A S D E SGIA\7E E RI N G C H E M I S T R ISINK^ 1s C A R B O N TsTRAClILoRIDE-Ground bone, nitrate of lime, cyanamid. grape pomace, aluminum nitride, nitrate of soda, sulfate of ammonia. acid phosphate,, rock phosphate, basic slag, dissolved bone black. a n i m a l charcoal, muriate and sulfate of potash. kainit.
Tabie I s h o w s t h e separation as regards t h e organic portions of 1 3 commercial fertilizers a n d z tankages. T h e y have been selected from some 3 j samples as being representative of t h e extremes a n d averages t h u s i:rr found. L -An inspection of t h e table shows large variations in the nitrogen content of t h e mixtures t h a t contribute to furnish t h e organic nitrogen found i n commercial fertilizers. I t varies from 2 . j 4 per cent in No. 1 2 t o 1 1 . 6 5 a n d 1 2 per cent in Nos. 9 a n d 13. The water - in sol u ble ni t r og e n indicates si mil a r ranges . The inorgctnic portions from t h e samples above enumerated h a w been tested as t o their insoluble nitrogen contcn: a n d its activity determined. The activity fount1 coinpares favorably with t h a t shown in Table I in n i l '>ut two cases. I n other words a high activity 'I.
;8
I
N o claim is made t h a t t h e separation is absolute. T h e scheme, however, serve8 t o separate readily t h e major portion of t h e organic nitrogen present, in a m o u n t s sufficiently large t o enable one t o conduct microscopical a n d chemical analyses a n d pot experiments. Numerous other applications suggest themselves, among t h e m being t h e separation of s a n d , dirt a n d mineral salts from organic drugs, feeding stuffs a n d condimental feeds. CLASSIFICATION FOR ORGANIC ~ - I T R O C . E V ACTIVITY AS DETERMINED BY ik,KALINE
PERMANCIVATE
THE
?vfE'CHOD
PORTIOS-FLOATS o s CARBONTETRACHLORIDE
i i i ~ i : I--ORGANXC
T h e aboi-e classification of materials used in t h e manufacture of commercial fertilizers may prove of interest in this connection.
Per cent nitrogen 7 -
EXPERIMENT STATION BURLINGTON, VERMONT
.&ORICULTURAL
-
REMARKS Indicated by visual inspection a n d analysis
,2
F
4.....
7.86 9.48 6.80 9.I 6
3
9 48
l... ?..... s.... .
.
b
Tankage 15. 16.
4.28
4.ii
2.Oi
3.03 1.40 3.02 2 18 0.84 I .4; I .9i 1.26 1.12
5.79 6.45 5.40
6.14 7.30 3.44 3.30
3.96 10.39
69 75 66 68 75 45 61 55
5.93 11.65 5.12 4.70 2.54 12.00 4 50
l.4i
3.23
2:
0.7Y 0.00 1.62
1.75 12.00 2.91
44
7.58 10.24
0.65 0 57
6.93 9.67
73 76
4.00
78 45
74
1('
THE AVAILABILITY OF N I T R O G E N I N K E L P By J O H S A . CPLLEK
Base mix, castor pomace and hoof meal
Tankage, castor pomace Garbage tankage present Dry mix, cinders, tankage Tankage, garbage tankage Dry mix. dried blood, tankage Garbage tankage present Garbage tankage Dry mix, kanona tankage Tobacco stems, castor pomace and tankage
in t!ie separated organic portion as determined by laboratory methods was nearly always accompanied by a similar activity for' t h e water-insoluble nitrogen carried down with t h e mineral portion of t h e sample. I t should be noted t h a t ground bone sinks in t h e reagent employed. The sunk portion, therefore, in the t w o tankages was largely bone. This was indicated not only b y visual inspection b u t by i t s nitrogen content oi 2.32 a n d 2 . 1 7 per cent, respectively, as well as by t h e PnOapresent. .I relatively high water-insoluble nitrogen percentage in t h e mineral portion of a fertilizer t h a t sinks b y this procedure is indicative of bone especially if t h e acti\.ity b y t h e alkaline permanganate method is over 60 per cent. Certain materials other t h a n those listed under t h e column headed "Remarks'! have been noted i n m a n y of t h e samples examined. Their n a t u r e will be further studied when time permits. One in particular is worthy of mention. I t occurs as small black pellets, which crumble easily between t h e fingers. Analysis shows these pellets to contain 3.12 per cent t o t a l nitrogen a n d ' 1.60 per cent water-insoluble nitrogen with a n activity measured b y t h e alkaline permang a n a l e method of 5 1 per cent.
Received April 14, 1914
I n view of t h e widespread interest in kelp as a possible source of American potash, some information as ' t o t h e value a n d nature of t h e nitrogen present becomes a factor of considerable importance. T h e average of a large number of analyses made b y Mr. T. C. Trescott,' of t h e Bureau of Chemistry, shows a n average of approximately 2 . per cent of nitrogen. If i t is proposed t o market dry kelp t h e value of this a m o u n t of nitrogen present is apparent. I n t h e experiments by t h e a u t h o r different methods were followed in order t o determine t h e availability of t h e nitrogen. Briefly t h e y consisted in following t h e official alkaline permanganate method,%a n d later with modifications of t h e same. ,4n a t t e m p t was also made t o secure availability percentages b y using t h e neutral permanganate method b u t this was found impractical because of a bulky residue a n d i t s resistance t o filtration. T a b l e I gives t h e results obtained in .the various experiments. I t will be noticed t h a t b y using t h e official method which provides for a n a m o u n t of t h e sample equivalent t o 5 0 mg. of total nitrogen, t h e availability percentages range from 13.44 per cent in sample number 40 t o 44.So per cent in sample number 19. By pursuing t h e column farther i t will be observed t h a t t h e per cent of availability generally increases with a decrease in t h e a m o u n t of sample used. I n other words i t appears t h a t t h e per cent of availability is inversely proportional t o t h e a m o u n t of sample. Kelp contains on t h e average about 60 per cent organic matter. Assuming t h e average nitrogen cont e n t t o be a b o u t 2 per cent, t h e a m o u n t of sample 1
TIIISJOURNAL, 4, 431; 6 , 28i and i ? 9 ; 6, 19.
