This depends entirely on the answer you want. If you are not interested in speciation, but only total concentration, the digestion may not be needed, unless the organic content of the sample interfere with the determination. If that is the case, digestion, or dilution may be needed.
This depends entirely on the answer you want. If you are not interested in speciation, but only total concentration, the digestion may not be needed, unless the organic content of the sample interfere with the determination. If that is the case, digestion, or dilution may be needed.