OXIDATION OF CARBOHYDRATES A S D FATS BY AIR I N PRESENCE O F YELLOW PHOSPHORCS BY S A C H I S D R A X A T H C H A K R A V A R T I A S D S . R . D H A R
I n previous communications’ from this laboratory, the phenomenon of induced oxidation has been extensively investigated. I t has been shown that solutions of carbohydrates, fats, etc., which cannot be oxidised under ordinary conditions can very easily be oxidised a t the laboratory temperature if a current of air is passed through the solution ih presence of substances like ferrous hydroxide, cerous hydroxide, manganous hydroxide, sodium sulphite, etc. I t has been shown that these easily oxidisable substances in course of their own oxidation by air induce or promote the oxidation of other substances (carbohydrates, fats, etc.) which have the potentiality of being oxidised under ordinary conditions. In a recent paper” Dhar has advanced an explanation of the induced reactions based on the generation of ions in chemical changes. It is well known that ions are generated in the oxidation with phosphorus. I t is very likely that these ions activate the molecules of oxygen which thus becomes reactive and induce chemical changes which are not possible with molecular oxygen. It is well known that the oxidation of phosphorus can be retarded by various substances. ThCnard was the first to observe that the oxidation of phosphorus is considerably decreased by the presence of some organic ~ a p o u r s . ~ Graham4 observed that alcohol vapour, ether, ethylene, naphtha, sulphuretted hydrogen, etc., protected phosphorus from being acted upon by oxygen. Thus these organic substances act as negative catalysts in the oxidation of phosphorus. Having investigated a large number of such reactions in which the oxidation of one substance is retarded by the presence of a negative catalyst, Dharj has put forward the view that the phenomenon of negative catalysts is possible when the catalyst itself is likely to be oxidised. Thus in every case of such negative catalysis, the catalyst simultaneously gets oxidised. Though sodium arsenite does not get oxidised under ordinary conditions by passing air through the solution, i t can be oxidised under the same conditions only if it is mixed with sodium sulphite or any other reducing agent. A t the same time, the oxidation of sodium sulphite is retarded. Hence it was expected that as the oxidation of phosphorus is retarded by the presence of some organic substances, it seems likely that these inhibitors also will get oxidised along u-ith the slow oxidation of phosphorus. The present investigation was undertaken J . Chern. Soc., 111, 690 (191;); Z. anorg. Chem., 122, 146 (1922); J. Phys. Chem., 29, 376, 799 (1925); 30, 939 (1926); 32, 1663 (1928). J. Phys. Chem., 28, 948 (1924). 3”Trait@de chimie,” 1, 236 (1816). Quarterly Journal of Science, 11, 63 (1629). Proc. K. Akad. Keten. .4msterdam, 29, 1923 (1921).
OXIDATION O F CARBOHYDRATES, FATS AND PHOSPHORUS
IIIj
with a view to observe whether phosphorus can be used as a suitable inductor like sodium sulphite, ferrous hydroxide, cerous hydroxide, etc. Also, as phosphorus gets oxidised with the generation of ions, it was expected that it would prove a very good inductor. The experimental results recorded in the following pages show that these expectations have been realised to a certain extent. Experimental Phosphorus was cut into small bits (each bit being approximately 0.00; gm.) and put in water. The solutions of carbohydrates or the potassium salts of fatty acids were added t o it and the volume made up to I O O cc. Dry air free from carbon dioxide was passed through the bottles, care being taken that the air came in contact with the phosphorus surface. d blank experiment was also conducted to see if diffused light of the laboratory had any effect on the oxidation. The fumes of the oxides of phosphorus which were generated from the bottle containing phosphorus, were passed through the same quantity of the solutions of carbohydrates or other substances. The residual carbohydrates were estimated by their reduction of Fehling’s solution, the precipitated oxide of copper being dried, ignited, and weighed. The oleate, stearate, and palmitate were estimated by their absorption of iodine monochloride, before and after the experiment. The oxalate and the oxalic acid were estimated by precipitation as calcium oxalate and subsequent titration with potassium permanganate in presence of acetic acid which dissolved the precipitate of calcium phosphite and phosphate. The results are given in Tables I-IV. TABLE
