What is the difference between milligrams per liter (mg/L) and parts per million (ppm)?
The first, milligrams per liter, indicates the weight of a substance in a volume of solution (for example, 2 milligrams of iron in a liter of solution). Parts per million indicates the weight of a substance by weight of solution. For example, 2 parts per million could mean 2 pounds of iron in a million pounds of solution, or 2 milligrams of iron in a million milligrams (1 kilogram) of solution. For all practical purposes the terms can be interchangeable in seawater, because the difference is small. The two terms are identical only when the liter of solution weighs exactly one kilogram.
Related Questions
- I sent a solid sample to the laboratory for TCLP and they sent back results in units of milligrams per liter (mg/L). How can a solid sample have a concentration in terms of its volume in liters?
- What is the difference between milligrams per liter (mg/L) and parts per million (ppm)?
- How do I convert mg per liter (mg/L) to parts per million (ppm)?
