Determination of zinc levels in commercially available vegetables in Kaduna, Nigeria and its environs

Abstract

Vegetables constitute an important ingredient of human diet that contain essential nutrients and trace elements. Environmental pollution has led to the contamination of some soils; just as waste water irrigation has resulted in the significant increase in heavy metal contents of agricultural land. Leafy vegetables accumulate higher metal contents than others. Zinc is an essential element known to be a micronutrient for mammals and plants for more than four decades. It functions as an integral part of numerous enzymes. Deficiency of zinc in the body has been associated with zinc carrier protein ZIP⁴ resulting in inadequate zinc absorption. It presents as growth retardation, severe diarrhea, hair loss, skin rash (most often around the genitalia and mouth), opportunistic candidiasis and bacterial infections. This study quantitatively determined the concentration of Zinc in Moringa oleifera, Vernonia amygdalina, , Adansonia digitata, Lactuca serriola, Amaranthus tricolor and Brassica olaracea purchased from Tudun Wada-Makera and environs . A 5.0 g quantity of each of the samples was treated to a wet digestion method. Concentration of zinc in the samples was determined using TAS 990 Intec Roma model of atomic absorption spectrophotometer (AAS). The results showed significant (p<0.05) concentrations of Zn²⁺ ranging from 0.012 ± 0.21 to 0.042 ± 0.01 mg/g (Mean ±S.E.M) with Amaranthus tricolor recording the highest concentration and Brassica olaracea recording the least .

Keywords: Atomic Absorption Spectrophotometer, Health, Tudun wada –Makaera, Vegetables, Zinc