?:definition
|
-
A unit of mass concentration defined as the concentration of one nanogram of a substance per one liter of the mixture, or one picogram of a substance per unit volume of the mixture equal to one milliliter, or one microgram of a substance per one cubic meter of the mixture. The concept also refers to the metric unit of mass density (volumic mass) defined as the density of a substance which mass equal to one nanogram occupies the volume of one liter.
|