Cloud point extraction-flame atomic absorption spectrometry for pre-concentration and determination of trace amounts of silver ions in water samples

In-situ formation of the adsorbent based on octadecylamine for the extraction of Ag+ ions from aqueous solutions and its determination by microinjection flame atomic absorption spectrometry

In this research, a dispersive solid phase extraction procedure based on changing the solubility of octadecylamine with pH was proposed to determine Ag+ ions in different water samples. For this purpose, first, the pH of sample solution containing the analyte was adjusted to 10.5. Then desired volume of the octadecylamine dissolved in acidic solution was injected into the solution. Because of the low solubility of octadecylamine in alkaline solution, a cloudy state was formed. The produced octadecylamine particles acted as a complexing agent for Ag+ ions and adsorbent for the formed complex. The obtained cloudy solution was centrifuged and the sedimented particles were removed and dissolved in a diluted nitric acid solution. It was injected into a flame atomic absorption spectrometry to determine the extracted amounts of the analyte. The effect of important parameters such as the amount of octadecylamine, volume of nitric acid, and centrifugation and vortexing conditions on the extraction efficiency of the procedure was studied and optimized. In optimal conditions, the developed method showed a linear range of 0.50-200 µg L-1. The limits of detection and quantification were 0.18 and 0.50 µg L-1, respectively. Extraction recovery was 93.6%. The relative standard deviations were less than 4%. The effectiveness of the method was investigated by determination of Ag+ ions in water and wastewater samples.

Recent Advances in Organic Sensors for the Detection of Ag+ Ions: A Comprehensive Review (2019-2023)

Recently, organic sensors for the detection of Ag+ and other metal ions have experienced significant advancements. This is because there is a growing demand for reliable and sensitive tools to monitor various environmental pollutants. Organic sensors have O-, S-, and N-donor atoms, which can act as a ligand and coordinate with different metal ions, hence stabilizing them in a variety of oxidation states. This interaction gives colorimetric and fluorescence changes, which are used to monitor Ag+ and other metal ions. This comprehensive review highlights the latest developments in organic sensors for the recognition of Ag+. We present an in-depth analysis of the underlying principles and mechanisms governing Ag+ ion recognition. Various organic sensing platforms, such as fluorescent and colorimetric sensors, are discussed, shedding light on their unique advantages and limitations. Special attention is given to the diverse range of organic ligands, receptors, and functional materials used to achieve high sensitivity, selectivity, and quantification accuracy. Additionally, we delve into real-world applications of organic sensors for Ag+ ion detection, examining their performance in complex matrices such as biological, environmental, industrial and agricultural matrices.

A Review of Analytical Techniques for the Determination and Separation of Silver Ions and Its Nanoparticles

Many articles have already been published dealing with silver ions and its nanoparticles, but mostly from the environmental and toxicological point of view. This article is a review focused on the various analytical techniques and detection platforms used in the separation and determination of mentioned above species, especially on the trace concentration level. Commonly used are optical methods because of their high sensitivity and easy automation. The separation methods are mainly used for the separation and preconcentration of silver particles. Their combination with other analytical techniques, mainly inductively coupled plasma mass spectrometry (ICP-MS) leads to very low detection limits of analysis. The electrochemical methods are also powerful and perspective mainly because of the fabrication of new sensors designed for silver determination. All methods may be combined with each other to achieve a synergistic improvement of analytical parameters with an impact on sensitivity, selectivity and reliability. The paper comprises a review of all three types of analytical methods on the determination of trace quantities of silver ions and its nanoparticles.

Ultrasound-Assisted One-Pot Cloud Point Extraction for Iron Determination Using Natural Chelating Ligands from Dipterocarpus intricatus Dyer Fruit

An ultrasound-assisted, one-pot cloud point extraction was developed for the determination of iron in vegetable samples by UV-Visible spectrophotometry. This method was based on the complexation of iron with an environmentally-friendly natural chelating agent extracted from Dipterocarpus intricatus Dyer fruit at pH 5.5 in the presence of Triton X-114. Reagent extraction, complexation, and preconcentration were performed simultaneously using ultrasound-assisted extraction at 45 °C. The surfactant-rich phase was diluted with ethanol and loaded through a syringe barrel packed with cotton that acted as a filter to trap the reagent powder. Analyte-entrapped on cotton was eluted using 0.1 mol·L⁻¹ nitric acid solution. Filtrate and eluate solutions were measured absorbance of the dark-blue product at 575 nm. Influential parameters for the procedure were investigated. Under the optimum experimental conditions, the calibration curve was linear, ranging from 0.1 to 1.0 mg·L⁻¹ with r² = 0.997. Limits of detection and quantification were 0.03 and 0.09 mg·L⁻¹, respectively while precision values of intra-day and inter-day were less than 5%. Recovery at 0.5 mg·L⁻¹ ranged from 89.0 to 99.8%, while iron content in vegetable samples ranged from 2.45 to 13.36 mg/100 g. This method was cost-effective, reliable, eco-friendly, and convenient as a green analytical approach to determining iron content.

