Parts per billion (ppb)

Definition

Parts per billion (ppb) is a unit of measurement used to express the concentration of one substance in a solution. It denotes one part of solute per billion parts of the total solution.

5 Must Know Facts For Your Next Test

1. 1 ppb is equivalent to $1 \mu g/L$ when measuring concentrations in water.
2. PPB is often used for measuring extremely low concentrations of pollutants or contaminants.
3. In chemical solutions, ppb can be converted to other units like ppm (parts per million) by understanding the relationship: 1 ppm = 1000 ppb.
4. The sensitivity required for detecting substances at the ppb level typically necessitates sophisticated analytical techniques such as mass spectrometry or chromatography.
5. Regulatory agencies, such as the Environmental Protection Agency (EPA), set limits on pollutant levels in air and water using units like ppb.

Review Questions

Related terms

Parts Per Million (ppm): A unit of concentration denoting one part solute per million parts solution; equivalent to mg/L for aqueous solutions.

$\mu g/L$: Micrograms per liter, a unit often interchangeable with ppb when measuring concentrations in water.

$mg/m^3$: Milligrams per cubic meter, a unit used to express concentration in air quality measurements.