FIXED ENDPOINT TITRATION OF ALKALINITY IN ACID PRECIPITATION RESEARCH
Systematic recordings of alkalinity may give early warning of change in acidification status. Fixed endpoint titration is a method well suited for routine measurements. But, standardized procedures for alkalinity titration do not take into account errors in endpoint pH caused by stirring of the samples. The magnitude of this effect depends on individual and variable properties of each electrode. Exact recalculation of old results is therefore impossible. For one of our indicator electrodes the average undertitration was 25 ìeq/1. Such errors reduce the quality of alkalinity data and may obscure the often subtle changes in alkalinity caused by acidification.