Ah-.ilLYTICdL E D I T I O S
32
r u n varying amounts of the solution, for example, 5.5, 5.6, 5.7, 5.8, 5.9, and 6 cc.. into these test tubes from a buret. Effect a good mixture in the tubes and place the rack in a boiling water bath for 20 minutes. Then cool and inspect for the tube showing complete reduction of the copper, using ferrous ammonium sulfate as an indicator or the color change method. Calculate the diastatic value from Ling's formula based on the Lintner scale. However, a few changes in the constants are necessary to accommodate the formula to the concentrations used. According to Ling's ( 1 ) formula,
where A = diastatic power x = cubic centimeters extract in fully diluted starch solution, on the 1-hour reaction y = cubic centimeters needed to reduce 5 cc. Fehling's solution In this case x = 0.5, as a 30-minute reaction was used
5
y = - y', as 2 cc. Fehling's solution was used 2 -
Then A =
800
'Oo0 or A , Y 0.5 X 65 y" ~
.L
If y'
= 53,
A = 151
The foregoing test is carried out under the conditions laid down by Kjeldahl's law of proportionality; also the Lintner scale is preserved. Walpole's acetate buffer consists of 12 cc. sodium acetate (normal), 8 cc. acetic acid (normal), and 80 cc. distilled water. The results in Table I were obtained in this laboratory,
Vol. 2 , s o . 1
using llerck's soluble starch and two different makes of potato starch. All the tests were under p H control. Table I DATE
K I X DO F 1 I A L T
SAMPLE
July 29 July 20 Aug. 5 Aug. 6 hug. 6 .Lug. 8 Aug. 8 Aug. 9 Aug. 11 Aug. 12 .4ug. 1 2 .Lug. 12
Distillers Distillers Distillers Brewers Distillers Distillers Brewers Brewers Distillers Distillers Distillers Brewers
1 2 3 4
3 6 4
7 8 9 4
---DIAZTATIC POWER--Soluble Potato Potato starch 1 2 'Lintner Lintner Lintner 151 140 ... 151 140 .. . I57 145 ... 119 116 , . . 136 138 .. . 148 138 ... 120 121 ... 121 118 ... 150 140 ... iik 138 ... 138 136 ... 116 118
All the samples in Table I check fairly well, except sample 3 analyzed on August 6. The soluble starch result is very low, but the potato starch results did not fall accordingly. Whether or not this method is universally accepted, it contains two principles that must be accepted to give a semblance of order in the present chaos. The combination of these two principles appears in no other method. One is p H control. The other is a standard niedium upon which the diastase is to react. Refined potato starch is a far more standard reagent than the soluble starch made from it. Literature Cited (1) Baker, "Allen's
Commercial Organic Analysis," Vol. I, p. 137, Blakis-
ton's, 1909. (2) Brown and Morris, J . Chem. SOL.,450 (1889). ( 3 ) Lintner, Z . p r a k f . Chem., 386 (1886). (4) Lintner, Z. ges. Brnuw., 329 (1903).
Ash and Electrical Conductivity of Sirups and Molasses Derived from Sugar Cane' F. W. Zerban a n d Louis Sattler SEW Y O R KS C G A R T R A D ELABORATORY, 80 SOUTH S T R E E TNEW , Y O R K N. , Y.
