Determination of trace metals in cottonseed oil and hydrogenated cottonseed oil

The main vegetable oils used in Egypt are cottonseed oil and hydrogenated cottonseed oil; these are used as salad oil and for cooking. Determination of trace heavy metals in the oils is important. This is because of the association of trace metals with the origin of the oils, metal processing equipment and catalysts used for hydrogenation, and toxicity of edible oils, and because of the effect of trace metals on the characteristics, such as colour and taste, of finished products.Iron, copper, aluminium and magnesium were found in the cottonseed oil. These metals were also found in the hydrogenated cottonseed oil, together with lead, silver and calcium. The amounts of metals were below the limits permitted by public health and safety regulations.