# Standard chemical potential and activity of asphaltene

Hi , this is my equation :
μA= μA0 + RTlnaA
A is the asphaltene in toluene solution . i want to calculate μA in different temperatures. where can i get μA0 and aA? tables? other equations?
μA0 is the standard chemical potential of asphaltene and aA is the asphaltene activity in solution.