RAPID and accurate conductometric method for the concentration of total solids, namely, around 5" Brix (that determination of ash in raw cane sugars was described is, a t a n ash concentration of about 0.05 gram or less in 100 in a previous paper (7'). The percentage of ash (sul- ml. of solution), the effect of the nature of the non-electrofated ash less 10 per cent) is 0.0001757 (9.13 K 1935 - K 1 ) lytes becomes small. Such a low concentration is therefore where K is the specific conductance x 106 of the sugar so- better adapted for devising a conductoinetric method for lution itself and K1 is that of the solution acidified with determining the ash in sugar products. Honig ( I ) , as well hydrochloric acid, under specified conditions of concentra- as Spengler and Toedt ($), have called attention to this fact, tion. This mathematical expression mill be referred to as and the present writers (8) have confirmed it by experiment. the "conductometric formula." Experimental Procedure The investigation previously reported was extended to I n the conductometric method for detexmining ash in cover various types of sirups and molasses in order to ascertain whether the method would give correct results under raw cane sugars, the writers, following the example of Lange comparable conditions for these products also, or whether and of Toedt, use 5 grams of sugar in 100 ml. Under these conditions, an addition of 5 i d . of 0.25 A- hydrochloric acid it would require some modification. Lunden ( g ) , Sandera (S),and Honig (1) have pointed out t o 200 nil. of the sugar solution more than displaces all the that the depressing effect, on the conductance of the elec- neak acids of the salts contained in the sugar, and the controlytes, of non-sugar non-electrolytes contained in low- ductance measured a t that point lies JT-ell within the straight purity products is greater than that of the same concen- part of the displacement curve. The range of the ash pertration of sucrose in high-purity products. L u n d h and centage in cane sirups and molasses is roughly about 10 times Honig have made use of this fact to judge the quality of sugar as high as in raw cane sugars. While the raw cane sugars products by calculating the ratio between the chemically contain from 0.2 to 1 per cent of ash, cane sirups have about determined ash and the specific conductance, measured a t 1 to 4 per cent, and molasses and barrel sirups about 5 t o high total solid concentration, above 50" Brix. On the other 10 per cent, or a little more. I n order to be able to use again hand, if the conductance determinations are made at a low 5 ml. of 0.25 S hydrochloric acid to 200 ml. of solution, and still have enough acid to more than displace the weak acids, 1 Received M a y 4, 1929 Presented before t h e Division of Sugar it 1%-asnecessary to use only one-tenth of the quantity of Chemistry a t t h e 77th Meeting of t h e American Chemical Society, Columbus material employed in the case of raw sugars. For this reason Ohio, April 29 t o M a y 3, 1929
A
+
INDUSTRI.4L A N D E,VGINEERIXG CHEATfISTRY
January 15, 1930
0.5 gram of sirup or molasses was dissolved t o 100 ml., and thus the actual salt concentration in the solution was of the same order as that for the raw sugars previously analyzed. The non-electrolyte concentration in these solutions was naturally very much lower than that in the raw sugar solutions, but this difference could be corrected by adding to the solutions, before making u p to volume, 4.5 grams of sucroSe to the 0.5 gram of sirup or molasses, thus imitating the composition of a raw sugar. Conductance determinations, with and without the addition of hydrochloric acid, were made both on the solutions containing no extra sucrose and on those to which sucrose had been added. A slight correction had to be applied for the conductance caused by the small quantity of salts in the Domino tablet sugar. The exact experimental procedure was as follows: Twentyfive grams of the sirup or molasses were weighed out on a sugar balance and dissolved in 100 ml. of hot conductivity water. The solution was filtered by suction into a 200-ml. volumetric flask through a mat of filter paper pulp covered with asbestos (6). The filter mat was washed repeatedly with hot water, and, after thoroughly mixing the solution, the volume was made u p to mark a t 20" C. Two 20-ml. portions of the solution were pipetted into weighed silica dishes and evaporated to a thick sirup on the water bath. Sulfated ash determinations were made on these two subsamples. For the conductivity determinations, 20 ml. of solution were diluted to 500 ml., and another 20-ml. portion was added to 22.5 grams of Domino tablet sugar in a 500-ml. flask. The final volumes were made up to mark a t 20" C. Conductances were measured in the usual manner ( y ) , without and with the addition of 5 ml. of 0.26 N hydrochloric acid to 200 ml. of the solution. The detailed results of the investigation have been assembled in a series of tables arranged in the same manner as those in the articles already printed. Mimeographed copies of these complete tables may be obtained from the writers upon request. C Ratios
