[Dwade]

I am currently running ortho-phosphate and nitrate/nitrite determination using an AAII continuous-flow autoanalyzer. I occasionally run a Total P or Total N determination as well using a potassium persulfate digestion in an acid pH using an autoclave as a heat bath. 

The problem I would like to ask about is Total P and Total N values that are often lower than my PO4 or NO3 values. Obviously TN and TP should be equal to or greater than NO3 or PO4 since the digestion converts organic forms to NO3 or PO4. Is this a problem that is encountered frequently and could anyone offer any insights or suggestions that might help me?

[el13]

 

I am currently running ortho-phosphate and nitrate/nitrite determination using an AAII continuous-flow autoanalyzer. I occasionally run a Total P or Total N determination as well using a potassium persulfate digestion in an acid pH using an autoclave as a heat bath. 

The problem I would like to ask about is Total P and Total N values that are often lower than my PO4 or NO3 values. Obviously TN and TP should be equal to or greater than NO3 or PO4 since the digestion converts organic forms to NO3 or PO4. Is this a problem that is encountered frequently and could anyone offer any insights or suggestions that might help me?

P is lower than PO4 and N is lower than NO3 or you are referring to P from PO4 and N from NO3?

Fixed your quoting for you --Macman104