Atomic absorption spectrometric determination of cadmium and lead in human and artificial teeth by direct atomization technique

Determination of Trace Amounts of Lead Using the Flotation-spectrophotometric method

The present study describes a simple and highly selective method for separation, preconcentration and spectrophotometric determination of extremely low concentrations of lead. It is based on flotation of a complex of Pb2+ ions and Alizarin yellow between aqueous and n-hexane interface at pH = 6. The proposed procedure is also applied for determination of lead in both tap water and prepared sea water samples. Beer's Law was obeyed over the concentration range of 3.86 × 10-8 To 8.20 × 10-7 molL-1 (8-170 ngmL-1) with an apparent molar absorptivity of 1.33 × 106 molL-1 cm-1 for a 100 mL aliquot of the water sample. The detection limit (n = 10) was 8.7 × 10-9 molL-1 (1.0 ngmL-1) and the Relative standard deviation (R.S.D), (n = 10) for 7.2 × 10-7 molL-1 (150 ngmL-1) of Pb (II) was 4.36%. 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 determination of Pb (II) in tap and synthetic seawater samples was also carried out by the present method. The results were satisfactorily comparable so that the applicability of the proposed method was confirmed to the real samples.

Determination of Trace Amounts of Lead Using the Flotation-spectrophotometric method

The present study describes a simple and highly selective method for separation, preconcentration and spectrophotometric determination of extremely low concentrations of lead. It is based on flotation of a complex of Pb(2+) ions and Alizarin yellow between aqueous and n-hexane interface at pH = 6. The proposed procedure is also applied for determination of lead in both tap water and prepared sea water samples. Beer's Law was obeyed over the concentration range of 3.86 × 10(-8) To 8.20 × 10(-7) molL(-1) (8-170 ngmL(-1)) with an apparent molar absorptivity of 1.33 × 10(6) molL(-1) cm(-1) for a 100 mL aliquot of the water sample. The detection limit (n = 10) was 8.7 × 10(-9) molL(-1) (1.0 ngmL(-1)) and the Relative standard deviation (R.S.D), (n = 10) for 7.2 × 10(-7) molL(-1) (150 ngmL(-1)) of Pb (II) was 4.36%. 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 determination of Pb (II) in tap and synthetic seawater samples was also carried out by the present method. The results were satisfactorily comparable so that the applicability of the proposed method was confirmed to the real samples.

ICP/OES application for assessing cadmium uptake (or toxicity) in glomerular cells: influence of extracellular calcium

The risks of metals for health are highlighted by their chemical stability and their persistence in the environment. Chronic exposure to low cadmium (Cd) concentrations results in renal dysfunction mainly. Cd has been regarded primarily as a renal tubular toxicant, but glomerular structures may also be affected. Since the cellular environment may influence metal toxicity, differences concerning Cd uptake and toxicity were evaluated according to calcium (Ca) medium concentrations. An optimized inductively coupled plasma emission spectrometry method (ICP/OES) was developed under defined conditions, as a selective analytical tool to determine cadmium uptake in glomerular mesangial cells. The performance characteristics of the analytical system were evaluated for both Cd and Ca by calibration (50 to 250 microg/L and 1 to 5 mg/L), linearity (r2 .9968 and .9943), limits of detection (1 microg/L and 0.1 mg/L) and quantitation (3 microg/L and 0.3 mg/L), accuracy with spiking, and repeatability (1.2 and 2.9%) with matrix matched standards. Total intracellular Cd content was significantly threefold lower in 0.175 mM Ca medium (Ca-free Eagle's minimum essential medium [EMEM] medium with 5% fetal bovine serum [FBS]) than in EMEM medium (1.8 mM Ca) with respectively 0.16 and 0.37 microg/mg proteins after 24 h of Cd (1 microM) exposure. Similar differences were obtained in cytotoxicity studies with a fourfold reduction in the mortality index (IC50). Complementary assays using Ca-spiked medium reinforced that Cd cytotoxicity and uptake were significantly dependent on the concentration of extracellular Ca. These findings suggest direct link between Cd uptake and toxicity, underlining the relevance of the analytical method.

Slurry Sampling Techniques for the Determination of Lead in Bangladeshi Fish Samples by Electrothermal Atomic Absorption Spectrometry with a Metal Tube Atomizer

Ultrasonic slurry sampling electrothermal atomic absorption spectrometry with a metal tube atomizer has been applied to the determination of lead in Bangladeshi fish samples. The slurry sampling conditions, such as slurry stabilizing agent, slurry concentration, pyrolysis temperature for the slurried fish samples, particle size and ultrasonic agitation time, were optimized for electrothermal atomic absorption spectrometry with the Mo tube atomizer. Thiourea was used as the chemical modifier for the interference of matrix elements. The detection limit was 53 fg (3S/N). The determined amount of lead in Bangladeshi fish samples was consistent with those measured in the dissolved acid-digested samples. The advantages of the proposed methods are easy calibration, simplicity, low cost and rapid analysis.