Concentration correction problem

Hello everyone,  
I want to consult you all on a question. When I use the TMVOC module to simulate NAPL leakage, I want to know how to handle the calibration of contaminant concentration data afterward. That is, I can extract the oil phase saturation and the dissolved phase mass fraction of the contaminant from the program, but the data obtained from field monitoring are not these two values. How should this be dealt with?  
@Kenny, could you give some guidance or provide some reference documents?

Here, I express my sincere gratitude.