432
INDUSTRIAL AND ENGINEERING CHEMISTRY
VOL. 7, NO. 6
CONTENT OF SOILSAND SOILINCRUSTATIONS IN THE VICINITY TABLE 11. SELEKIUDI OF MONTROSE AND GRAND JUNCTION, COLO.
T h e s o i 1s o f t h e w h o 1e area concerned in this i n v e s t i g a t i o n are deLab. Field selenium rived from shales w h i c h c o n t a i n so. so. Location Material P. p . m. s e l e n i u m . The selenium content of B14412 18 S e a r main lateral 1 mile south of Chir e p r e s e n t a t i v e s h a l e s is shown in Salt crust loo.o peta (near B14424, Table I) T a b l e I1 by Nos. B12104, B12109, 14413 19 Near main lateral 1 mile south of Chipeta ( n e a B14424, Table I) Ooze in ditch 4.0 B15022, and B15065. The quantity 14414 20 Bar in Uncornpahgre River (near B14425 Table I) Sandy clay 9.0 found in the soils varies considerably 14415 21 Relief driinage ditch, 1 mile east of over the area. A few examples only Delta (near B14426, Table I) Ditch deposit 28.0 14416 22 Drainage ditch (near B14427, Table I ) Ditch deposit 1.5 are given in Table 11. 14442 28 Main drain 1.5 miles east of Loma (near B14419, Table I) Salt crust 16.0 Of special i n t e r e s t a r e s a m p l e s 260'o 14439 25 6.5 miles east of Fruita Salt crust Bl5075, B15078, B15079, B15082, and 15003 2 6 miles east of Montrose, Montrose County Clay soil 0-6 inch 3.5 B15085 of Table I1 b e c a u s e of t h e i r 15022 8 2.5 miles east of Montrose, Montrose County Gypsiferous shale 3.5 relation to samples B14418 and Bl5202 15054 4 Sec. 26 T.15 S, R.95 W., Delta of Table I. The new drainage ditch 4 Coundy Chipeta clay 0-12 inch 3.0 15060 5 See. 19, T.15 S.,R.95 W., Delta miles north of Mack was sampled by County Billings clay 0-12 inch 4,0 15075 1 Rec. 10, T.9 S., R.103 W., Mesa C. S. Howard only a few weeks after Billings clay loam 0-12 inch 2,0 County its c o m p l e t i o n and before any great 15078 1 See. 10, T.9 S., R.103 W., Mesa County Billings clay loam 36-48 inch 8.0 amountof drainage had taken place. 15079 2 See. 15, T.9 S., R.103 W., Mesa County Billings clay loam 0-12 inch 2.0 It was sampled again after i t had been 15082 2 Sec. 15 T.9 S., R.103 W., Mesa in operation for about 6 months, when Count'y Billings clay loam 36-48 inch 5.0 B15085 4 Sec. 15, T . 9 S., R.103 W . , Mesa it was delivering a small flow of water. 52, County Alkali crust 15102 13 1.25 miles east of White Water Billings clay loam 0-12 inch 3,O The water it c o n t a i n e d was seepage 2.0 12104 M27x 4.5 miles north of Loma, Mesa County Manoos shale through t h e s o i l , r e p r e s e n t e d b y 12109 M27x 5.5 miles north of Lpma, Mesa County Manoos shale 6.0 15022 8 2 . 5 miles east of Montrose, Montrose samples Bl5079 and B15082 (Table 11). 3,5 County Gypsiferous shale 15065 5 8 miles north of Delta, Delta County Mancos shale 2.0 The nonirrigated area adjacent to it is represented b y s a m p l e s B15075 and B15078 (Table 11). Sample B15085 is a seepage incrustation irrigated lands is made clearly evident by the data on the near the ditch. drainage waters examined. All the drainage waters examined from this section of Colorado contain selenium. The most These observations have a practical aspect aside from their scientific interest, in that they indicate clearly the possibility striking examples are furnished by Nos. B14421 and B14424, of improvement of seleniferous land by irrigation and drainboth in the Uncompahgre area, and by B14419 and B14418, both in the Grand Junction area. The source of the selenium age where such management is practicable. in the drainage water is clearly evident through consideration of the data of Table 11. On the banks of the drainage ditches Literature Cited occur salt incrustations and these are in effect seepage de(1) Byers, H. G., U.8. Dept. Agr. Tech. BUZZ.482 (1935). content from l6to 260 parts Posits. They range in (2) Robinson, w. O., Dudley, H. C., Williams, K. T., and Byers, per million. Even the ooze (B14413 and B14416, Table 11) H. G., IND.ENQ.CHEM.,Anal. Ed., 6, 274-6 (1934). in the ditches has a selenium content, and also a mud bar in the Uncompahgre river (B14414). RECEIVED September 2, 1935.
