How is a Total Alkalinity endpoint chosen if the sample has never been analyzed before?

Document ID

Document ID TE106

Published Date

Published Date 27/05/2017
Question
How is a Total Alkalinity endpoint chosen if the sample has never been analyzed before?
Summary
Estimating total alkalinity endpoint on unknown sample
Answer
It can be difficult to know the correct total alkalinity endpoint is reached when testing an unknown sample. The steps below can provide an estimation of the correct endpoint using a pH meter.

1. Follow the steps of the alkalinity titration method, titrating to an endpoint of pH 4.5.
2. Use this result as an estimated measurement.
3. Repeat the test if the estimated measurement is significantly lower than 500 mg/L.

Next time this sample is tested, use the endpoint that most closely matches the estimated measurement.