18 Oct
1998
18 Oct
'98
4:06 p.m.
< I believe that "mmg" is still used as a
prefix in medical fields,
< but here it means (as far as I can figure out) "millimicrogram".
< Can someone correct me on this (I'm sure I'm wrong!)
A friend is a toxicologist and with it isn't PPM it's picograms/liter.
In the environmental testing field PPM, PPB and PPQ for part per quadrillion
are standard. Also nanogram, picogram and even femtogram are standard terms
for Mass spec. injection amounts.
Current Mass spec. detection limits are in the VERY low femtogram
quantities.
Dan Burrows
dburrows(a)netpath.net