free silver ion concentration accounts for a significant fraction at low pH, the labile inorganic fraction is most important at natural pH (%8) in non-polluted seawater. The inert and labile organic fractions were the most relevant in polluted coastal seawater. Complexation mechanisms of silver were also investigated from the sorption curves of silver on Chelex-100 according to the Gibbs-Donnan model. Two complexes were formed, AgL and AgL 2 with the following intrinsic complexation constants log b ð1npÞ ¼ À2:11 and À 10.02, respectively. The formation of the complex AgL predominates up to pH 4 but is negligible due to chloride ions effect, while the complex AgL 2 predominates from pH 4.

Silver as Antibacterial Agent: Ion, Nanoparticle, and Metal

“…In saltwater, the presence of different ions leads to a complex equilibrium of various species and complexes (especially chloro and hydrogen sulfide complexes) 22. 23 Besides, humic acids24 and proteins25 can bind silver ions. This prevents a prediction of the solubility and requires suitable experiments to measure the silver concentration.…”

Thiophene aldehyde-diamino uracil Schiff base: A novel fluorescent probe for detection and quantification of cupric, silver and ferric ions

“…It is well known that Ag speciation in sea waters is dominated by AgCl x À complexes, thus marine organisms have some protection against the toxic Ag + ion, as well as hydrophobic organic complexes which cannot form due to intense competition by high Cl À ion concentrations. Whereas, in fresh waters and as a result of low Cl À levels, there is more opportunity for Ag + to both exist freely or to bind organic ligands or other inorganic anions in freshwater [70]. Complexation of metal ions with organic ligands to create hydrophilic complexes which remain in solution reduces metal toxicity, while complexation to form hydrophobic complexes capable of passive diffusion across cell membranes increases metal toxicity.…”

Characteristics of nutrient release from sediments under different flow conditions

“…Nutrient released from increased re-suspended particles significantly increased with flow velocity, as more particles re-suspended under higher flow velocity. Further, nutrient release from re-suspended particles was a kinematic processes governed by kinetic coefficients of particle release (k 1 ) [38]. Kinetic coefficient (k 1 ) means the distribution of particulate and dissolved form of nutrients.…”