Sampling Atomic Absorption Spectrometry Research Articles

Electrothermal atomic absorption spectrometry using an improved solid sampling system for the analysis of high purity tantalum powders

A solid sampling atomic absorption method for the determination of Cu, Fe, Mn, Na and Zn in high-purity tantalum powders has been developed. It is based on a direct automatic introduction of the sample into the graphite tube using the platform technique. Standard hollow-cathode lamps in combination with deuterium background correction are used as radiation sources. This and some additional modifications of the Grün spectrometer hard- and software lead to a significant improvement of its performance. With the maximum applicable sample mass of 40 mg limits of detection of 1 ng g −1, 27 ng g −1, 1.5 ng g −1, 0.7 ng g −1 and 0.1 ng g −1, respectively, are achieved for Cu, Fe, Mn, Na and Zn. Aqueous standard solutions are used for calibration. Comparison of the results obtained by solid sampling atomic absorption spectrometry with those of the liquid sampling technique show satisfactory agreement.

Sources of error in direct solid sampling Zeeman atomic absorption spectrometry analyses of biological samples with high water content

Analytical errors were quantified in the direct analyses of trace elements in samples with high water content by means of solid sampling atomic absorption spectrometry with Zeeman effect background correction (direct SS-ZAAS). Time versus mass curves for HNO 3 (0.1 mol 1 −1), blood, kidney and liver at different temperatures (+20, +4, −20°C) and mass input (0.07 to 42 mg) were observed. Following a stabilization period, mass losses appeared to be nearly linear and independent of input mass. By means of a function using observed stabilization time and mass losses a 10% increase in analyte content was calculated as occurring at and below 0.06 mg. Experimentally, 10% increases were found to occur within a range 0–0.07 mg for weighed Cd solutions (0.1 and 0.2 ng mg −1 in 0.1 mol 1 −1 HNO 3 at 5°C). An automated solid sampling system consisting of microbalance, dispenser, transport system and electronics was integrated in the experiments. Manual working time and the necessity of operator presence were reduced by at least 80%. Performance and capacity compared well to the manual SS-ZAAS mode. Automated SS-ZAAS analysis in fresh animal tissues is proposed for use as a screening and reference method in official residue control.

Accumulation of manganese and copper in pallidum of cirrhotic patients: role in the pathogenesis of hepatic encephalopathy?

Concentrations of zinc, copper and manganese were measured by atomic absorption spectrometry in samples of globus pallidus obtained at autopsy from 9 patients with chronic liver disease and an equal number of age-matched controls. Manganese concentrations were significantly increased several fold (p < 0.01) in globus pallidus of liver disease patients accompanied by smaller but significant 2-fold increases of copper. Zinc concentrations, on the other hand, were within normal limits. Increased pallidal manganese offers a cogent explanation for the observed T1-weighted MRI signal hyperintensity in pallidum of cirrhotic patients. Increased copper content in brain suggests the existence of common pathophysiologic mechanisms in inherited (Wilson Disease) and acquired hepatocerebral disorders.

Packed glassy carbon tube atomizer for direct determinations by atomic absorption spectrometry, free from background absorption

An electrothermal atomizer consisting of a long glassy carbon tube packed with activated charcoal was evaluated for the direct determination of trace elements in biological materials by atomic absorption spectrometry, in the absence of any background absorption. The maximum temperature of the atomizer of 2280 °C was maintained continuously by an electric power supply of about 7 kW. Under such isothermal conditions, few chemical interferences and high accuracy (relative error <8%) and precision (RSO <3.5%) were obtained in the direct determination of trace elements (Cu, Mg and Mn) in National Institute of Standards and Technology biological Standard Reference Materials by solid sampling atomic absorption spectrometry.

A new preparation method of calibration graphs for direct analysis of powdered biological samples by solid sampling atomic absorption spectrometry. Standard addition method for solid sampling technique.

A new preparation method of calibration graphs for direct analysis of powdered biological samples by solid sampling atomic absorption spectrometry. Standard addition method for solid sampling technique.

Solid sampling atomic absorption spectrometry and matrix composition of organic reference materials

Abstract

Determination of calcium by atomic-absorption spectrometry in samples dissolved by acid mixtures

The effect of lanthanum addition to the fluoboric-boric acid matrix for the determination of calcium by atomic absorption spectrometry has been studied. The samples were decomposed in a pressure vessel. The addition of hydrochloric acid before lanthanum addition in the dissolved samples allowed the use of the air-acetylene flame, which gives more accurate data than the acetylene-nitrous flame and is easier to handle.

Cadmium and zinc concentrations in fetal and maternal rat tissue after parenteral administration of cadmium during pregnancy.

Cadmium (Cd) and zinc (Zn) concentrations were determined by solid sampling atomic absorption spectrometry (AAS) in rat maternal and fetal tissues after exposure to cadmium. Cadmium was administered subcutaneously as CdCl2 in saline daily during pregnancy. Two experiments were performed. In expt. I we investigated the tissue concentration at day 19 (gestational age) after administration of several doses: 0, 1.1, 2.2, 4.4, and 8.8 mumol Cd/kg/day. In expt. II the course of the Cd and Zn concentrations during pregnancy was investigated by collecting samples at days 14, 16, 18 and 20, after daily injections of 4.4 mumol Cd/kg. Cadmium concentrations in blood, maternal liver, placenta and fetal liver increased with dose and duration of exposure. Cadmium was heavily accumulated in the liver and transferred to the fetus only in small amounts. The zinc concentration in the maternal liver was positively correlated with the cadmium concentration. In the placenta the zinc concentration was not affected. Zinc in fetal liver was decreased from day 18 onward. Despite relatively high cadmium levels and decreased zinc levels in the fetus, we observed no adverse effects on various reproduction parameters, such as birth weights and obvious malformations.

Untersuchungen zur Bestimmung von Bi, Cd, Hg, Pb und Tl in hochreinem Gallium durch Graphitrohr-AAS bei Verdampfung fester Proben

Traces of Bi, Cd, Hg, Pb and Tl in the lower μ·g−1 range are determined by direct electrothermal atomic absorption spectrometry in samples of about 5 mg of metallic gallium (Sr about 0.1). Electrolytically spiked samples of high-purity gallium are used for calibration. For the analysis of high-purity gallium (7–8 N) the limit of detection of Bi, Hg and Pb can be simply improved for 2–3 orders of magnitude by previous partial dissolution of larger weighed samples in acid according to [2]. The accuracy of the analytical results was verified by ICP mass spectrometry.

Trace elements in whole blood of multiple sclerosis.

Fe, Zn, and Cu were determined by atomic absorption spectrometry in samples of whole blood after weighing and wet ashing with HNO3. 35 healthy persons were compared with 119 multiple sclerosis (MS) patients and 13 patients with other diseases of the CNS. The values from normal persons are in full agreement with those cited in the literature, men showing a significantly higher level of Fe than women, whereas for Zn and Cu there is no significant sex difference. In comparison with the reference group the patients show no difference at all for Fe and only a minor one for Cu, but Zn values are greatly increased in MS patients (by 25-75%). The increase is higher in the relapsing form of MS than in the chronic form, suggesting some connection with the activity of the disease. On the other hand, the duration of the illness and (implicitly) the age of the patient seem to be unimportant. As patients with other diseases of the CNS show a similar though somewhat smaller increase, we conclude that Zn elevation in whole blood is not a feature specific for MS. From the present results, however, we cannot decide if such deviations are causally connected with affections of the CNS or if they are only a concomitant manifestation.