I am working with samples that are approximately 10-12.5 mL after preparation of vesicles ranging in size from 400 nm to 6 um. I believe I have different structures being formulated that is giving me such a broad size range. What chemical method could be done to determine what species are left as I filter the particle down (6 um filter to 1 um filter etc...) I need to really understand the particle and I feel a chemical test may be beneficial, but I do not know of any that can be done.