Water samples collected from a lake have been acidified with nitric acid and have turbidity less than 5NTU. Is it necessary to digest again for analysis in ICP-MS?
If this turbidity persists, i.e. no precipitate is formed, then the determined elements are evenly distributed in the water sample, even if they are part of the suspension particles, and probably they are not (e.g. in the case of Pb, Cd, Cu, ... ). That is, you can feed such samples into the spectrometer without any additional preparation, only after vigorous stirring, preferably with the help of ultrasound.