Cadmium Extraction from Solutions by Solid-Phase and its Trace Determination (original) (raw)
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Indonesian Journal of Fundamental and Applied Chemistry
The Pre-concentration of Cd(II) in water samples was carried out by using column solid phase extraction DOWEX 50WX2 prior to flame atomic absorption spectrometry analyzed. The analytical parameters consist of pH, flow rate, volume of eluent and volume of sample were determined.The optimum conditions were obtained pH was 5, sample flow rate was 1 mL min−1, volume of eluent nitric acid 1N was 10 mL and sample volume was 50 mL. The optimum conditions obtained were used to determine the detection limit and the accuracy of the method using tap water samples. Determination of detection limit used tap water which contain Cd 0.001 mg L-1 and the accuracy (recovery,%R) with concentration of Cd 0.01 mg L-1. The detection limit was found 0.2697±0.0899 µg L− 1 (n=7) and accuracy (n=7) was 93±6%. The result showed the accuracy still meets the acceptance criteria for accuracy (70%-125%) and the RSD 6% is smaller than the Horwitz value of 20.8%. Based on the accuracy (R%) and % RSD values obtained...
Membranes, 2018
A supported liquid membrane is developed for the separation of Cd from either high in salinity or acidity aqueous media. The membrane consisted of a durapore (polyvinylidene difluoride) polymeric support impregnated with a 0.5 M Aliquat 336 solution in decaline. The effect of carrier concentration, organic solvent and feed and receiving solutions on the metal permeability is studied. This system allows the effective transport of trace levels of Cd through the formation of CdCl 4 2− , which is the predominant species responsible for the extraction process, in both NaCl and HCl solutions. The supported liquid membrane system in a hollow fibre configuration allows the enrichment and separation of trace levels of Cd from spiked seawater samples, facilitating the analytical determination of this toxic metal.
A synergistic, simple and selective spectrophotometric method has been developed for 1-(2', 4'dinitroaminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol [2', 4'-dinitro APTPT] as a novel chromogenic reagent. The proposed method is based on the synergistic extraction of cadmium(II) with 2', 4'dinitro APTPT (0.01 mol L -1 ) in presence of 0.5 mol L -1 pyridine to give orange red coloured ternary complex of a molar ratio 1:2:2 (M:L:Py) in the pH range 9.3 -9.7. It exhibits a maximum absorption of coloured complex at 425 nm in chloroform against the reagent blank and the absorbance remains stable for at least 20 h. The system obeys Beer's law in the concentration range 1.0 -12.5 µg mL -1 of cadmium(II) and optimum range of 2.5 -12.5 µg mL -1 of the metal as evaluated by Ringbom's plot. The molar absorptivity and Sandell's sensitivity of cadmium (II) -2', 4'-dinitro APTPT-pyridine complex (1:2:2) was established by Job's method, mole ratio method and slope ratio method. Interference of the foreign ions was investigated and use of suitable masking agent enhances the selectivity of the method. The proposed method is rapid, reproducible and successfully applied for the determination of cadmium(II) in binary and synthetic mixtures, alloys, thin films and tobacco sample. The results of the present study were compared with that of atomic absorption spectrophotometer to test the validity of the method.
Journal of Hazardous Materials, 2007
For the analysis of cadmium, the toxicity of spectroscopic methods is increasing because the measurement of the low level for detection of this element is done in various samples. This review studies the methods of separation and pre-concentration and analyzes spectroscopic methods for detecting cadmium in water samples. Considering the amount of trace cadmium ion in the analysis of aqueous samples, a suitable method should be used. From the past, chemists have been trying to find a solid phase to recover analytes from the water matrix. The experimental method of SPE is a standard method for the analysis of heavy metals such as cadmium ion in aqueous samples. Cadmium is known worldwide as a toxic metal. Therefore, it is often necessary to determine this element in environmental, biological, food and agricultural samples. However, analyses are difficult because the quantities of cadmium samples are relatively small, except for trace amounts. Measurements are made by flame atomic absorption spectrometry and inductively coupled plasma optical emission spectrometry.For this reason, several preconcentration methods for the determination of cadmium ion, including solid phase extraction, coprecipitation and cloud point extraction, has been reviewed.A brief history of using Solid-phase extraction in the analysis of cadmium ion in water samples is presented in this paper.
Fresenius' Journal of Analytical Chemistry, 1990
A fast and simple method for preconcentration of Ni 2＋ , Cd 2＋ , Pb 2＋ , Zn 2＋ , Cu 2＋ and Co 2＋ from natural water samples was developed. The metal ions were complexed with sodium diethyldithiocarbamate (Na-DDTC), then adsorbed onto octadecyl silica membrane disk, recovered and determined by FAAS. Extraction efficiency, influence of sample volume and eluent flow rates, effects of pH, amount of Na-DDTC, nature and amount of eluent for elution of metal ions from membrane disk, break through volume and limit of detection have been evaluated. The effect of foreign ions on the percent recovery of heavy metal ions has also been studied. The limit of detection of the proposed method for Ni 2＋ , Cd 2＋ , Pb 2＋ , Zn 2＋ , Cu 2＋ and Co 2＋ was found to be 2.03, 0.47, 3.13, 0.44, 1.24 and 2.05 ng•mL-1 , respectively. The proposed (DDTC) method has been successfully applied to the recovery and determination of heavy metal ions in different water samples.
