Research Report RR:E15-1040
This study involves two methods for determination of chloride in 50% NaOH. The purpose of the study was to evaluate these two methods as more modern and objective approaches compared to the classical method existing in E-291 of Volume 15.05. These two electroanalytical procedures to be investigated involved potentiometric titration with silver nitrate and ion selective electrod potentiometry, respectively. It was anticipated that these procedures would allow determination of chloride in 50% NaOH (and KOH), at much lower levels of chloride as exist in Mercury Cell NaOH, for example. Another anticipated advantage was that the existing classical titration already on the books would be replaced with the new methods which involve no subjective judgement regarding a visual end point determination. Finally, it was hoped that cost of apparatus and instrumentation would not be prohibitive for implementing the two new procedures.
E291-18 Standard Test Methods for Chemical Analysis of Caustic Soda and Caustic Potash (Sodium Hydroxide and Potassium Hydroxide)
Committee D16 on Aromatic, Industrial, Specialty and Related Chemicals