Parts per million
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Revision as of 15:20, 2 December 2005 by C M Edwards (talk)
Parts per million (abbreviated "ppm") is a measure of solution concentration. It is defined as the mass of the solute (solution component) of interest, divided by the mass of the entire solution, and multiplied by <math>10^6</math>.
Parts per million is a ratio of masses, not volumes, and is technically dimensionless. Approximate conversion from ppm to grams per liter is sometimes used for aqueous solutions, using the assumption 1 liter water masses 1000g under standard conditions.
1 ppm =
= 0.0001% by mass
= 0.001 g/L
