Analysis and Determination of Lead and Chromium in Commercially Purchased Vegetables (Carrots, Potatoes and Tomatoes)

Abstract

Excess trace metal contamination in vegetables is a growing concern globally. Plants can be contaminated by trace metals, and it is important to understand the degree of contamination and the inherent risk. Vegetables are a staple in human diets, thus knowing the level of concentration of these metals within the diet is increasingly important. This project is designed to assess levels of trace metals in vegetables using Atomic Absorption Spectroscopy. Atomic absorption spectroscopy (AAS) is an analytical technique that determines unknown concentrations of elements using absorption of light from the desired elements with the aid of the working calibration curve obtained from the series of standards. Tests were done on three different commonly vegetable available in the UK to identify whether levels of trace metals fall within safe levels for human consumption. The vegetables selected were carrots, potatoes, and tomatoes. The concentration within organic vegetables did not significantly differ from the non-organic ones, though the results show, in some cases higher concentration of chromium in the potato and carrot peel. This is worthy of note from a health and nutrition perspective especially for those people that have a deficiency of these trace metals in their body or conversely wanted to manage their intake. The mean concentrations of these metals are in decreasing order of >Pb>Cr in most vegetables but in some Cr>Pb. The good thing is that the concentrations of these metals in vegetables purchased in the UK all fall below the maximum limits set by WHO/FAO and are thus considered safe for human consumption.