Semi-Micro-Kjeldahl Determination of Nitro and Azo Nitrogen ROBERT A. HARTE, 315 East 80th St., New York, N. Y.
S
EMI-MICRO adaptations of the classical Kjeldahl method, suitable for the estimation of nitrogen in combination as amine, amide, or imide, have been reported by Hitchcock and Belden (3) and Northrop (4). By modifying the method of Elek and Sobotka (9) for the determination of nitro nitrogen in micro- and macrosamples, a successful technic for the estimation of nitro and azo nitrogen on the semimicro scale has been devised.
Procedure An accurately weighed sample of the dried substance, to contain from 2 to 5 mg. of nitrogen, is introduced into a dry 100-ml. Kjeldahl flask having a constriction about halfway up the neck, avoiding, as far as possible, deposition on the neck of the flask. Three hundred milligrams of c. P. dextrose, 1 to 1.5 grams of potassium sulfate, about 20 mg. of small copper sulfate crystals, and a few bits of well washed alundum (grain size 14, boiled out 5 to 6 times with distilled mater until the washings showed no
change of pH), are added to the flask whose neck is then washed down with 4 ml. of concentrated sulfuric acid (sp. gr. 1.84), care being taken to leave the neck entirely free of adhering particles. The mixture is digested over a shielded microburner with the flask in a nearly horizontal position, the heat being applied through a 2.5-em. (1-inch) hole in an asbestos board. As soon as the digestion mixture has become homogeneous one drop of selenium oxychloride is added. Heating is continued until the solution is clear and for 15 to 20 minutes thereafter. The time of digestion varies from 35 t o 45 minutes, To the cooled solution 35 ml. of distilled water are added, and, just before distillation, the solution is made alkaline with 12 ml. of a clear 50 per cent sodium hydroxide solution, in the usual fashion. The distillation apparatus is the same as that described by Hitchcock and Belden ( 3 ) . The distillate is received in 25 ml. of 0.02 N hydrochloric acid, and the excess acid is titrated with 0.02 N barium hydroxide, using as indicator the mixture of methyl red and methylene blue described by Andersen and Jen-, sen (1). Blank values on the reagents vary from 0.10 to 0.20 ml. of 0.02 N solution. Typical analytical data are shown in Table I.
NOVEMBER 15, 1935
ANALYTICAL EDITION
TABLEI. SEMI-MICRO-KJELDAHL DETERMINATION OF NITRO A N D Azo NITROOEN Substance
Weight of Sample
Nitrogen Found
% 20.2
Theory
%
433
than the traces of moisture contained in the reagents causes excessive foaming which prevents satisfactory completion of the digestion. The method described permits of economy of time and substance with retention of a high degree of accuracy and precision. It has been used for more than a year for the routine analysis of new oreparations with continued satisfaction. KO special balance-% required, a fine analytical balance being completely adequate.
p-Nitroariiline, Kahlbaum
20.4
MQ. 4.13
p-Aminoaaobenaene, Kahlbaum
20.4 23.1
4.14 4.90
20.3 21.2
22.5
4 78
21 2
21.8
2.30
10.5
IO 63
23.6 19.9
3.11 2.72
13.2 13.7
13.33
Literature Cited
13.77
(1) Andersen, A. C., and Jensen, B.TN., 2. anal. Chem., 83, 114-20 (1931). (2) El!k, A,, and Sobotka, H., J. Am. Chem. floc., 48,501-3 (1926). (3) Hitchcock, D.I., and Belden, R. C., IND. ENG.CHEM.,Anal. Ed., 5, 402 (1933). (4) Northrop, J. H., J. Gen. Physiol., 13, 774 (1929-30); 16, 320 (1932-33).
