Fill the micro-cup with the powder (or the mixture of the powder and KBr).The diffuse reflectance accessory uses a focusing mirror to focus the beam on the sample surface and collect the IR energy. The micro-cup needs to be filled consistently in order to keep the focus.
Scratch the sample surface with a piece of abrasive (SiC) paper and then measuring the particles adhering to the paper.
Place drops of solution on a substrate. If colloids or powders are dissolved or suspended in a volatile solvent, you can place a few drops of the solution on a substrate, and then evaporate the solvent, subsequently analyze the remaining particles on the substrate.