1
Carbohydrates and Bits of Phosphorus Amount of phosphorus 4.0 gm (Each bit = 0.005 gm) Amount of carbohydrates 0.1gm. Time hours Temperature 34O Carhohydrates
Starch Maltrosc Dextrose Glucogen Inulin Lactose Fructose Glucose Sucrose Galactose Arabinose
Percentage of oxidation in the diffused light of the laboratory
Percentage of oxidation in presence of Phosphorus
Percentage of oxidation in presence of Phosphorus only
Percentage of oxidation in presence of fumes of Phosphorus
Percentage of oxidation in presence of fumes only (5)
(1)
(2)
(3)
2.9%
3.2%
3.5%
0.6% 0.4% 0.6% 0.6%
1.8% 1.8% 1.7%
6.1% 4.4% 4.5% 4.9% 4.4% 3.9% 3.9%
1.7%
4.2%
1.6%
2
7%
1.9% 2.1%
(4)
1.7%
3.1%
2.6%
2.5%
2.8%
2.i%
2.6%
2.3%
2.1%
2.2%
0.5% 0.4%
2.2%
2.1%
0.4%
2.5%
2.2%
0.5%
4.i%
3.1%
2.2%
1.1%
3,i%
2.6%
1.6%
0.6% 0.6%
0.8%
3.2%
2
1,3%
0.5%
4%
1116
SACHINDRA NATH CHAKRAVhRTI AND N . R. DHAR
TABLE I1 Fatty Substances and Bits of Phosphorus Amount of phosphorus 4.0 gm (Each bit = Amount of fatty substance 0.1 gm Time j 3 hours Temperature 34' Fatty substances
Potassium oleate Potassium stearate Potassium palmitate Potassium oxalate Oxalic acid
0.005
gm)
(2)
(3)
(4)
(5)
4.1% 4.5%
3.9%
0.8% 0.9%
1.6%
6.7% 7.3% 6.1% 5.6%
1.4%
4.9%
(1)
2.6%
2.8% 2.1%
3.7%
4.0%
2.9%
4.0%
2.9%
3.5%
2'1%
111 Carbohydrates and Bits of Phosphorus Amount of phosphorus 4.0 gm (Each bit = Amount of carbohydrates 0.01gm Tune I I hours Temperature 36'
0.8% 0.8% 0.7%
TABLE
Carbohydrates
Starch Maltose Dextrin Glycogen Inulin Lactose Fructose Glucose Sucrose Galactose Arabinose
0.005 gm)
(5)
(3)
(4)
11
3%
5 9%
1%
8
1%
3
6 6% 5 7%
3 3 3 3 3
8% 8% 7% 47,
8 7%
4 9%
4
5 9% j 3% 407c
8% 8% 4 7%
10%
9 2% 9 0% i 4%
4
1 0 9 0
2%
40%
2
9% 9c.'c
7 2% 7 7% 8 8% 6 87c
4 2% 40% 3 8% 4 1%
(1)
j
4%
5
2
2 0%
I
4%
(2)
j
9%
0%
8% 5 9% 4 8% 4
4 5%
I
2%
0
47,
I 0%
8 7
0
8%
0
9 9
12%
3
0%
I 0%
2
3%
0
9C;.
TABLE IV Fatty Substances and Bits of Phosphorus 4.0 gm (Each bit = Amount of phosphorus Amount of fatty substances 0.1gm Time I I hours Temperature 34' Fatty Substances
Potassium oleate Potassium stearate Potassium palmitate Potassium oxalate Oxalic acid
(1)
(2)
(3)
4.4%
11.7%
7.3% 8.0% 6 .9yc
j.17~13.1% .97'
4.0'3~
IO
3.07'
10.0%
7.0%
2.3%
9.1%
6.8%
0.005 gm)
(4)
5'8% 6.7% j .4Yc 4.4% 3.6%
(5) 1.4%
1.67, I ,470 =.4%
1.3%
OXIDATION O F CARBOHYDRATES, FATS AND PHOSPHORUS
1117
h second set of experiments was started in exactly the same way, the only difference being that instead of small bits of phosphorus, colloidal phosphorus was prepared in the following way. About two grams of phosphorus were taken in 2 5 cc. of absolute alcohol in a small stoppered bottle and warmed in a water bath until the phosphorus melted. The bottle was vigorously shaken and in a short time the phosphorus was divided into very fine particles. The process was repeated several times so that a saturated solution of phosphorus was obtained. The solution was poured into water and a milky white emulsion was formed. In this way, a suspension of about 0.1 gm. of phosphorus was obtained. The next procedure was exactly similar to the previous ones. The oxidation of oleate, stearate, and palmitate could not be investigated in this particular case as the alcohol present interfered with the method of estimation followed in the case of these substances, by absorbing a large quantity of iodine. The oxalate was estimated by adding calcium chloride and dissolving the precipitated phosphates and phosphites by acetic acid and estimating the calcium oxalate with potassium permanganate. The other methods of estimation were similar to the previous ones. The results are tabulated in Tables V-VIII.