I n the previous work on raw sugars the C-ratio method gave an average deviation, plus or minus, from the result of the chemical ash determination of 0.0158 per cent and a maximum deviation of 0.07 per cent. The application of the conductometric formula reduced the average error to 0.0085 per cent and the maximum error to 0.03 per cent, which maximum was found only in 3 cases out of a total of 277. As the sirups and molasses were analyzed a t a 10 times greater dilution, i t would be expected that the average and maximum errors should be about 10 times as great as with the raw sugars. This would be proportionately of the same magnitude on account of the difference in the ash percentage. The tables show that the errors actually obtained with sirups and molasses are approximately of the expected order, although the average, as well as the maximum, errors are slightly larger. For the C-ratio method, with addition of sucrose, the average error is 0.184 per cent and the maximum is 0.84 per cent. For the conductometric formula the average error is 0.121 per cent and the maximum is 0.47 per cent. I n the tests without added sucrose the same figures are, respectively, 0.177, 0.81 and 0.121, 0.41. But with this improved method only 3 samples out of a total of 205 showed an error greater than 0.35 per cent in the tests with sucrose and 5 samples in the tests without sucrose. I n judging the differences between the chemical and the electrical methods, it must be kept in mind that the chemical ash method itself is not very accurate. I n a cooperative investigation carried out some years ago by the Association of Official Agricultural Chemists (6) i t was found that the average of duplicate determinations of sulfated ash on
33
final molasses made by one operator may differ as much as 0.85 per cent from the result of another operator using the same method. The C ratios found for the different classes of products are presented in Table I. Table I-C PRODUCTS
Ratios (A) (N) WITH WITHOUT SUCROSESUCROSE B/A P e r cent
Raw sugar factory: Cuban blackstraps Porto Rican blackstraps First and second molasses Cane sirups Refinery: Filtered sirups Unfiltered sirups Final sirups (refinery X) Final sirups (refinery Y ) Final sirups (miscellaneous)
17770 17160 16660 15460
16040 15540 14920 13760
90.26 90.56 89.56 89.00
16150 16260 17350 17340 17260
14710 14820 15700
91.08 01.14 '30.49 91.00 90.50
15700
15630
The C ratios themselves are of no great significance, because, as has been shomn previously, they are largely influenced by the relative proportions of the various ions present, especially the anions. However, the relations between the C ratios without and with added sucrose are of interest, because they give an approximate idea of the depressing effect of the non-electrolytes on the conductance of' the electrolytes in the solution. The value of the coefficient a: in the Arrhenius formula cannot be calculated directly from these average ratios, but actual determinations of this coefficient have been made on some individual products of various classes. These gave the results shown in Table 11. Table 11-Value of Coefficient a PRODUCTS COEFFICIENT a Raw sugar factory: 0,0334 Porto Rican blackstraps 0.0334 First and second molasses 0,0321 Cane sirups 0.0330 Average Refinery: 0,0300 Filtered sirups 0,0265 Unfiltered sirup 0.0273 Final sirup (refinery X) 0 0289 Final sirups (miscellaneous) Average 0 0282
The general average for all sirups and molasses is 0.03026, compared to 0.03078 found by Lange for beet sugar products. Conductometric Formula
