Determination of selenium in garlic (Allium sativum) and onion (Allium cepa) by electro thermal atomic absorption spectrometry

A separation/enrichment procedure has been developed for the determination of selenium in garlic and onion samples by electrothermal atomic absorption spectrometry (ET-AAS) as a slurry sampling after preconcentration with 3,3-diaminobenzidine (DAB) reagent on the activated carbon. The influences of pH, time, amount of carbon and complexing reagent were outlined. The effect of acids used in the digestion of samples was also studied and compared. Selenium level was found to be 0.024 mu g g(-1) for onion (n = 5; LOD - 0.5 mu g L-1; LOQ - 1.7 mu g L-1) and 0.015 Vg g(-1) for garlic (n = 5; LOD - 1.3 mu g L-1; LOQ - 3.3 mu g L-1). Three different samples of garlic were analyzed by ko-instrumental neutron activation analysis (k(0)-INAA) at the Jozef Stefan Institute (JSI). The data obtained by k(0)-INAA show that the content of selenium overlapped the results obtained by ET-AAS

Determination of trace Elements in Hematite’s Iron Reference Material JSS-804-1 using ko-INAA

Different trace elements in hematite’s iron ore reference material (JSS-804-1) were investigated using k0-instrumental neutron activation analysis (k0-INAA). To avoid the interference of iron as matrix elements, а method for its separation was applied. Namely, a liquid-liquid extraction procedure by diisopropyl ether (DIPE) in hydrochloric acid solution and determination of trace elements in the aqueous phase was undertaken. The k0-INAA method was applied to determine the content of the investigated elements thus making it possible to follow the distribution of 39 elements (with intermediate/medium and long half-lived radionuclides) in the studied referent material. An important advantage of the proposed method is the possibility to determine the content of several trace elements after Fe separation. Additionally, the elimination of the matrix element also lowered the detection limit for some trace elements compared to their corresponding values determined by k0-INAA and certified values for some elements

Iron Quadrangle, Brazil : elemental concentration determined by k0-instrumental neutron activation analysis. Part II: kale samples.

The objective of this study was to evaluate the influence of mining activity on elemental concentrations in kale grown around a mining area. Two sites studied are in the Iron Quadrangle, Minas Gerais, Brazil, considered one of the richest mineral-bearing regions in the world. One site is near mineral exploration activity and the other is an ecological area. A comparator site outside the Iron Quadrangle was also analyzed. This work focused on the determination of the elemental concentrations in kale applying the k0-instrumental neutron activation analysis. As the Brazilian legislation specifies values for soil only, the results for kale were compared to the literature values and it was found that the vegetable does not present any health risks

The 2021 IAEA software intercomparison for k₀-INAA

In order to establish the variation between results in mass fractions due to software implementation, as measured by the k0-method for INAA, the IAEA has organized a software intercomparison. A complete set of test spectra and associated information was assembled. Efficiency curves, neutron spectrum parameters, correction factors and mass fractions were calculated with the participating programs (k0-IPEN, k0-INRIM, k0-DALAT, k0-IAEA and KayWin) using identical peak areas. In this paper, we report on the observed discrepancies, causes, remedies and future software developments. The test data, as well as intermediate results and observed mass fractions of the certified reference material BCR-320R “channel sediment” are available through the IAEA on request. The variations in concentrations attributed to differences between the programs were initially found to be 5.6 and 7.9%, for certified and uncertified concentrations, respectively. After the certified concentrations had been made available to the participants and they had been allowed to improve their programs, the variations found were 2.7 and 3.4%, respectively. The main identified remaining causes of variation are differences in the procedures used for detector efficiency characterisation and neutron spectrum parameter determination.RID/KEWO/Kwaliteitszorg-IM

Could atmospheric carbon be driving sedimentation?

Purpose: The objective of this study was to provide insights into the most recent responses of sediments to climate change and their capability to sequester atmospheric carbon (C). Methods: Three sediment cores were collected, one from the western Black Sea, and two from the southern Adriatic Sea. Cores were extruded and sectioned into 1 cm or 0.5 cm intervals. Sections were frozen, weighed, freeze-dried, and then weighed again to obtain dry weights. Freeze-dried samples were dated by using lead 210 (210Pb) and cesium 137/ americium 241 (137Cs/241Am). Organic and inorganic C were determined by combustion. Particle size distribution was determined using a Beckman Coulter particle size analyzer (LS 13,320; Beckman Coulter Inc.). Mineralogical analyses were carried out by a Philips X’Pert powder diffractometer. Results: Sedimentation and organic and inorganic C accumulation rates increased with time in both the Black Sea and the Adriatic Sea. The increase in accumulation rates continued after the global introduction in the early 1970s of controls on the release of phosphorus (P) into the environment and despite the reduced sediment yield of major rivers (Po and Danube). Therefore, the increased accumulation of organic and inorganic C in the sediments cannot be assigned only to nutrient availability. Instead, we suggest that the increase in organic C is the consequence of the increase in atmospheric C, which has made more carbon dioxide (CO2) available to phytoplankton, thus enabling more efficient photosynthesis. This process known as CO2 fertilization may increase the organic C accumulation in sediments. Simultaneously, the increase of sea temperatures decreases the calcite solubility resulting in increases of the inorganic C accumulation. Conclusion: Our results suggest that long-term, general increases in accumulation rates of organic and inorganic C in sediments are the consequence of increases in atmospheric C. This shows that coastal sediments play an important role in C uptake and thus in regulating the Earth’s climate