Rapid Determination of PCDDs, PCDFs and DL-PCBs in Foods, Feedingstuffs and Vegetable Oils Using New Modified Acid Silica
Issue:
Volume 8, Issue 1, March 2023
Pages:
1-15
Received:
2 December 2022
Accepted:
4 January 2023
Published:
9 June 2023
Abstract: Polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls are persistent organic pollutants (POPs), which in the recent years received huge attention due to their extreme stability, high potential toxicity and bioaccumulation in food chains. Main source of human exposure to these compounds is discovered in foods of animal origin, especially foods rich of fat. The target of the present study was to set up an analytical method for the determination of PCDDs/PCDFs and DL-PCB in vegetable oils, sunflower meals, sunflower seeds, rapeseeds and milk powder. The first step consisted of a semi-automatic Soxhlet extraction for 3 hours, by using a mixture of Hexane: Acetone - 80: 20, followed by acid digestion with 55% acid silica, and filtration. After concentration, the extract is purified on multilayer column (silica gel, silica-KOH, silica-H2SO4, anhydrous Na2SO4) followed by an alumina column separation in two fractions (first fraction containing PCDDs/PCDFs, and second containing only PCBs). The purified extract was then analyzed by GC/MS/MS. The newly developed approach in our lab was capable to reduce the overall time of sample preparation down to seven hours/per sample. Since the method shows good mean recoveries for all labelled congeners spiked in the samples (for PCDDs/PCDFs – 80-110%, for DL-PCBs – 70-85%), we assumed the absence of overestimation or underestimation in the analyzed samples.
Abstract: Polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls are persistent organic pollutants (POPs), which in the recent years received huge attention due to their extreme stability, high potential toxicity and bioaccumulation in food chains. Main source of human exposure to these compounds is discovered in foods of ...
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Soil Organic Carbon Sequestration in Finger Millet Production in Sub-Saharan Africa: A Review of Concepts and Practices
Joseph Ekwangu,
Susan Tumwebaze Balaba,
Twaha Ali Basamba Ateenyi,
John Steven Tenywa,
Helen Opie,
Deborah Lillian Nabirye,
Charles Andiku,
Owere Lawrence
Issue:
Volume 8, Issue 1, March 2023
Pages:
16-24
Received:
26 February 2023
Accepted:
25 April 2023
Published:
15 September 2023
Abstract: Soil has the capacity to sequester about 50-66% of the 42-78 Giga tons of carbon lost per year. However, the capacity of the soil to sequester carbon is dependent on soil texture and structure, rainfall, temperature, farming systems, and soil management practices. Management practices to enhance soil carbon sequestration include; cover cropping, nutrient management, woodland regeneration, no-till farming, manure, and sludge application, water conservation, and harvesting, efficient irrigation, and agroforestry, among others. These practices have however been applied in un-integrated manner, this has led to continuous loss of soil carbon; consequently, there has been a decline in crop yield especially cereals due to climate-change, soil degradation, pest, and disease burden, among other factors. Yet an increase in soil carbon by one in a degraded soil could increase cereal yield by up to 40 kg ha-1, for example, increase wheat yield by up to 20-40 kg ha-1 and Maize up to 10-20 kg ha-1 as well as reducing fossil fuel emission by 0.4-1.2 Giga tons of carbon per year. This review paper, therefore, looks at current ways of sequestering carbon and how these approaches can be improved and integrated to enhance soil carbon sequestration in cereal-legume cropping systems. There is a need to increase the production of cereals due to the increasing demand for cereals in sub-Saharan Africa and it is projected that, by 2050, the demand is expected to triple due to global population increase which is expected to outmatch production due to low soil carbon sequestration and soil fertility.
Abstract: Soil has the capacity to sequester about 50-66% of the 42-78 Giga tons of carbon lost per year. However, the capacity of the soil to sequester carbon is dependent on soil texture and structure, rainfall, temperature, farming systems, and soil management practices. Management practices to enhance soil carbon sequestration include; cover cropping, nu...
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