TABLE 5'
Carbohydrates
Carbohydrates and Colloidal Phosphorus Amount of phosphorus 0.1 gm Amount of carbohydrates 0.1gm Time hours Temperature 36' (1) (2) (3 1
Starch Maltose Dextrin Glucogen Inulin Lactose Fructose Glucose Sucrose Galactose Arabinose
Substances
Potassium oxalate Oxalic acid
3
2c;
8 8%
j Sc;
3
0°C
6 3% 6 9%
3 3cc
2
~"c
2
2°C
2
z
lffc
07 07
7 1% 6 970
I 97c 1 3 7
6 6 6 i 6
4% 0%
12$
5
570
2
2 0%
O ~ C
4mc
5%
4 4"c 4 9 5 4 8yc 4 05
4 4p' 4 5% j
5%
4 7%
4 3%
TABLE VI Oxalates and Colloidal Phosphorus Amount of phosphorus 0.1gm Amount of oxalates 0.1gm Time 53 hours Temperature 36' (1) (2 1 (3) I I
9% 6%
7
0%
6 4%
(4)
j.152
2
4 gpc
2
9% 5%
1118
S A C H I N D R A PI-ATH CHAKRAVARTI .AND S . R. D H h R
TABLE VI1 Carbohydrates and Colloidal Phosphorus Amount of phosphorus o I gm Amount of carbohydrates 0.1gm Time I I hours Temperature 36' Carbohydrates
Starch Maltose Dextrin Glycogen Inulin Lactose Fructose Glucose Sucrose Galactose Arabinose
j 4%
5
11
3 9% 3 9 7
9 oc;
3 9% 3 3% 3 1% 3 07 2
8 7
2
2rc
I
4c"c
05;
8 sc; 8 8 7
25
8 95 7 3 7 7 2 5 6 5 83 7 7 0 7 5 8 7
TABLE
(4 1
(3)
(2)
(1)
j
65
3 3 7
6 65 5 sc;
4
9 7
4
85
5 5
IC$
4
IS
0 7
4 9 7
4 0 7 4
1";
4 6%
407 3 sc; 4 o$
55
4
07
4 85
3
2 7
4 4;'
2
2
j
5
TI11
Oxalates and Colloidal Phosphorus Amount of phosphorus 0.1 gm 0.1 gm Amount of oxalate Time I I hours Temperature 36' Substances
Potassium oxalate Oxalic acid
(1)
3
2
2
6%
5
(2)
(3)
86 7 7 7 7
j zC;
4
5
3 6%
1 5
(4) 2
7
A third set of experiments was conducted under similar conditions but this time finely divided phosphorus (almost powdered) was taken as the inductor. Finely divided phosphorus was prepared in the following way. Two grams of phosphorus were taken in about j o cc. of water in a stoppered bottle and kept in a water bath until the phosphorus just melted. The bottle was shaken vigorously and in a short time, the phosphorus solidified but in very fine particles-almost to a powdery form. The advantage in working with this form of phosphorus was that on slightly agitating this phosphorus in water, a portion of it remained in a suspended condition temporarily, so when air was passed through such a mixture, a larger volume of air came in contact with the surface of the phosphorus than in the case of small bits of phosphorus. The next step and the methods of estimation were similar to the other ones. The results are tabulated in Tables IX-XII.
