Question

Describe in detail the extraction, separation, and detection of each of the following samples using any resources available to you. Please be aware that more than one trace analytical technique may be applicable.

Water samples taken downstream from an abandoned mine for Arsenic, Cadmium, and Lead

PLEASE CITE REFERENCES

Answer 1

ARSENIC

EXTRACTION

The solvent extraction technique is commonly used for the determination of organic arsenic compounds, especially in biological samples.In addition, extraction with water, or extraction with methanol/water followed by centrifugation and filtration,or extraction with chloroform/methanol/water andsonication are very powerful extraction media and often used extraction procedures. The total arsenic in different samples is usually extracted using the microwave extraction procedure.

SEPERATION AND DETECTION

Determination of arsenic is of the cardinal importance for water quality analysis.Adsorption is considered a relatively simple, efficient and low cost

removal technique, especially convenient for application in rural areas. A wide range of sorbent materials for aqueous arsenic removal is available nowadays: biological materials, mineral oxides, different soils, activated carbons and polymer resins.

Chemisorption filters made by the paper manufacture method and consisting of cellulose, cationic and anionic ion exchangers, activated carbon and a corresponding chemical agent were used as adsorbents for the removal of arsenic from water.Cu 2+ ions exhibited the most efficient removal. Activated carbon impregnated with metallic silver and copper is also a very powerful adsorbent for the removal of arsenic from water.

CADMIUM

In present paper, the solvent extraction processes for the extraction and recovery of hazardous metal cadmium from aqueous solutions associated with commonly metallic and non-metallic ions, such as sulfate, chloride, nitrate and phosphate.the extraction of cadmium(II) ions from acidic aqueous solutions using a stirred transfer cell-type emulsion liquid membrane (ELM) prepared by dissolving in kerosene, with D2EHPA (an alkylphosphoric acid) as mobile carrier and Span-80 as surfactant.

SEPERATION AND DETERMINATION

Spectrometric techniques for the analysis of trace cadmium have developed rapidly due to the increasing need for accurate measurements at extremely low levels of this element in diverse matrices.separation and preconcentration procedures, such as electrochemical deposition, precipitation, coprecipitation, solid phase extraction, liquid–liquid extraction (LLE) and cloud point extraction (CPE), and consider the features of the their application with several spectrometric techniques.A simple and selective method for the separation and preconcentration of cadmium in water samples based on solidified floating organic drop microextraction (SFODME) was developed.

LEAD

EXTRACTION

Lead is extracted from ores dug from under-ground mines. Of the more than 60 minerals that contain lead, only 3 galena, cerussite and anglesite are commercially viable. However, most deposits of these ores are not found alone but mixed with other minerals such as pyrite, marcasite, and zinc blende.The iron-reduction process for extracting lead from its ores,where the reductant iron was produced in-situ by the carbothermic reduction of iron-bearing material in the lead smelter itself.

SEPERATION AND DETECTION

This material was used in the development of a procedure for preconcentration of lead, with subsequent detection by flame atomic absorption spectrometry (FAAS). This material was used in the development of a procedure for preconcentration of lead, with subsequent detection by flame atomic absorption spectrometry (FAAS). . A notable advantage of the method is that the determination of Pb (II) is free from the interference of almost all cations and ions found in the environment and waste water samples. The method of solid-phase extraction on octadecyl-bonded silica membrane disks modified with a new S–N-containing Schiff base (bis-2-thiophenal propandiamine) (BTPD) followed by elution and atomic absorption spectrometric detection.