extinction coefficient

[tuphysic]

Hi
Will somebody guide me how to calculate the extiction coefficient for a dye assembled onto Thin films (Langmuir-Blodgett films, thickness= one monolayer of dye on solid substrate)? Please reply

[pluto]

can you just scrape it off, weigh it, and then measure an absorbance specturm? extinction coefficient is based on the absorance of a 1% solution.