Assessment of essential and toxic elements in some kinds of vegetables.

Vegetables provide the human body with the essential bioavailable trace elements, and a constant supply of these various elements is necessary and highly recommended for daily life. Minor elements such as Ca, Fe, K, Mg, and Na as well as trace elements such as Cd, Co, Cu, Mn, Ni, Pb, and Zn were determined using an atomic absorption spectrophotometer in 12 different species of vegetables from Saudi Arabia (the Al-Taif district). These vegetables were cucumber, vegetable marrow, tomato, potato, green pepper, eggplant, carrots, parsley, lettuce, spinach, salq, onion, leek, watercress, and cabbage. The results reveal that the different element concentrations of each vegetable depend upon the selective uptake of the elements by the plant. Salq and watercress exhibited higher element concentrations than the other vegetables. Cluster analysis, principle component analysis, and transfer factor analysis of elements from soil to plant were applied to the elements database and produced good interpretations of the data. The element concentrations of these vegetables were within safety baseline levels for human consumption.