WITH ADDEDSucnosE-In these tests the composition of the solution approached that of a solution containing 5 grams of raw sugar in 100 ml. It would therefore be expected that the correction formula, taking into consideration the conductance after addition of acid, should hold for these solutions, the only difference being that the results would have to be multiplied by 10. This conclusion has been confirmed experimentally for the sirups and molasses produced in raw sugar factories. The formula per cent ash = 0.001757 (9.13 K 1935 - K,)gives closely agreeing results for intermediate and final molasses, more accurate than the results based on average C ratios for each class of product. The agreement is not so good for the cane sirups. With this class of products the errors by the conductometric formula are mostly on the negative side, although they are all within the limit of 0.24 per cent. It will be remembered that the curve on which the conductometric formula is based mas obtained with raw sugars, the ash of which was in practically all cases above 0.3 per cent. The portion of the curve below this figure had t o be obtained by extrapolation, and its exact trend is therefore uncertain. hIost cane sirups contain less than 3 per cent of ash, corresponding, for the experimental procedure used, to 0.3 per cent in raw sugars. For this reason the conductometric formula need not give very accurate results. A slightly modified formula, 0.001757 1976 - K1), greatly reduces the errors obtained (9.13 K
+
+
ANALYTICAL EDITION
84
with the original formula. The original formula, however, should give correct results if, instead of 0.5 gram, 2 grams were used in 100 ml. and the result divided by 4. It was impossible to study this question further, because cane sirups spoil quickly, and the samples originally received have long since been discarded. An investigation of this nature can be carried out better in the immediate vicinity of the factories. Although it might be supposed that the conductometric formula applied t o solutions containing the proper quantity of added sucrose should give accurate figures for refinery products also, this was found not to be the case. The treatment with boneblack evidently causes a profound change in the character of the products, and this effect increases with the relative quantities of boneblack used. For filtered sirups the factor in the formula is much smaller than for the sirups and molasses produced in the raw sugar plant, and for unfiltered sirups it is slightly higher than for filtered. Final sirups undergo less boneblack treatment than either filtered or unfiltered sirups. For this reason the factor lies somewhere between that for unfiltered sirups and that for the products of the raw sugar factory. As would be expected, it varies somewhat for different refineries. The factors actualIy found for each of the refinery products are shown in Table 111. WITHOUT ADDED SUCROSE-The corrective expression 1935 - K J was established in the presence of (9.13 K about 4.8 grams of total sucrose in a 100-ml. solution, and there is no a priori reason why it should also apply to solutions containing only a total of 0.5 gram of sirup or molasses in 100 nil. However, experiments have proved that even in the absence of added sucrose the conductometric formula generally gives better results than the C-ratio method for products of the raw sugar factory as well as of the refinery provided only that the factor 0.001757 is changed t o take care of the smaller non-electrolyte concentration and of the boneblack effect. For sirups and molasses from raw sugar plants the appropriate factor is 0.001640. This holds well for all the molasses, intermediate as well as final, but again not so well for the cane sirups, for reasons already explained.
+
PRODUCT
METHOD C ratio Formula C ratio
Cuban blackstraps Porto Rican blackstraps First and second molasses Cane sirups Filtered sirups Unfiltered sirups Final sirups (X) Final sirups (Y) Final sirups (miscellaneous) All products
Formula C ratio Formula C ratio Formula C ratio Formula C ratio
ii
Formula C ratio Formula
VOl. 2, No. 1
+
For the cane sirups a modified formula, 0.001640 (9.13 K 2047 - K1), is better. If, however, a larger quantity of sirup, say 2 grams, were dissolved to 100 ml. and the results divided by 4, the original formula with the factor 0.001640 should give correct results. As in the tests with added sucrose, the factors for the boneblack-treated products, without sucrose, are again lower than those for the products of the raw sugar factory. Filtered sirups give the lowest factor, as before, unfiltered sirups a slightly higher one, and final sirups a factor lying between that for unfiltered sirups and that for raw sugar products. The factors by which the expression (9.13 K 1935 - K1) must be multiplied are summarized in Table 111.
+
T a b l e 111-Factors
for Determining Conductometric Formula
FACTOR
With sucrose
PRODUCTS Raw sugar factory: Cuban blackstraps Porto Rican blackstraps Intermediate molasses Cane siruDs Refinery: Filtered sirups Unfiltered sirups Final sirups (refinery X) Final sirups (refinery Y ) Final sirups (miscellaneous) 0 See text for modified formula.
