I work on ZnS nanocomposite and study Mie theory about it. I want to calculate light transmission but I do not know how calculation of reflection coefficient in beer-Lambert formula?
I read a thesis where they calculated transmission through PE matrix with a low concentration of TiO2 spheres. I believe that your case might be similar. The permittivity can be for low concentration determined by dynamical Maxwell-Garnett where MIe theory is used.
Unfortunately, the thesis is in French, but it should not be problem if you follow the formula and look for details into the works cited in the thesis.