I suggest microwave digestion is not required for water samples, it will require only filtration to remove any suspended matter. If you are taking about waste water containing some organic substances or having some color then (di-acid) digestion process is very much required before going for further analysis via ICP-MS or ICP-ES.

or you can follow APHA 2011 guidelines by clicking over link below:

https://www.standardmethods.org/

i agree for water samples, it will require only filtration to remove any suspended matter.

Hi there

I disagree with all the answers above.

it depends on the type of analysis you want to do

For "Total heavy metal analysis", you need to digest your water samples, without filtration and sampling is essential as you would need to get a representative sample containing all dissolved metals as well as suspended ones.

For total dissolved heavy metals, the common practice is to assume that a 0.2-0.45um filter would retain all suspended solids. This in theory is not true as many nanoparticles are suspended and not retain by those filters.

I hope this helps

I agree that for total dissolved heavy metals, the common practice is to filter by 0.45um filter paper which would retain all suspended solids. In practice suspended nanoparticles are not considered, which is considered as dissolved ones.