MQ.
3-Nitro-5-carboxyphenylglycyl sulfanilic acid 3-Nitro-5-carboxyphenylglycyl aniline Helianthine
19.8 Benzenetlzoresorcinol 26.5 p-Nitromalanilic acid 30.8 p-Nitrobenzoyl tyrosine ethyl ester 24.3
2.72 3.44
13.7 I3.O
3,38
1.88
7.8
20.29 21 $2
l3.Os
I1.O2
7.83
It is extremely important that the flask be thoroughly dried before the sample is introduced, since the presence of more
R E C ~ I ~M E aDy 27, 1935.
Continuous Production of Distilled Water Free from Carbon Dioxide and Ammonia FREDERICK G. STRAUB, Chemical Engineering Division, University of Illinois, Urbana, 111.
T
HIS laboratory was recently faced with the necessity of continuously producing high-grade distilled water free from ammonia and carbon dioxide and having a specific conductance of 0.5 x 10-8 mho. or less. T a p water and steam were available (Tables I and 11). When tap water was used in a hardwater type of Barnstead gas-fired still the best distillate obtained had a specific conductance of 5.0 X l o e 8 mho. This was obtained with very little bleeding through a continuous overflow and with the condenser venting free steam. TABLE I. ANALYSISOF TAPWATERAVAILABLE SlOZ Ca Mg NHa Na So4
Cl
Alkalinity:
phenolphthalein, 0 ; methyl orange
TABLE11.
P. p 14 66 31 5 34 1 4 37
m. 1 9 4 3 8 2 0 6
ASALYSIS O F CONDENSED STEAM
Condensate Leaving Condenser A t 20' C.Q At 100' C.b Cot, p. p. m. 9 t o 16 0.7 to 1 0 "a, p. p. m. 10 to 12 PH 6 . 0 to 6.5 8.0 t o 9 . 0 a Specific conductance 16.6 X 10-6 t o 12.5 X lo-' mho. b Specific conductance 6.6 X l o w 6mho.
The conductance was determined by passing a small amount of the distilled water through a totally enclosed type of conductivity cell. The resistance was determined by means of a dial type of Wheatstone bridge and a pointer type of alternating current galvanometer using 60-cycle current. The cell constant was about 20. The water leaving the still passed through a tin pipe. The still was rearranged so that condensed steam from the steam heating system was used as make-up to the still, but again the best distillate produced had a specific conductance mho. The still was modified so that air, free of 5.0 X
from carbon dioxide and ammonia, could be added just below the water level and passed through the condenser with the condensing steam. The quality of the distillate remained the same and it was found to contain no carbon dioxide but appreciable amounts of ammonia. The condenser used to condense the steam from the steamheating system was then modified so that the condensate left the condenser a t 100" C. with appreciable amounts of uncondensed steam flashing to the atmosphere. Table I1 shows the composition of the condensate after being collected in this manner. The carbon dioxide was low, but the ammonia had n o t been materially reduced. With such w a t e r b e i n g f e d to the still, the ammonia would be c a r r i e d with the steam and ren!zin in the distillate. Tests were then run after continuously a d d i n g various amounts of FIGURE1. MODIFIED STILL sulfuric acid mixed w i t h s o d i u m dic h r o m a t e to the condensed s t e a m b e i n g f e d to the still and with the still a r r a n g e d so that a c o n s t a n t l e v e l w a s maintained by an overf l o w (Figure 1). When no air was b e i n g f e d to the still the distillate from the still had a conductance of 1.0 FIGURE2. OIL SEPARATOR X mho. and
u
