You fill the capillary cell with your sample, there is no extra ingredient. A typical sample would be a colloidal dispersion of nanoparticles in a dispersant, for example water, a buffer or ethanol. You can also purchase a transfer standard (ZTS1240) of polystyrene latex particles prepared to be used as supplied, directly from the syringe.
The actual measurement time is usually under a minute in automatic mode. However, you may want to allow the sample to temperature equilibrate for a couple of minutes before the measurement, and you may want to do a few repeats of the measurement. If you really need to do fast measurements then it could be setup in manual mode to do a measurement in ~15 seconds or faster (sample dependent).
