Silver In Environmental Samples Research Articles

Determination of Silver in Environmental Samples by High-resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry after Preconcentration on Bentonite

Determination of Silver in Environmental Samples by High-resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry after Preconcentration on Bentonite

A Green Approach for Micro Determination of Silver(I) in Water and Soil Samples Using Vitamin C

A cloud point extraction/solvation method (CPE-SM) based on the use of vitamin C as a chelating agent was developed for the separation and determination of silver in environmental samples. TritonX-100 was used to extract silver ions in aqueous solutions after forming solvation species with vitamin C in the presence of salting-out (0.5 mol L-1 KNO3) at 90 C for 10 minutes. This study evaluated the main parameters affecting the CPE-SM method, such as the kind and concentration of the salting-out, organic reagents, silver ion, temperature, heating time, and volume of surfactant. Under the optimized experimental factors, the calibration curve was linear in the range (0.1 -10 μg/L). The relative standard deviation (RSD) was 1.1-2.9% for n:5 at 1,4,9 μg L-1, a low limit of detection (LOD), and a limit of quantification (LOQ) of 0.035, 0.116 μg L-1 respectively. The accuracy of the method was evaluated by two independent techniques (flame atomic absorption spectrometry – FAAS, and spectrophotometry - using dithizone as a complexing agent). The CPE-SM technique was used to preconcentrate and determine the silver ions in river water, tap water, and soil samples, and the results were favorable and good.

Separation and measurement of silver nanoparticles and silver ions using magnetic particles

The recent surge in consumer products and applications using metallic nanoparticles has increased the possibility of human or ecosystem exposure due to unintentional release into the environment. To protect consumer health and the environment, there is an urgent need to develop tools that can characterize and quantify these materials at low concentrations and in complex matrices. In this study, magnetic nanoparticles coated with either dopamine or glutathione were used to develop a new, simple and reliable method for the separation/pre-concentration of trace amounts of silver nanoparticles followed by their quantification using inductively coupled plasma mass spectrometry (ICP-MS). The structurally modified magnetic particles were able to capture trace amounts of silver nanoparticles (~2ppb) and concentrate (up to 250 times) the particles for analysis with ICP-MS. Under laboratory conditions, recovery of silver nanoparticles was >99%. More importantly, the magnetic particles selectively captured silver nanoparticles in a mixture containing both nano-particulate and ionic silver. This unique feature addresses the challenges of separation and quantification of silver nanoparticles in addition to the total silver in environmental samples. Spiking experiments showed recoveries higher than 97% for tap water and both fresh and saline surface water.

Determination of silver ion based on the redshift of emission wavelength of quantum dots functionalized with rhodanine

A simple and selective method for the determination of silver ions was developed by utilizing the red-shift in emission wavelength of the core–shell CdSe/CdS quantum dots (QDs) functionalized with rhodanine upon the addition of Ag+. A linear relationship was observed between the shift and the increase in concentration of Ag+ in the range of 0.0125–12.5 μmol/L. The mechanism of the red-shift was investigated and suggested that the coordination between Ag+ and rhodanine on the QDs surface caused an increase of particle size, which resulted in the red-shift of the QDs’ emission wavelength. A detection limit of 2 nmol/L was achieved. The developed method showed superior selectivity and was successfully applied to the determination of silver in environmental samples.

Determination of trace silver in environmental samples by room temperature ionic liquid-based preconcentration and flame atomic absorption spectrometry

We report on a new method for preconcentration of silver ion at trace level in environmental samples, and its subsequent determination by flame atomic absorption spectrometry (FAAS). The room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium hexafuorophosphate and the chelator 5-(4-dimethylaminobenzylidene)-rhodanine were used for extraction. Ag(I) was back-extracted from the organic phase into thiosulfate solution and then determined via FAAS. The effects of pH, concentration of chelating agent, extraction time and temperature, amounts of ionic liquid, ionic strength and potentially interfering ions were studied. Under optimized conditions, the enhancement factor is 30 was achieved. The detection limit (3 σ) is 0.28 ng mL−1, and the relative standard deviation is 4.1% for 7 replicate determinations at 5 ng mL−1 of Ag(I). The method was validated by analysis of certified reference materials and applied to the determination of Ag(I) in environmental samples with satisfactory results.

Determination of silver in environmental samples by tungsten wire preconcentration method–electrothermal atomic absorption spectrometry

A preconcentration method for silver in environmental waters involving adsorption on a tungsten wire, followed by electrothermal atomic absorption spectrometry with a tungsten tube atomizer is described. The optimal immersing time was 90 s. The best pH for the adsorption of silver was 3. Under the optimal conditions, the detection limit for silver by the tungsten wire preconcentration method was 5.0 ng l −1 (3S/N) and the relative standard deviation was 8.2%. The effects of large amounts of concomitants on the preconcentration of silver were evaluated. Even though 10 3- to 10 4-fold excess of matrix elements existed in water, the silver response was not significantly affected by the matrix elements. The method with preconcentration on a tungsten wire was applied to the determination of silver in waters and proved to be sensitive, simple, and convenient. This adsorption method can be utilized in in situ sampling of ultra-trace silver in environmental samples (waters). Furthermore, after sampling it is easy to carry and store the tungsten wire without contamination for a long time.