The Nitrate/Nitrite and Lead Content of Some Leafy Vegetables Species Cultivated in the Lagos Metropolis, Nigeria

By Kudirat Margaret Ladipo, Oluseun Elizabeth Popoola, Funmilayo Doherty, Jocelyn Adelanke Odusanmi and Afusat Morenikeji Suenu.

Published by The International Journal of Science in Society

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The nitrate/nitrite and heavy metal (Pb) concentrations of four leafy vegetables species: Corchorus olitoriu (ewedu), Telfairia occidentalis (fluted pumkin), Amaranthus viridis (green), Vernonia amygdalina (bitter leaf) are the objectives of study. The vegetables, collected from five farms after harvesting were subjected to phenoldisulfonic acid method for nitrate and Nessler’s method for nitrite before analysis using a T80 UV/VIS Spectrophotometer. Atomic absorption spectrophotometer (Perkin Elmer Analyst 200) was used for Pb determination after acid digestion. The data were analyzed with ANOVA and Pearson Correlation analysis. The result shows that the average nitrate/nitrite contents of the vegetables were less than the ADI of European Commission. The highest and lowest average nitrate content (μg/g dry weight) was found for bitter leaf (101.63) and green (62.84) respectively while their nitrite values were given as 76.47 and 33.93μg/g dry weights. Green had the highest Pb content 4.36 while ewedu had the lowest 3.84 μg/g dry weight. The Pb levels which were not significantly affected by variations in locations (P>0.05), are above the FAO and WHO/EU joint limit, may predispose the consumers to low levels Pb poisoning. We conclude that the urban activities have significant effect on the vegetables and fertilizer application is acceptable.

Keywords: Nitrate, Nitrite, Lead, Vegetables, Lagos Metropolis

The International Journal of Science in Society, Volume 3, Issue 3, pp.61-70. Article: Print (Spiral Bound). Article: Electronic (PDF File; 871.986KB).

Dr. Kudirat Margaret Ladipo

Chief Lecturer, The Department of Polymer and Textiles Technology, Yaba College of Technology, Yaba, Lagos, Nigeria

Dr. Oluseun Elizabeth Popoola

Senior Lecturer, Department of Chemical Science, Yaba College of Technology, Yaba, Lagos, Nigeria

Dr. Popoola is a senior lecturer in the Department of Chemical Science, Yaba College of Technology, Yaba, Lagos, Nigeria and has been teaching inorganic chemistry and enviromental chemistry since Febuary, 2000. She received her B.Sc degree in chemistry from Ogun State University, Ago-Iwoye Ogun State in 1991, M.Sc in inorganic chemistry from the University of Ibadan in 1995, and Ph.D. in environmental toxicology from the University of Agriculture, Abeokuta, Ogun State in 2010. Her research interests involve environmental monitoring/assessment of pollutants and analysis of toxicants in foods. Her areas of emphasis include acid-clay reclaimation and physico-chemical assessment of spent lubricating oil; monitoring and evaluation of liquid effluent discharges of some manufacturing industries in the Ikeja industrial area of Lagos state; heavy metals in top soil and effluent from an electronic waste dumpsite; and bioremediation of soil contaminated with petroleum products using indigenous fungi. Her current research areas are: determination of oxalate content of some Nigerian tubers; the use of castor oil of in the production of biodegradable detergents and heavy metals in local facial cosmetics from South Eastern Nigeria. She is a member of the Chemical Society of Nigeria and the Institute of Public Analyst of Nigeria.

Funmilayo Doherty

Lecturer, The Department of Biological Science Technology, Yaba College of Technology, Yaba, Lagos, Nigeria

Jocelyn Adelanke Odusanmi

The Department of Chemical Science, Yaba College of Technology, Yaba, Lagos, Nigeria

Afusat Morenikeji Suenu

Student, Dept of chemical Science, Yaba College of Technology, Yaba, Yaba College of Technology, Yaba, Lagos, Nigeria