Determinación de metales en cebolla de rama (Allium fistulosum L.), cultivada en suelos agrícolas cercanos al volcán Tungurahua

Abstract

Tungurahua, a volcano located in the eastern mountain range of Ecuador, since its reactivation in 1999 has alternated phases of high volcanic activity, with gas and ash emissions, explosions and lava episodes, as well as phases of low activity. Its last eruptive phase occurred between February and March 2016. In this study it was proposed to evaluate the bioavailability of metals in agricultural soils of the Quero canton through the correlation between total content, their soluble fractions and these in branch onion (Allium fistulosum L.). All metals were determined by spectrometry atomic absorption of flame or graphite furnace using certified reference monoelementals aqueous standards with which the calibration curve for each metal was prepared daily. Was analyzed the edible section of the branch onion and the data were expressed on fresh basis. The results showed that the metal intake by the branch onion was independent of the bioavailable fraction of the metal in the soil for all metals studied. The national and international standards were taken as reference values. In the legislations consulted, no specific data were reported for branch onion, however, reference values were taken for similar aliments. The soil was strongly acidic with negligible salinity and little organic matter. In summary, the content of potassium, manganese, strontium, copper, cobalt, magnesium, nickel, lead, iron and zinc in the samples of branch onion studied were below the maximum values allowed in the consulted norms.