2
Report on nitrogen Bull. 162, Bur. of Chem.
T H E J O P R N A L O F I N D I - S T R I A L A N D ENGI-VEERIlYG C H E M I S T R Y
Serial No.
TABLEI Per cent total nitrogen A
DescriDtion
~
Average,
1.87
Vol, 6 . S o 7
Per cent of total N available r-
B
C
D
E
__
__
__
__
29.81
47.41
81.25
95.84
A. Total nitrogen (N) analyses by T. C. Trescott, Bur. of Chem. B. By official alkaline permanganate method. C. By using one-half the amount of sample as prescribed by the official method. D. B y using 1 gram of sample and 3.25 grams of alkaline potassium permanganate. E. By using 1 gram of sample and 5 grams of alkaline potassium permanganate.
necessary t o supply j o mg. of nitrogen will be 2.5 grams. Of this a m o u n t I . j grams are organic matter. T h a t all this organic m a t t e r was not oxidized is evident from t h e fact t h a t in all t h e experiments conducted under this method t h e supernatant liquids after digestion were colorless. I n some unpublished results obtained b y Mr. A . R. Merz a n d Dr. W. H. Ross, both of t h e Bureau of Soils, i t was found t h a t a considerable amount of t h e nitrogen i n kelp was water-soluble. Mr. Merz in his experiments treated t h e leaves, stems a n d whole plant with t w o successive portions of water. These were allowed t o s t a n d for 48 hours. He t h e n filtered a n d analyzed t h e filtrates a n d residues. T h e results are given in Table 11: TABLE II-(PERCENTAGES) DeTotal WaterNo scriotion nitrogen soluble 1.10 2. I . . . . . . . . . . . . . . . . . . Leaves 0.40 2 . . . . . . . . . . . . . . . . . Stems 1.70 1.10 0 .20 3 . . . . . . . . . . . . . . . . . . Plant 2.04 0.55 4 . . , . , , , , , , . , , . , , , . Plant 0.35 5 . . . . . . . . . . . . . . . . . . Plant 1.58
io
Per cent of total 40.74 23.53 18.18 26.96 22.17
Dr. Ross in his experiment placed some leaves in a bomb a n d heated over night a t a temperature of 190' which gave a pressure of about 1 5 atmospheres. By this t r e a t m e n t t h e slimy organic m a t t e r was coagulated so t h a t i t could be readily filtered. After filtration t h e nitrogen was t h e n determined in t h e filtrate and residue. His results are given below: TABLEI11 Per cent of total material Soluble. . . . . . . . . . 0 . 7 8 Insoluble 0.57
........
Per cent of total nitrogen 57.77 42.33
I t is interesting t o note t h a t in Table I 1 t h e per cent of water-soluble nitrogen closely approximates t h e availability percentages given in Column B , Table I, while i n Dr. Ross' experiment t h e per cent of watersoluble nitrogen was considerably more. I n t h e next set of experiments one-half of t h e amount of sample as prescribed b y t h e official method was
used. I n other particulars t h e procedure was the same. Under those conditions t h e percentage oi availability was considerably increased. T h e averages reached 47.41per cent as against 29.81 per cent i n t h e official method. Likewise t h e supernatant liquids were colorless. Further experiments were made in order t o determine whether or not more nitrogen was made available b y using a larger a m o u n t of potassium peimanganate. The results in Column D, Table I. were obtained b y using I gram of sample with 3.2 j grams of alkaline potassium permanganate. T h e average percentage of availability under these conditions w a s 81.25 per cent. T h a t there was yet insufficient potassium permanganate present t o effect complete oxidation was evidenced by'the fact t h a t t h e supernatant liquids were colorless. I n t h e next set of experiments, I gram of t h e sample was treated with j grams of alkaline potassium permanganate. It will be observed t h a t t h e results here obtained approach 1 0 0 per cent a n d in a few cases are slightly over i t . Where t h e higher percentages prevail t h e supernatant liquid after digestion was colored while in t h e others there was just lacking a sufficient a m o u n t of potassium permanganate t o give t h e solution a permanent color. Judging from these results it appears t h a t with enough potassium permanganate present t o oxidize all t h e organic matter, all, or nearly all of t h e nitrogen in kelp is found t o be available. SUMMARY
I-The official alkaline permanganate method is not suited t o determining t h e available nitrogen in kelp. 11-By using increased amounts of potassium permanganate t h e percentage of availability is increased. 111-By using a sufficient amount of potassium permanganate t o oxidize all t h e organic m a t t e r present, all, or nearly all of t h e nitrogen is found t o be available. FERTILIZER IKVESTIGATIONS, BUREAU OF SOILS
U S. DEPARTMENT OF AGRICULTURE, w'ASHISGTON
