Separation of Methanol-water in a plate distillation column I conducted an experiment to separate methanol and water. I am trying to determine the mole fraction of the distillate collected but having a little trouble with the calculation.

So i had a flow rate of 55ml/min. When i collected my sample i got a specific density of 0.815 and  a volume of 334ml. I tried to work out the mass but i cant seem to use specific density as its a ratio so has no units. 

Would i just assume the specific density is the density and set units to g/cm3 so i can get the mass of the distillate , the concentration and then determine the mole fraction from there or does that not make sense
?
Yes, you can do that.

Specific gravity is considered as unitless ratio of density related to water density.

Density as a specific mass is mass per volume, in $\pu{ g/cm^3}$ or $\pu{ kg/m^3}$

Regardless of country specific quantity naming convention:

Numerically, for 3 valid decimal digits,considering value uncertainty, the unitless quantity and quantity in $\pu{g/cm^3}$ are about interchangeable at $\pu{20 ^{°}C}$, as water density is near $\pu{0.9982 g/cm^3}$