**Abstract**

Minerals and elementary compounds of heavy metals are part of the ecosystem. Because of their high density and property to accumulate in stable forms, they are considered to be highly toxic to animals, plants and humans. Continuous mining activities and industrial effluents are the major sources which are adding toxic heavy metal ions into ecosystem and biota. Hence it is of utmost importance to quantify the levels of heavy metal ions in environmental and biological samples. On the other hand, it is equally important to remove the heavy metal ions and their compounds from the environmental and biological samples. That facilitates the environmental samples to be fit for using, consumption. In this regard, promising quantification methods such as electrochemical, spectrophotometric, naked eye sensing, test strips for spot analysis of heavy metal ions are considered for discussion. The main objective of this chapter is to give the overview of the most practiced quantification approaches available in the literature. Please note that reader cannot find the pin to pin publications regarding the same and that is not the aim of this book chapter.

**Keywords:** heavy metal ions, quantification, electrochemical and optical
