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  • 1
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract An investigation is conducted on the status of trace and minor elements in some foodstuffs (cereals, vegetables, milk, egg and fish), commonly consumed in Bangladesh, using proton induced X-ray emission (PIXE) and radioisotope-induced X-ray fluorescence (XRF) techniques. In PIXE measurements, the samples were irradiated in air with 2.0 MeV (energy on the target) protons having the beam intensity of 30 nA for characteristic X-ray excitation, while in XRF analysis, the samples were excited for 5000 seconds with a 10 mCi Cd-109 annular X-ray source. The elemental concentration of K, Ca, Mn, Fe, Ni, Cu, Zn, Se, As, Br, Rb, Sr, Mo, and Pb were determined in the samples by comparison with X-ray yield curves constructed from IAEA and NBS standard reference materials. The validity of the analytical procedures (PIXE and XRF) followed in this study has been confirmed by comparative measurements of Cu, Zn and Mn in some varieties of rice with atomic absorption spectrophotometry. The results indicate that none of the food regimes investigated here is burdened with heavy metals beyond permissible limits except five species of vegetables with chromium having the range of 0.99–3.59 mg/kg compared to the literature value of 0.0–0.36 mg/kg (dry weight basis). An average value of 0.2 mg/kg of arsenic was observed both in IRRI (n=16) and local Aman (n=12) varieties of rice and only one hen egg contained 1.7 mg/kg of lead in yolk. The zinc content in some marine fish from Bay of Bengal was reported to be 5.4–19.5 mg/kg, whereas in the present study of sweet-water fish, the level is found to be 15.2–62.1 mg/kg (fresh weight basis) for five species. In human milk, both Cu (0.12–0.25 mg/l, n=8) and Zn (0.28–1.80 mg/l, n=8) levels appear to be almost half the literature values (n=25). On the other hand formula milk has higher values of Cu (0.32–1.63 mg/kg, n=16) and Zn (5.16–19.8 mg/kg, n=16).
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1573-2932
    Keywords: anthropogenic sources ; deposition ; fossil fuels ; particulates ; precipitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract Precipitation was collected on an event basis from July 1994 to August 1995 at towns around the capital Dhaka of Bangladesh. The major chemical components were determined by atomic absorption spectrophotometry, UV-Visible spectrophotometry and ion selective electrode method. The concentrations of nitrate and sulphate were found to be below the minimum detection limit of 1.0 mg L- 1; the concentrations of Cl-, Na+, K+, Ca+2, Mg+2 and NH4+ ranged from 〈1.0–3.03, 0.14–1.70, 0.04–0.37, 0.04–1.30, 〈0.02–0.20 and 〈0.10–2.33 mg L-1, respectively. The values of pH and conductivity ranged from 4.80–6.74 and 3.3–37.5 μS cm-1, respectively.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 325 (1986), S. 168-170 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary The adsorption behaviour of ten metal complexes Cr(III), Cr(VI), Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) with ferron on Zeo-Karb-226 in the H+ form was investigated at eight different pH-values in order to develop a preconcentration technique for trace amounts of these elements in aqueous solution. The concentrations of the remaining unadsorbed metal ions were determined by atomic absorption spectrophotometry. Under the present experimental conditions, Cr(III) and Pb(II) can be quantitatively determined within the pH range 4–8, while for Cd(II), the optimum pH-range is 7–11. But at pH 11, more than 95% of Cu(II) and Co(II) can be extracted from aqueous solution. The suitability of the technique has been evaluated by analyzing cadmium in simulated water samples. The results indicate that as low as 5 μg 1−1 of CD can be recovered with more than 96% efficiency from 11 of simulated water solution.
    Notes: Zusammenfassung Das Adsorptionsverhalten der Komplexe von Cr(III), Cr(VI), Mn(II), Fe(II), Fe(III), Co(II), Ni(II), Cu(II), Cd(II) und Pb(II) mit Ferron an Zeokarb-226 in der H+-Form wurde bei acht verschiedenen pH-Werten untersucht, um eine Anreicherungsmethode für Spuren dieser Elemente zu entwickeln. Die Konzentrationen der verbliebenen nicht adsorbierten Metallionen wurden mit Hilfe der AAS bestimmt. Cr(III) und Pb(II) können im pH-Bereich 4–8 quantitativ erfaßt werden, während der optimale Bereich für Cd(II) bei pH 7–11 liegt. Bei pH 11 werden jedoch mehr als 95% Cu(II) und Co(II) aus der wäßrigen Lösung extrahiert. Der Nutzen des Verfahrens wurde durch Bestimmung von Cd(II) in simulierten Wasserproben erwiesen. Noch 5 μg/l Cd können zu mehr als 96% aus 11 Wasserprobe wiedergefunden werden.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of radioanalytical and nuclear chemistry 97 (1986), S. 113-122 
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract The proton particle induced X-ray emission (proton PIXE) technique has been employed to study the heavy element status (essential and toxic) in five different varieties of pulses commonly cultivated and consumed in Bangladesh. In this analysis, the samples were irradiated in air with 2 MeV protons having 30 nA beam intensity for characteristic X-ray excitation. For 40 μC irradiations, the concentration of ten elements (K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, and Rb) was determined by comparison with a calibration obtained from the NBS orchard leaf standard, SRM 1571. In a comparative study with atomic absorption spectrophotometric (AAS) measurements of some elements in lathyrus sativus, the data were found to be in good agreement. The results obtained from the present study are discussed and compared with available data.
    Type of Medium: Electronic Resource
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