I figured I'd go ahead and do the calculation so that everyone isnt just speculating. I havent seen anyone else attempt it, so I wrote it out in Mathcad, saved the pages as a JPG, and here it is. As usual, Photobucket ruins the images by funky compression, but I think you can make it out. Ill see if I can serve them from somewhere else so that they may load clearer. The basis for the calculation I have firsthand experience with in the lab, and is shown in greater detail in Grant Bunker's book on X-ray Absorption Spectroscopy. A simple version which I used can be reviewed in slide 46-48 of this: gbxafs.iit.edu/training/XAFS_sample_prep.pdf Now, keep in mind that if the particles are somehow surface stabilized or have some form of chemistry to keep them in solution and in small size (e.g. some kind of polymer, surfactant, etc.) then this may be less valid. More technical conversation would be necessary with LM, as well as to optimally run the experiment by vigorous mixing of LM doped appropriately into a virgin and used motor oil, then allow them to sit in a glass jar for timescales as shown below and observe. Enjoy and discuss!