[RASMB] averages from SV

[Borries Demeler]

> 
> Hi everybody,
> 
> we're looking for the pertinent reference for calculating number- and 
> z-averages from dc/dt-distributions - any hints? Furthermore, are 
> there formula for getting these averages from c(S)- and vHW-distributions?
> 

Holger,

to get number averages, I presume you want number of molecules, right?
I guess in that case you need to make some assumptions about how the
measured s-value relates to mass so you can make the conversion to
numbers.  The exact conversion of course would then of course also depend
on the measurement mode (i.e, interference, or particular wavelength
and absorbance properties). All molecules in your mix better have the
same signal properties, for example, if you have a mixture of molecules
that have a different ratio of trp/MW, and you use absorbance at 280 nm
as mass measure, then your conversion is going to be wrong. Otherwise,
standard formulas for calc. Mw, Mn and Mz apply.

-Borries