In biochemistry, a trace element is a chemical element that is needed in minute quantities for the proper growth, development, and physiology of the organism.[1] In biochemistry, a trace element is also referred to as a micronutrient.
In geochemistry, a trace element is a chemical element whose concentration is less than 1000 ppm or 0.1% of a rock's composition. The term is used mainly in igneouspetrology.