Separation into fractions

fractions of a chromatographic column separation

Bitumen can be separated into fractions with same physical and chemical behavior. The first separation is by distinguish soluble and insoluble parts. The solvent is often n-heptane but other solvents are also used, which lead to other results. The soluble part is called maltenes and the insoluble is called asphaltenes. Maltenes can be further separated into 3 fractions with a chromatographic column. The separation is based on adsorption to the stationary phase and redissolve potential of the mobile phase.
The cut points between the fractions is optical and done manually, even coupling with spectral devices is possible.

asphaltenes