Convert from as, ass [Northern Europe] to nanogram

Unit Definition (as, ass [Northern Europe])
The as, ass [Northern Europe] is a traditional unit of mass for gold and silver, used in most of northern Europe but not in England. The unit varied in size from about 48 to 58 milligrams (0.75 to 0.90 English grain).

Unit Definition (nanogram)
The nanogram is a metric unit of mass equal to 10E-9 gram, or one millionth of a milligram.