Without sucrose
0.001757 0.001757 0.001757 0.001757a
0.001640 0.001640 0.001640 0.0016400
0 001647 0 001662 0.001731 0 001700 0.001710
0 001551 0 001566 0 001622 0.001590 0.001596
Comparison of Results Obtained by Two Methods
The deviations from the chemical ash figure for all the products investigated and for both the C-ratio method and the conductometric formula method, with and without added sucrose, are summarized in Tables IV and V. I n Table IV the deviations are arranged in steps of 0.1 per cent, beginning with 0.05 per cent, through t o 0.85 per cent. These gradations were adopted because the corresponding table in the previous article on raw sugars gave the deviations in steps of 0.01 per cent, beginning with 0.00 per cent, up to 0.07 per cent. I n calculating the errors for the raw sugars, figures up to 0.005 per cept were reported as 0.00 per cent, up to 0.015 per cent as 0.01 per cent, and so
T a b l e IV-Deviations f r o m C h e m i c a l Ash F i g u r e NUMBBR OF SAMPLES I N WHICH THE CALCULATED ASH CHECKS WITH THE CHEMICAL ASH WITHIN: 0 38% 0.457, 0.587, 0 66% 0.75% 0.85% 0 . 2 5 %> 0.15% 0.05% WITH SUCROSE
8 6 3 4 3 1 7 4 6 12 3 4 11 16 4 6 2 3 47 56
21 23 9 8 5 5 15 16 14
19
8
33 40 13 21 8 3 120 140
25 32 9 9 7 10 16 18 19 22 6 7 41 48 21 32 7 7 151 185
28 39 10 10 9
29 41
32
.. ..
3.5
40
..
..
.. ..
..
'9
'9
.. io
18
..
io
22
.. .. ..
.. .. ..
.. ..
'7
.. .. .. .. ..
..
..
..
..
.. .. ..
..
..
..
.. ..
..
.. ..
47 51 30 38
51 34 38
38 35
39
li6 202
187 204
194 205
199
..
204
.. ..
36
40
'9
io .. .. .. .. ..
..
..
..
..
..
.. ..
41
.. .. .. .. 20;
..
WITHOUT S U C R O S B
Cuban blackstraps Porto Rican blackstraps First and second molasses
C ratio Formula C ratio Formula
i
Cane sirups Filtered sirups Unfiltered sirups Fiual sirups (X) Final sirups (Y) Final sirups (miscellaneous) All products
C ratio
9 12 5 3 4 2 4 2 3 S 2 4 15 2; 15 2 2 49 72
19 24 5 8 5 7 16 S
11
'3
5 34 43 15 24 4 4 118
140
25 35 9 0 S 10 17 13
1s
20 6 6 42 50
22 33 6 5 151 181
29 41 9 9 9
..
17 18 21 21 7 7 49 51 29 36 7 7 177 200
30
io
10 9
ia 22 22
..
..
51
..
35 35
..
189 205
34
.. ..
.. ..
.. .. .. .. .. 37 .. .. 19;
..
..
41
.. .. ..
..
.. .. .. ..
.. .. .. .. ..
..
.. .. .. ..
38
39
.. .. .. .. .. .. .. ..
199
2ai
266
.. ..
.. ..
..
.. ..
.. .