OXIDATIOS O F CARBOHYDRATES, FATS A S D PHOSPHORL'S
TABLE IS Carbohydrates and finely divided Phosphorus 2 . 0 gm Amount of phosphorus Amount of carbohydrates 0.1gm Time 5 4 hours Temperature 34' Carbohydrates
3
15
2
8%
14 i5 9 4 5
07
2 O$
II
2 2$
I2
2
11
0
I 9
(3) 6 7
( 2)
(1)
Starch Maltrose Dextrin Glycogen Inulin Lactose Fructose Glucose Sucrose Galactose Arabinose
oc; 4 7
9 9 5
11
6 6 5 9 oCc 9 8$ 9 4cc 80%
I
8 5
IO
07
8
I
85;
IO
8c;
9 orC
I
8 5
12
4 7
I
2 7
I O 2yc
9 orc
I
05
9 6 5
8 6 7
TABLE
IO
2 5
SC:
(4)
5 35c 4 15 3 8% 4 1c-c
3 9°C 3 5 3 1
3 SCC 4 orc 3 05 2 7 5
x
Fatty Substances and finely divided Phosphorus Amount of phosphorus 2 o gm Amount of fatty substances 0.1 gm Time 5$ hours Temperature 36' Fatty Substances
Potassium oleate Potassium stearate Potassium p.almitate Potassium oxalate Oxalic acid
(2)
117'; 13 9 5
2
8$
2
I
3 5 6%
I
3 5
11 2
9 8
'4)r
'3)c-
(1)
2 4 7
5
2C;
jS
9 3 c 11
1 ~ 2
4 2 6
5
0';
8 9 5 i 5';
3 lCc
i
2
2c;
4 I(
f ;
TABLE SI Carbohydrates and finely divided Phosphorus Amount of phosphorus 2 o gm Amount of carbohydrates o I gm Time 1 1 hours Temperature 34' Carbohydrates
Starch 1Ialtose Dextrin Glycogen Inulin Lactose Fructose Glucose Sucrose Galactose Arabinose
( 2)
(1)
5 4$ 5 2 7
3 3 3 3 3 3
8rc
zrC
I ; ;'1
3$
17 6'; 18 4 5 18 zrc lj 3$
2$
85 SCl,
0°C
2
9 5
2
icIc 4TC
I
22
(3) 16 gC; 9 9Cc 13 Sc; 14 6 5 14 4 5 I2
oc;
I j j$
I2
3$
16 5 5 19 4 7
13
55
15
sCC
16 j5 13 8$
14
3c;
I2
9 5
(4)
8 i 7 2 6 j
6 7 5 6
75
5 7'; j 7'; 5 7 6 2 4 8
4 orc
SACHINDRA NATH C H l K R A V A R T I .4SD N. R. DHAR
I120
TABLE XI1 Fatty Substances and finely divided Phosphorus lmount of phosphorus 2.0 gm Amount of fatty substances 0.1 gm Time I I hours Temperature 36' Fatty Substances
Potassium oleate Potassium stearate Potassium palmitate Potassium oxalate Oxalic acid
(1)
4
(4 )
(3)
(2)
f'c
1 7 4%
8
2 1 2c>
9
(5)
j 3Yc
26 5';
4
5
21
02
16
8 s
7
j%
3 ;'5 4 2c; 4 3 7
3 oc{
17
I(;
14
1%
j
8%
z
16
2
2
2
45
22
I?
