PG MG, or pg/mg, typically represents a ratio of picograms per milligram.
This unit is used to express a concentration, often in the context of analyzing trace amounts of substances within a sample. For example, in the context of hair analysis, it's used to quantify the amount of a substance present in hair.
According to the provided reference: Hair cutoff levels are expressed in picograms per milligram (pg/mg) of hair.
Here's a breakdown:
- pg: Stands for picogram, which is a unit of mass equal to one trillionth (10-12) of a gram.
- mg: Stands for milligram, which is a unit of mass equal to one thousandth (10-3) of a gram.
Therefore, pg/mg indicates how many picograms of a substance are present for every milligram of the sample being tested.
