N O T E S F R O M T H E U. S. B U R E A U O F C H E M I S T R Y . *

HYDROGEN-ION CONCENTRATION IN BEET SUGAR FACTORY JUICES)

A REPORT OF A PRELIMINARY STUDY OF p]-I VALUES IN SUGAR

FACTORY LIQUORS, WITH SOME CONCLUSIONS.

By H. S. Paine, B. C. Sibley, and J. C. Keane.

[A~STRACT.]

SYSTEMATIC electrometric measurements of the pH of dif- fusion, first and second carbonation, and third saturation juices were made in two beet sugar factories during the I923 campaign and were compared with the titration values of the same samples. When the data are chronologically represented on co6rdinate paper, it is seen that, while the general contours of the correspond- ing pH and titration curves are somewhat similar, these two sets of values do not vary in a constantly silmlar manner. Determina- tion of pH reveals significant differences which are not apparent from titration data.

Determination of pH in beet sugar factories has the following possible advantages: ( I ) Closer control of carbonation and sul- phitation is possible. (2) Control by pH determination may be more rapid and less laborious than control by titration, provided that either a sufficiently simple colorimetric method or an automatic recording electrometric method is found to be satisfactory for the determination of pH. (3) It may be possible to apply pH control constructively so as to increase average non-sugar elimination. (4) pH measurements may be of value in connection with the analysis of ash for investigating certain factory problems involv- ing salts. It must be understood, however, that further investiga- tion is required in order to definitely determine whether or not these possible advantages can be realized.

Thymol blue and thymolphthalein test papers appear to be suit- able in some cases but not in others. The general applicability of these test papers remains to be determined upon the basis of more extensive trial.

* Communicated by the Chief of the Bureau. 1 Published in Facts about Sugar, 2o, No. 33 (Aug. I5, I925).

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