7
13 8 7
2%
jco
j 1%
2
8$ 7 7
From the foregoing data it is quite clear that phosphorus can be used as an inductor in the oxidation of carbohydrates and fats. Another interesting fact is observed that even the fumes given off in the oxidation of phosphorus can induce the oxidation of those substances to a slight extent. This probably is caused by particles of phosphorus or phosphorus trioxide which are likely to be carried away by the air. As these experiments were conducted at a time when the intensity of sunlight was very strong, even the diffused light of the laboratory could oxidise a certain portion of the substances. Making allowance for the oxidation in the diffused light without any inductor, we find that phosphorus in the finely divided state induced the oxidation of carbohydrates and fatty substances to the greatest extent. Colloidal phosphorus comes next and then the bits of phosphorus. Of course colloidal phosphorus having the largest surface should have been the most reactive amongst the three varieties but as it was prepared from an alcohloic solution, the alcohol present retarded the oxidation very much. Moreover, as the amount of phosphorus available in the colloidal phosphorus was very small being only about 0.1gm. per experiment it was oxidised in a very short time. This is the reason why the oxidation of the carbohydrates and the fatty substances in presence of colloidal phosphorus as recorded in the present paper does not show change with time. Thus the amount of oxidation in I O hours is almost the same as the amount of oxidation in j hours. If however, phosphorus could be suspended in water in some other way without introducing any other foreign matter, other than the inductor and the acceptor, it is likely that the percentage of oxidation would be much higher. From the tables it would be apparent that in each case, starch is oxidised to the highest extent. Curiously enough, in all our previous communications on induced reactions with different carbohydrates we have found that starch can be very easily oxidised. We have shown in a recent communication that in these slow oxidations complete oxidation of carbohydrates, fats and nitrogenous substances to carbon dioxide takes place, without the formation of intermediate products. Hence, it is rather surprising how the complex mole-
O X I D A T I O N O F C A R B O H Y D R A T E S , FATS AND P H O S P H O R C S
I121
cule of starch is so easily susceptible to oxidation, whereas, glucose which is much simpler in structure, can not be so easily oxidised. This much is quite certain that in slow photochemical or induced oxidations, starch does not pass through the stage of glucose before its oxidation to carbon dioxide. In the oxidation of carbohydrates in presence of diffused light we find that the order in which they are oxidised are as follows:Starch > maltose > dextrin > glycogen > inulin > lactose > fructose > glucose > sucrose '> galactose > arabinose. The order is exactly the same as has been recorded in the case of the oxidation in presence of sunlight without any induct'or. However, the order is different in the case of the oxidation in presence of phosphorus. The order of the oxidation of carbohydrates in presence of each variety of phosphorus is the same and is as follows:7 Starch > sucrose > glycogen > inulin > dextrin > galactose > glucose > arabinose > fructose > lactose > maltose. Almost the same order follows in the oxidation in presence of the fumes of phosphorus and phosphorous trioxide. In the oxidation of the fatty substances, the oxidation follows the same order in all the three types that have been investigated and also the same order as in the diffused light. Stearate > oleate > palmitate > oxalate > oxalic acid. It appears also that finely divided phosphorus has the greatest power of inducing the oxidation. The next in order comes colloidal phosphorus in presence of alcohol and last the coarsely divided phosphorus. I n a foregoing paper we have shown that when a mixture of finely divided sulphur and phosphorus are kept under water a t the laboratory temperature and air is passed, along with the slow oxidation of phosphorus, sulphur is osidised to sulphurous and sulphuric acids. K e have repeated some of these experiments and we have observed that a mixture of finely divided sulphur mixed with small bits of yelloF phosphorus and kept under water a t z s 0 or 30' can be oxidised to sulphurous and sulphuric acids and these can be qualitatively estimated. Summary
A detailed experimental study has been made to ascertain whether phosphorus can be utilised as an inductor in the oxidation of carbonhydrate, fats and other substances and the following conclusions have been arrived at :Finely divided phosphorus in the course of its oxidation has the (I) greatest capacity of oxidising the carbohydrates and the fats, colloidal phosphorus comes second in order and small bits of phosphorus come last. I n all the cases, the oxidation increases with time except in the case (2) of colloidal phosphorus, where it does not vary much. This is due to the fact that the colloidal phosphorus prepared for this investigation is easily oxidised completely within six hours,
I122
SACHISDRA N A T H CHBKRAVARTI AND N . R. DHAR
(3) The fumes of phosphorus and phosphorus trioxide also induce oxidation of the carbohydrates, fats and other substances to a slight extent. (4) I n the diffused light of the laboratory, carbohydrates, fats etc. are appreciably oxidised by air a t the ordinary temperature. ( 5 ) Although colloidal phosphorus should have been the most effective inductor, its apparent ineffectiveness is due to the presence of alcohol which inhibits the reaction. (6) Under different conditions, amongst the carbohydrates, starch undergoes slow oxidation to the greatest extent. (7) Sulphur is oxidised to sulphurous and sulphuric acid by simply bubbling air through a mixture of finely divided sulphur and phosphorus kept under water a t the ordinary laboratory temperature. Chemical Laboralorzes, Gnzversity of Allahabad, A l l a h a b d , Iridza. M a y 19,1930.
