Carbon thick sheet potentiometric sensor for selective determination of silver ions in X-ray photographic film

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.

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.

Exploitation of o-benzoyl benzoic acid as an efficient electroactive material for selective determination of Cr (III) ions in pharmaceutical samples and industrial waste water using carbon sensor

Herein, for the first time, o-benzoyl benzoic acid has been explored as a promising electroactive material for the fabrication of sensitive, precise and accurate carbon paste electrode (CPE) for selective detection of Cr (III) ion. o-benzoyl benzoic acid (o-BBA) as a sensing material and tricresylphosphate (TCP) as a solvent mediator improved the developed sensor performance to get the Nernstian cationic slope of 20.03 ± 0.11 mV decade^-1 within the concentration range of 5.0 × 10^-7-1.0 × 10^-1 mol L^-1. The sensor displayed a fast response time of 12 s reflecting a pH independency over the pH range of 3.1-4.7. Moreover, the reaction between the sensing material and Cr (III) ion on the developed sensor surface was elucidated using the microscopic technique such as scanning electron microscope (SEM) in addition to the energy dispersive X-ray analyzer (EDX). The proposed sensor showed an adequate shelf lifetime (∼33 days). The values of potentiometric selectivity coefficient were obtained by fixed interference and separate solution methods affirming a high distinguishing power of the fabricated sensor toward Cr (III) ions over the other interfering ions. The established sensor could be utilized with a promising success for the Cr (III) ion estimation in the industrial waste water and in the pharmaceutical forms. Additionally, it has been employed as a promising indicator sensor with a superior performance for potentiometric titration of Cr (III) ion against EDTA.