Development a spectrofluorometric micellar supported encapsulated method for micro determination of silver ion using new 2,6-disubstituted pyridine derivatives

Herein, the presented manuscript provides for an extensive spectrofluorimetric method for micro determination of silver ion. This established method based on the use of the three synthesized 2,6-disubstituted pyridine derivatives (R1, R2 and R3) through exploiting their high fluorescence emission property. A noticeable effect on the fluorescence emission of the reagents after chelation with Ag (I) was monitored. Its noteworthy that the sensitivity and stability of this method was increased by using micellar medium. After chelation with Ag(I), the fluorescence emission of the ligands R1 and R2 were effectively quenched in a regular manner by increasing Ag(I) concentration. In contrast, an increase of the fluorescence intensity for reagent R3 after addition of Ag (I) was observed. The solvatochromism for all reagents under investigation was examined in different solvent. Furthermore, the chelation between Ag(I) and the and designed pyridine reagents was assessed spectrophotometrically. The optimum conditions for the most stable complexes which give a high signal difference were explored and well-determined. The linear range for determination of silver ion were determined and found to be 0.18-1.16, 0.06-0.59 and 0.18-1.43 μg mL^-1 for R1, R2 and R3, respectively. The statistical analytical parameters such as LOD, LOQ, SD of slope, SD of intercept and RDS were calculated. In addition, the developed methods were efficaciously applied for determination of Ag(I) in some water samples. These selective complexation methods found to be in good precision compared to official and reported method as revealed F-test.

Selective ionic liquid solvent bar micro-extraction for estimation of ultra-trace silver fractions in marine waters

Ag can be found in the ocean at the ultra-trace level, mainly as AgCl_n^(n-1)- and complexed by dissolved organic matter (Ag-DOM). However, methods for studying Ag speciation in marine waters are limited by the lack of extractants capable to separate organic and inorganic silver species in natural conditions of seawater samples. In this work, a two-phase solvent bar micro-extraction method using the ionic liquid trihexyltetradecylphosphonium chloride (Cyphos® 101) was applied for selective micro-extraction of AgCl_n^(n-1)- from organic silver in marine waters, working at seawater pH,. The application to real samples was performed under the following conditions: 2.5% Cyphos® 101 in kerosene solution with 10% dodecan-1-ol inside the fiber, and 30 min of sample extraction at a stirring rate of 800 rpm. The proposed SBME was successfully used for estimation of Ag fractions in waters from the Bay of Cádiz (South-west Spain) showing its applicability for a simple, fast and environmentally friendly speciation of silver in marine water samples. The method presented a linear response up to 500 ng L^-1 and a detection limit of 0.4 ng L^-1, using GF-AAS for instrumental determination.

Development of an efficient and sensitive analytical method for the determination of copper at trace levels by slotted quartz tube atomic absorption spectrometry after vortex-assisted dispersive liquid-liquid microextraction in biota and water samples using a novel ligand

This study describes the determination of trace levels of copper by slotted quartz tube atomic absorption spectrometry after dispersive liquid-liquid microextraction. A ligand synthesized from the reaction of salicylaldehyde and 1-naphthylamine was used to form coordinate copper complex prior to extraction. All parameters that influence the output of complex formation, extraction, and instrumental measurement were optimized to enhance the absorbance signal of copper. Under the optimum conditions, about 104-fold enhancement in sensitivity was recorded over the conventional flame atomic absorption spectrometer, corresponding to a 0.51 ng/mL detection limit. The percent relative standard deviation calculated for the lowest concentration (4.8%) indicated high precision for the experimental procedure. Accuracy and applicability of the optimum method were determined by performing spiked recovery tests on urine, lake water, and mineral water samples. Satisfactory recovery results were obtained between 82.2 and 106.3% at four different concentrations. Matrix matching method was also performed to increase the accuracy of quantification, and the percent recovery calculated for 175 ng/mL was 105.14%.