Indirect Method for Estimation of Sodium in Water Supplies J. R . ROSSUM, California Water Service Company, San Jose, Calif.
GUSTAFSON and Behrman ( I ) describe a simple method for calculating the noncarbonate solids in natural waters from
-
Sodium (P.P.m.) = 0.186 Kd -t 0.113 (alkalinity) 0.46 (hardness)
(1)
determinations of the alkalinity and conductance.
%sodium = 100 X hardness - 0.404 Kd 0.246 (alkalinity)
['
Table I. KO.
1
3
2
Sodium in Water 4
5
6
7
8
523 5,58
1345 1495
9
where Kd is the diluted conductance in micromhos and both alkalinity and hardness are in parts per million as CaC08. The method is of value in evaluating waters for agricultural use. Table I illustrates the results obtained from several waters differing greatly in composition. Nos. 1 and 5 are synthetic waters taken from the examples of Gustafson and Behrman ( I ) , 4 and 9 are taken from their table of natural waters: the others are natural waters tested in this laboratory. These waters represent extremes; the best results are obtained on moderately mineralized waters having no one constituent greatly in excess of others having the
10
P.P.M. as CaCOs Calcium Magnesium Sodium Bicarbonate Sulfate Chloride Nitrate Alkalinity Hardnesr Micromhos a t 2 5 O C. K Kd
119
Analysis Equation 2
0.0 -1.17
, , ,
452 471
1100 1228
127
2780
..,
72 ,,
53
..
1020 1087
Per Per Cent Cent Sodium Sodium 3 .1 4.6
8.0 7.4
9.7
8.1
23.5 24.9
33.3 33.3
44.9 44.9
Using the same method, it is possible to compute the sodium concentration with fair accuracy when the alkalinity, hardness, and diluted conductance are knoTvn. The alkalinity and hardness may be rapidly determined by titrimetry, and the diluted conductance is determined by diluting the water sample xith cool boiled distilled water so that the specific conductance is approximately 100 micromhos a t 25" C. This value, multiplied by the dilution factor, is the diluted conductance. Sodium is then found from the equation:
60.1 61.3
65.4 60.2
+
80.8 80.9
same valence sign. The method will fail in the presence of high potassium or ammonium concentrations. It is not applicable outside the pH range of 6 to 9. LITERATURE CITED
(1) Gustafson. H., and Behrman, A. S., IND.ENG.CHEM.,ANAL. ED. 11,355 (1939). RECEIVED February 9, 1948.
Determination of Wax Content of Raw Cotton Fiber Noncalidity of Preliminary Treatment with Hydrochloric Acid CLAIRE LESSLIE, LAMONT HAGANI, AND JOHN D. GUTHRIE Southern Regional Research Laboratory, New Orleans, La.
HE accuracy with which the known constituents of raw Tcotton fiber may be determined is of importance in work directed toward the detection and identification of unknown constituents. Knecht and Streat (9) and Fargher and Wigginbothani ( 2 ) have cast doubt upon the accuracy of wax values obtained by the usual methods. They showed that higher wax values could be obtained by disrupting the fiber structure with hydrochloric acid prior to extraction of the wax, but did not offer evidence that the additional extracted material was wax. With the advent of the Conrad alcohol extraction method ( I ) , which provides for a phasic separation of the wax from other substances, it seemed likely that an answer to this question could be found. However, even with this method, higher values were obtained with raw cotton folloxing treatment with hydrochloric acid. A sample of kier-boiled cotton fabric showed no increase in wax value following treatment with hydrochloric acid, indicat1
ing that the substance or substances responsible for the higher values were removed by kier boiling. When raw cotton fiber was given a preliminary exhaustive extraction with water it showed little or no increase in Tyax value due to treatment with hydrochloric acid. Data on six different samples of raw cotton fiber are given in Table I. Each value is the average of four determinations with a standard deviation of about 0.04%. The treatments prior to extraction with alcohol according to the Conrad method were: (1) extracted without preliminary treatment; (2) ground to pass B 60-mesh screen in a Wiley mill; (3) fumed with hydrochloric acid by being placed in a desiccator over concentrated hydrochloric acid for 24 hours; (4) wetted with hot water and extracted with water in a Soxhlet extractor for 48 hours, dried in vacuum oven a t 60" C., and air equilibrated; ( 5 ) water-extracted as described, dried, air equilibrated, and placed in a desiccator over hydrochloric acid for 24 hours. The data show that the sub-
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