How incomplete digestion affects test results
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When testing for total phosphorus and total nitrogen in water quality, what impact will incomplete sample digestion have on the measurement results? Is it generally on the low side? Yesterday, I suddenly realized that the digestion instrument seemed to be unable to reach the required digestion temperature. I’m not sure whether the data collected yesterday are too high or too low; it’s impossible to compare them with the previous data. Also, if the heater used for dissolution doesn’t reach the required temperature, does it have to be replaced? Can it be repaired instead?
This post was last edited by Yang Qing on 2020-8-20 at 11:09. When an experiment requires digestion, it must be carried out under the conditions specified in the testing method (such as digestion temperature and time). Generally speaking, for samples that are required to be digested, incomplete digestion leads to lower results; it’s not clear if there are any exceptions. As for whether the heater can still be repaired, as you mentioned, you should consult the manufacturer or relevant repair technicians; they will assess the situation and get back to you.
Incomplete digestion will definitely result in lower, or even significantly lower, values for the determination of total phosphorus. There are also special cases: when determining the content of insoluble solids, anything that cannot be dissolved is considered an insoluble solid.