help converting metal ion counts

[Catalina]

Can anyone help me with how to convert parts per billion (ppb) to/from mcg/l or ng/ml?

[stevel]

A liter of water weighs 1 kilogram (kg) at 4 degrees Centigrade at a standard atmospheric pressure of 760 mm mercury.  A microgram (ug or mcg) is 1 millionth of a gram.  A kilogram (kg) is 1000 grams.  So 1 mcg/liter or 1 mcg/1kg or 1 mcg/1000g or 1/1,000,000 g/1000g = 1/1,000,000,000 or ppb or parts per billion.  So mcg/l = ppb = parts per billion.

A nanogram is 1 billionth of a gram.  A milliliter is 1 thousandth of a liter or 1/1000 kilogram of water or 1 gram.  So 1 ng/ml or 1 ng/g = ppb = parts per billion.

These samples must be reported as a solution of water (rather than a solution of alcohol or some other medium) for the conversion to be valid.

[Catalina]

So, what you are saying is that they are used interchangably?

[stevel]

Yes