Characterization of element and mineral content in Artemisia annua and Camellia sinensis leaves by handheld X-ray fluorescence

Tea infusion is the most frequently worldwide consumed beverage next to water, with about 20 billion cups consumed daily. Artemisia annua leaves contain comparable levels of nutrients and mineral elements (dry matter basis) to many marketed tea (Camellia sinensis) leading us to suspect that this crop could also serve as an alternative source of nutrients for humans. Analyzer moveable X-ray fluorescence is used to evaluate the content of major, minor and toxic elements in A. annua from two different countries compared to six marketed tea in Senegal. To ensure qualified results, certified reference materials were used to perform the calibration. The very low and often negligible levels of inherent elements in the leaves, which are far below recommended toxic levels, establishes A. annua and selected marketed tea as a good reservoir of elements that might favour its use as a potential herbal tonic by humans. The mineral elements are present in different kinds of herbal leaves in various proportions depending on soil composition and the climate in which the plant grows.Keywords: X-ray fluorescence (XRF), Artemisia annua, Camellia sinensis, elements, leaves, medicinal plantAfrican Journal of Biotechnology Vol. 12(26), pp. 4179-418

Source Apportionment and Assessment of Air Quality Index of PM_2.5–10 and PM_2.5 in at Two Different Sites in Urban Background Area in Senegal

Identifying the particulate matter (PM) sources is an essential step to assess PM effects on human health and understand PM’s behavior in a specific environment. Information about the composition of the organic or/and inorganic fraction of PM is usually used for source apportionment studies. In this study that took place in Dakar, Senegal, the identification of the sources of two PM fractions was performed by utilizing data on the elemental composition and elemental carbon content. Four PM sources were identified using positive matrix factorization (PMF): Industrial emissions, mineral dust, traffic emissions, and sea salt/secondary sulfates. To assess the effect of PM on human health the air quality index (AQI) was estimated. The highest values of AQI are approximately 497 and 488, in Yoff and Hlm, respectively. The spatial location of the sources was investigated using potential source contribution function (PSCF). PSCF plots revealed the high effect of transported dust from the desert regions to PM concentration in the sampling site. To the best of our knowledge, this is the first source apportionment study on PM fractions published for Dakar, Senegal

Visualization 3: Super-flat coherent supercontinuum source in As_38.8Se_61.2 chalcogenide photonic crystal fiber with all-normal dispersion engineering at a very low input energy

Visualization 3 Originally published in Applied Optics on 10 January 2017 (ao-56-2-163