Capabilities of a portable X-ray tube-based analyzer were evaluated for screening foods, thin films, and ceramic glazes for
toxic elements. A beverage spiked with Cr, Cu, and As and cocoa powder spiked with As and Pb could easily be distinguished
from unadulterated products when analyzed through their original container walls. With calibration, results for thin films
and ceramic glazes yielded accurate Pb results. Limits of detection (LODs) were 0.2–15 and 15 μg cm−2, respectively, for Pb and Cd in thin films and about 2 μg cm−2 for Pb in glazes. With analysis times of 0.5–1 min, sensitivities and LODs were superior to those obtained with radioisotopic
X-ray fluorescence analysis.
Authors:M. Freitas, A. Pacheco, H. Anawar, I. Dionísio, H. Dung, N. Canha, A. Bettencourt, F. Henriques, C. Pinto-Gomes, and S. Capelo
This study has determined contamination levels in soils and plants from the São Domingos mining area, Portugal, by k0-INAA. Total concentrations of As, Sb, Cr, Hg, Cu, Zn and Fe in soils were very high, exceeding the maximum limits in Portuguese
legislation. Concentrations of toxic elements like As, Sb and Zn were highest in roots of Erica andevalensis, Juncus acutus, Agrostis castellana and Nicotiana glauca. Additionally, As, Br, Cr, Fe, Sb and Zn in all organs of most plants were above toxicity levels. Those species that accumulated
relatively high concentrations of toxic elements in roots (and tops) may be cultivated for phytostabilisation of similar areas.
We have examined the leachability of the toxic elements cadmium, arsenic, mercury, and selenium from solid wastes. The solid wastes studied are municipal incinerator ash, coal fly ash, hospital incinerator ash, raw sewage sludge, sewage incinerator bottom ash, and sewage incinerator lagoon ash (which is a combination of bottom and fly ashes). Cadmium displayed the greatest leachability in all waste types, with 76% leached from the municipal refuse incinerator ash. Although the sources of elements in the wastes are diverse, the leachability and hence the bioavailability in the incinerator ash appears mainly determined by the volatility of the element.
A radiochemical method for simultaneous determination of toxic elements (Hg, Cd and Sb) in biological materials has been developed. The procedure involves the irradiation of samples with thermal neutrons and quantitative one-step separation in 0.1M 4-(5-nonyl)pyridine/benzene from 2.0M hydrochloric acid followed by gamma-ray spectrometry. The procedure is applied for the analysis and to the studies of distribution of these elements in IAEA-RMs, human serum and hair samples. Results obtained are found to be in good agreement with those reported in the literature.
Authors:A. Mannan, S. Waheed, S. Ahmad, and I. Qureshi
Several potentially toxic trace elements, namely, Hg, Pb, Cd, As, Sb, Br and Se have been measured by INAA in combination with AAS techniques in the integrated diet representative of the inhabitants of Gujranwala, a highly industrialized city of Pakistan. The dietary intake values for these elements have been estimated from the prevailing concentration level in the summer and winter season diets, which reveals that present intake data are well within the reported WHO values and can be considered to be safe. Posslble sources of food contamination by the toxic elements and their adverse impacts on human heaith are briefly discussed.
Tracer packet, a group of carrier-free radioactive isotopes of few elements which are produced together with an objective to study some particular physical, chemical or biological systems is a new conception over the century old tracer technique and a decade old multitracer technique. This paper describes the production of a tracer packet of heavy and toxic metals containing carrier-free radionuclides of some heavy and toxic elements like mercury, thallium, lead, bismuth and polonium produced by medium energy 7Li and 12C irradiation on gold target and subsequent separation of bulk gold from the carrier-free products.
The concentration of 15 elements in various brands of cigarette tobacco and cigarette wrapping paper were determined using
instrumental neutron activation analysis. The paper of some of the brands contains higher concentrations of toxic elements
than the tobacco. The cigarette filter and the ash were also analyzed to determine the adsorption of toxic elements on the
filter and their transference in smoke. The toxic effects of some of the elements have been briefly discussed.
The ion-exchange selectivities for oxoanions of some toxic elements and halogens were studies on an amorphous hydrous titanium dioxide (Am-HTDO) as a function of OH– and anion concentrations in chloride and nitrate media. The adsorption isotherm was of the Langmuir type. The selectivity sequence increased in the order of ClO
was efficiently separated from ClO
were selectively separated from seawater. Such high selectivity of Am-HTDO may provide a new concentration technique of these toxic elements in environmental materials.
Authors:A. Garg, R. Paul Choudhury, R. Acharya, and A. Reddy
Tobacco smoking/chewing has been a cause of concern because of it being related with oral cancer. It causes stimulation and
ill physiological effects. Ten different brands of spit tobacco, eight gutkaas and five paan masalas have been analyzed for
seven minor (Al, Na, K, Ca, Cl, Mg, and P) and 17 trace (As, Ba, Br, Co, Cr, Cs, Cu, Eu, Fe, Hg, La, Mn, Rb, Sb, Sc, Th, and
Zn) elements by instrumental neutron activation analysis. Also Ni and Pb were determined by atomic absorption spectrophotometry.
Concentration of Cd was below detection limit (<10 mg kg−1) in the tobacco samples. Mg, generally added as MgCO3 to prevent caking, is present as minor constituent in spit tobacco and gutkaas but is below detection limit (<1 g kg−1) in paan masalas. Most elemental concentrations vary in a wide range depending on the nature of chewing tobacco. Spit tobacco
has been found to be more enriched in essential elements (Ca, K, Na, P, Mn, and Rb), whereas gutkaas contain higher concentrations
of Fe, Cr, Cu, and Zn. Paan masalas contain lower contents of other elements but higher content of Hg. Gutkaas also contain
higher amounts of As and Pb. Further glutamic acid has been separated from tobacco leaves and characterized as it might bind
with some elements.
Twenty different brands of Chinese tea were analyzed for multiple trace elements, including some essential and toxic elements,
by neutron activation analysis (NAA). A comparison among tea brands from China, India, US and other countries was made for
the ranges and averages of concentrations for Na, K, Mn, Cu, and Br. It has been observed that the trace element contents
in tea leaves are largely dependent upon the soil and the environment where the tea grows. Chinese tea is rich in Mn and Cu
comparing with those of other counties surveyed, but is indigent in Na. The transference ratio for each element determined
(i.e., the fraction of an element in tea leave transferred into solution when tea is leached by percolation) is also reported.
Adult daily intakes of some essential and toxic elements from tea drinking were also estimated.