Sorption-Spectroscopic Determination of Cadmium Ions
By immobilization of 1-(2-pyridylazo)-2-oxynaphthalene-3,6-sodium disulfate on a polymer sorbent of polyacrylonitrile type, a carrier was obtained for the determination of cadmium ions. The optimal conditions for immobilization and complexation were found. The data obtained were used to develop a method for the determination of cadmium ions in waters.
SPECTROPHOTOMETRIC DETERMINATION OF TOXIC ELEMENTS (CADMIUM) IN AQUEOUS MEDIA
Trace amount of toxic element (Cadmium) was determined by spectrophotometer method using 1, 2-dihydroxy anthraquinone-3-sulphonic acid, sodium salt. (Alizarin red S) as a new spectrophotometer reagent. Alizarin red S reacts in slightly acidic solution (0 005 0 05M H2SO4) with cadmium to give a deep greenish yellow chelate which has an absorption maximum at 422 nm. The reaction is instantaneous and absorbance remains stab le for over 24hrs. The average molar absorption coefficient and sandell's sensitivity were found to he 2 24 10 3 L mol 1 cm 1 and 20 ng cm 2 of Cd respectively. Linear calibration graphs were obtained for 0 1 40 g mL 1 of Cd. The stoichiometric composition of the chelate is 1 : 2 (Cd : Alizarin red S). Large excess of over 50 cations, anions, and some common complexing agents (e.g EDTA, oxalate, citrate phosphate, thio-urea, SCN) do not interfere in the determination. The method was successfully used in the determination of cadmium in Several Standard Reference Materials (alloys, steels and water) as well as in some environmental waters (In land and surface), biological samples (human blood and urine), soil samples and complex synthetic mixtures. The method has high precision and accuracy. (S = 0 01 for 0 5 g mL 1 .
PVC Membrane Selective Electrode for Determination of Cadmium(II) Ion in Chocolate Samples
Chinese Journal of Chemical Engineering, 2014
Benzil bis(carbohydrazone) (BBC) is prepared and explored as new N N Schiff's base, which plays the role of an excellent ion carrier in the construction of a Cd(II) ion membrane sensor. The tris(2-ethylhexyl) phosphate best performance corresponds to a membrane composition of 30% poly (vinyl chloride), 65% (TEHP), 3.5% BBC and 1.5% tetradodecyl-ammoniumtetrakis(4-chlorophenyl) borate (ETH 500). This sensor shows very good selectivity and sensitivity towards cadmium ion over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The effect of membrane composition, selectivity, pH and influence of additive on the response properties of electrode were investigated. The response mechanism was discussed in the view of UV-spectroscopy. The electrode exhibits a Nernstian behavior (with slope of 29.7 mV per decade) over a very wide concentration range from 1.0×10 −1 to 1.0×10 −8 mol•L −1 with a detection limit of 3.2×10 −8 mol•L −1. It shows relatively fast response time in whole concentration range (<8 s) and can be used for at least 10 weeks in the pH range of 2.0-9.0. The proposed sensor is successfully used for the determination of cadmium in different chocolate samples and as indicator electrode in titration with ethylene diamine tetraacetate (EDTA).
Food Chemistry, 2012
A modified selective, highly sensitive and accurate procedure for the determination of trace amounts of cadmium which reacts with 1-(2-benzothiazolylazo)-2-hydroxy-3-naphthoic acid (BTAHNA) to give a deep violet complex with high molar absorptivity (7.05 Â 10 6 L mol À1 cm À1 , 3.92 Â 10 7 L mol À1 cm À1 , 1.78 Â 10 8 L mol À1 cm À1 , and 4.10 Â 10 8 L mol À1 cm À1 ), fixed on a Dowex 1-X8 type anion-exchange resin for 10 mL, 100 mL, 500 mL, and 1000 mL, respectively. Calibration is linear over the range 0.2-3.5 lg L À1 with RSD of 61.14% (n = 10). The detection and quantification limits were calculated.
Review on solvent extraction of cadmium from various solutions
Hydrometallurgy, 2000
Cadmium has wide application in the manufacturing of alloys, batteries, pigments and metal plating. The solid and liquid waste is generated during the production and at the end of service life. The recovery and recycling of cadmium from these waste materials is necessary to gain the metal values and protect the environment from hazard. In hydrometallurgical processes, solvent extraction is an important process for the recovery of non-ferrous metals from different aqueous leach liquor and waste effluent/solutions. 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 have been reviewed. Different process parameters, viz. pH, organic- to -aqueous ratio, kinetics of extraction and stripping to establish the conditions required for the extraction of cadmium and formation of a complex in the organic phase from different solutions, have been reported. The studies show the possibility of extraction and separation of cadmium from different solutions containing other metallic ions using anionic, cationic, solvating or mixed extractants. However, further attempts are also being made to develop selective organic extractants to recover cadmium efficiently on a commercial scale. The findings of these studies are also reported.► SX is potential tool for separation/ purification of Cd from aq. solutions. ► Based on solution composition, the extractant or mixed extractants can be selected. ► Cyanex 302, Cyanex 923, PC 88A and D2EHPA are found effective. ► D2EHPA has commercial potential for extracting Cd from solution.