Improvements in a fast potentiometric seawater alkalinity determination

In the present paper, we introduce some methodological improvements in a po tentiometric technique for determining seawater alkalinity. This fast metho d (about two minutes per sample) uses open Basks and an ordinary titration system without thermostatic bath. A new potassium hydrogen phthalate-borax 4.4 buffer is proposed to calibrate the electrode near the end point of the titration. The pH values of this new buffer at different pH-scales and tem peratures were determined using spectrophotometry. The combined use of this easy and improved two end-point method for alkalinity determination and ce rtified reference material enables the alkalinity to be determined with an accuracy lower than 1 mu mol kg(-1). (0.05%).