doubly charged ion

A species that is formed when an ion is generated with a double positive charge as opposed to a normal single charge and produces an isotopic peak at half its mass. For example, the major isotope of barium at mass 138 amu also exhibits a doubly charged ion at mass 69 amu, which can potentially interfere with gallium at mass 69. Some elements such as the rare earths readily form doubly charged species, whereas others do not. Formation of doubly charged ions is also impacted by the ionization conditions (RF power, nebulizer gas flow, etc.) in the plasma discharge