https://doi.org/10.1351/goldbook.C01209
@C01281-1@ of a mixture the @A00297@ or @C01222@ of which can be varied independently. The number of components in a given system is the minimum number of independent species necessary to define the composition in all the phases of a system. It may vary with external conditions since additional chemical equilibria reduce the number of components. The term component is also often used in the more general sense as defined here under @C01281-2@.
Source:
[Terms]
See also:
PAC, 1996, 68, 957. (Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)) on page 966 [Terms] [Paper]