1 microgram = 1 millionth of a gram or .000001 - so, just move the decimal point over to the appropriate position. As long as you don't change the value of the number, you can do what you want to it.
1 milligram = 1,000 micrograms
-- Take the number of micrograms per liter
-- Divide by 1,000
-- The answer is the number of milligrams per liter.
Example: 6 micrograms per liter = 0.006...
667,54 milligrams per liter = 667, 54 grams per 1000 liters (or 1 m3).
Liter or milliliter are units of volume, tonne is a unit of mass. We need the density of the solution to express the...