Stabilization and determination of traces of silver in waters

Experimental Platform to Study Heavy Metal Ion−Enzyme Interactions and Amperometric Inhibitive Assay of Ag+Based on Solution State and Immobilized Glucose Oxidase

“…[18][19][20][21] It is regulated by WHO that the standard safe concentration of Ag þ for human is <0.05 ppm. 22 The Environmental Protection Agency (EPA) approves certification of silver as a pesticide (EPA 73499-2) and limits the discharge concentration of soluble silver to 5 ppm. 23 Considerable efforts have been devoted to the development of chemosensors and biosensors for the Ag þ assay, since the sensor methods have the application capability of dynamic, online, and in-field quantitative monitoring of the target analyte.…”

“…The annual release of silver to the environment is estimated to be as high as 2500 tons . The wide utilization of silver and its compounds in industries (e.g., electronics, photography, and mirrors) and the relatively high toxicity of Ag + highly call for the sensitive determination of Ag + . − It is regulated by WHO that the standard safe concentration of Ag + for human is <0.05 ppm . The Environmental Protection Agency (EPA) approves certification of silver as a pesticide (EPA 73499-2) and limits the discharge concentration of soluble silver to 5 ppm .…”

Analyte-triggered in situ “off–on” of Tyndall effect for smartphone-based quantitative nanosensing of Ag+ ions

“…The second TEA is then proposed to further reduce the LOD down to ~ 78 nM (3σ) using the oxidizability of Ag + towards 3,3′,5,5′-tetramethylbenzidine (TMB) molecules to produce positively-charged oxidized products (ox-TMB) that allow for aggregation of negativelycharged plasmonic AuNP nanoprobes through electrostatic interactions leading to remarkably-amplified TE responses. Both the TEAs can meet the requirement of World Health Organization related to the minimum allowable limit of Ag + level in drinking water (460 nM) [34]. The two new methods are particularly suitable for point-of-need use.…”

Concentration of trace metals by solvent extraction and their determination by atomic absorption spectrophotometry

“…Solvent extraction techniques have proved to be very useful for preconcentration of traces of metal ions to the levels where they can be easily and accurately determined by atomic absorption (Mansell and Emmel, 1965;Mulford, 1966;Sachdev, Robinson, et al, 1967;Slavin, 1964;West, West, et al, 1967). Various complexing agents such as diphenylthiocarbazone(dithizone), dithiocarbamate, cupferron, and 8-quinolinol(oxine), can be used for the extraction of a large variety of metal ions.…”

“…Conditions for extractions into solvents such as chloroform or carbon tetrachloride have already been reported (Morrison, 1957;Sandell, 1959), but chlorinated solvents are undesirable for atomic absorption methods because of the use of flame for atomization. Recently, the extraction of silver into ethyl propionate containing dithizone was reported (West, West, et al, 1967). The silver-dithizone complex was found to be stable in ethyl propionate for several days.…”