Determination of cadmium and lead in table salt by sequential multi-element flame atomic absorption spectrometry.
ABSTRACT In the present paper, a simultaneous pre-concentration procedure for the sequential determination of cadmium and lead in table salt samples using flame atomic absorption spectrometry is proposed. This method is based on the liquid-liquid extraction of cadmium(II) and lead(II) ions as dithizone complexes and direct aspiration of the organic phase for the spectrometer. The sequential determination of cadmium and lead is possible using a computer program. The optimization step was performed by a two-level fractional factorial design involving the variables: pH, dithizone mass, shaking time after addition of dithizone and shaking time after addition of solvent. In the studied levels these variables are not significant. The experimental conditions established propose a sample volume of 250mL and the extraction process using 4.0mL of methyl isobutyl ketone. This way, the procedure allows determination of cadmium and lead in table salt samples with a pre-concentration factor higher than 80, and detection limits of 0.3ngg(-1) for cadmium and 4.2ngg(-1) for lead. The precision expressed as relative standard deviation (n = 10) were 5.6 and 2.6% for cadmium concentration of 2 and 20ngg(-1), respectively, and of 3.2 and 1.1% for lead concentration of 20 and 200ngg(-1), respectively. Recoveries of cadmium and lead in several samples, measured by standard addition technique, proved also that this procedure is not affected by the matrix and can be applied satisfactorily for the determination of cadmium and lead in saline samples. The method was applied for the evaluation of the concentration of cadmium and lead in table salt samples consumed in Salvador City, Bahia, Brazil.
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ABSTRACT: Aims: In this study, the heavy metal contamination of consumable table salt, both unrefined and refined, was investigated. The provisional tolerable weekly intake (PTWI) of heavy metals just by edible salt, of the Isfahan population, was also estimated. Materials and Methods: Twenty samples of salt, including 15 refined and five unrefined were analyzed. Precision of the analysis was assured through repeated analysis of the five samples, which had a great demand in the city. The heavy metal content in the samples was analyzed with Flame Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma (ICP). The PTWI of the metals was calculated by a formula and by using the Iranian average body weight. Results: The mean and standard deviations of cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg), copper (Cu), and zinc (Zn), in refined table salts were 0.15 ± 0.02, 0.57 ± 0.1, 0.69 ± 0.09, 0.061 ± 0.008, 0.87 ± 0.11, and 6.34 ± 1.08 µg/g, and those in the unrefined ones were 0.16 ± 0.02, 0.61 ± 0.13, 0.63 ± 0.07, 0.058 ± 0.004, 0.86 ± 0.06, and 7.53 ± 2.93 µg/g, respectively. A PTWI via salt consumption was in the range of 0.8 – 3.1 percent. Conclusions: There was a significant difference between the heavy metal concentrations and their guideline values. Estimation of the health risk due to heavy metals was not possible as PTWI showed total intake of a metal by total food consumption during a week. Therefore, it was important to assess the public health risks arising from the presence of these toxic contaminants in the foods consumed by the population of Iran.IJEHE. 01/2013;
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ABSTRACT: We have developed a facile and highly sensitive sorbent for cadmium and lead ions. It is based on Fe(3)O(4) nanoparticles functionalized with a derivative of picoline and was characterized by scanning electron microscopy, differential thermographic analysis, and elemental analysis. The material can be applied to the preconcentration of lead and cadmium ions. Factors such as the type, concentration and volume of eluent, the pH of the sample solution, the time for extraction, and the volume of the sample were studied. The effects of a variety of ions on preconcentration and recovery of these ions were also investigated. The ions were determined by FAAS, and the limits of detection are <0.8 and <0.061 μg L(-1) for lead and cadmium, respectively. Recoveries and precisions are >98.0 % and <1.3 %, respectively. The method was validated by analyzing several certified leaf reference materials.Biological trace element research 06/2012; · 1.92 Impact Factor
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ABSTRACT: A method of separation and preconcentration for the determination of Zn, Cu, and Mn in natural water was described and real samples studied using flame atomic absorption spectrometry. The method is based on the adsorption of Mn2+, Cu2+ and Zn2+onto 3-((1H-Indol-3-yl)(3-nitrophenol)methyl)-1H indole (INMI) that is loaded onto Triton X-100-coated polyvinyl chloride. The effects of pH, reagent amount, sample volume and matrix of the sample on the sorption of metal ions were also investigated. Detection limits (3 SDb/m) of 1.9, 2.1 and 1.8 ng mL−1 for Cu2+, Zn2+ and Mn2+ along with a preconcentration factor of 270 for these ions were achieved. We demonstrated highly efficient solid phase extraction for the determination of analytes in complex matrices. The proposed procedure was applied to analyses of industrial, natural and waste water as well as to those of soil and fruit samples.ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 01/2011; 36(1):47-56. · 0.39 Impact Factor