I
INDUSTRIAL AND ENGINEERING CHEMISTRY
January 15, 1930
on. Thus the gradations in Table IV are of the same order as those formerly used for the raw sugars. On the whole, the superiority of the formula method over the C-ratio method is plainly evident from the data in Tables IV and V, especially when it is considered that, for raw sugar products a t least, the formula method is of more general application, without a change in the factor used, than the C-ratio method, which must employ a different ratio for each geographical district or subdivision. T a b l e V-Summation PRODUCTS
of Errors on Basis of C h e m i c a l Ash C-RATIOMETHOD FORMULA METHOD Iiec. Pos. Total Yen. Pos. Total WITH SUCROSE
Cuban blackstraps Porto Rican blackstraps First and second molasses Cane sirups Filtered sirups Unfiltered sirups Final sirups (XI Final sirups CY) Final sirups (miscellaneous) Total Cuban blackstraps Porto Rican blackstraps First and second molasses Cane sirups Filtered sirups Unfiltered sirups Final sirups (X) Final sirups (Y) Final sirups (miscellaneous) Total
5.31 0.52 1.00 1.07 1.76 0.39 3.67 5.04 0 24
6.18 0.48 0.90 0.63 1.46 0.41 3.75 4.50 0.46
19.00
18.77
4.88 0.46 0.95 1.07 1.84 0.42 3.20 4.87 0.31
5.77 0.48 0.77 0.66 1.59 0 52 3.45 4.49 0,5S
__------
__
18 00
11.49 1.00 1.90 1.70 3.22 0.80 7.42 9.54 0.70
4.98 0.39 0.36 1.49 0.72 0.29 2.55 3.51 0.43
1.39 0.67 0 99 0.30 0.85 0.29 2.56 2.63 0.43
6.37 1.06 1.35 1.79 1.57 0.58 5.11 6.14 0.86
----
37.77
14.72 1 0 . 1 1 2 4 . 8 3 WITHOUT SCCROSE 10.65 3.73 1.76 5.49 0.20 0.94 0.87 1.07 1.72 0.43 0.85 1.28 1.73 3.28 0.00 3.28 3.43 0.98 1.34 2.32 0.94 0.30 0 . 3 1 0.61 2.12 2.40 4.52 6.65 9.36 2.77 2.31 5.08 0.89 0.52 0.55 1,07
-- --
_-
--
_-
18 31
14 33
IO 39
24 72
36 31
With some classes of products the C-ratio method has given about as good results as the formula method. For instance, in the case of the Porto Rican blackstraps, with and without sucrose, the individual as well as the total deviations are approximately the same for both methods. This is due to the fact that there were only 10 samples available and their C ratios happened to be close together. The same reasoning applies to the miscellaneous final sirups. The shortcomings of the formula method for cane sirups, under the experimental conditions, have already been discussed, and it has been shown how this difficulty may be overcome. Aside from these exceptions, which are more apparent than real, however, the formula method is undoubtedly preferable to the C-ratio method on account of its greater accuracy and wider applicability. From the work recorded here it would appear t h a t even with the conductometric formula method it would be necessary for each refinery to determine appropriate factors for each class of materials, from melt and affination sirup through to the final products. I n practice, some chemists may prefer to adopt such a course. If the cause of the variations in the factor of the correction formula can be discovered, however, it may be possible t o develop a more general formula, which would apply t o all products of the raw sugar factory as well as those of the refinery. It has already been mentioned that when the conductance determinations are made a t low concentration of total solids the principal factor affecting the ratio between ash and specific conductance is the relative proportion of the various anions present in the solution. This effect has been eliminated by a second conductance determination in the presence of hydrochloric acid and the application of an appropriate correction formula. But it has been shown in this paper that with refinery products this correction formula does not hold any more, except by changing the factor by which the corrective expression must be multiplied. A clue to the probable primary cause of the discrepancies is furnished by the conductometric titrations on raw sugars, with both acid and alkali. The raw sugar curves based on these results (6) showed large differences on the acid side but practically none on the alkaline side. However, potas-
35
sium chloride solution with added sucrose gave an alkali displacement curve which was quite different from the curves found for raw sugars. The initial conductances of the two raw sugars and of the potassium chloride-sucrose mixture were about the same. But the addition of 5 nil. of 0.25 N potassium hydroxide solution increased the specific conductance of potassium chloride solution by 0.000695, while the increase for the raw sugars was only 0.000593 and 0.000614. It is plausible that treatment of sugar products with boneblack eliminates not only weak organic acids but also certain weak bases. If this is so, it would be expected t h a t the displacement curves obtained with alkali would be steeper in the case of boneblack-treated products than for similar raw sugar products. This seems to be actually the case. For instance, a filtered refiner’s sirup containing 7.85 per cent of ash by the chemical method gave with 5 ml. of 0.25 N potassium hydroxide added to 200 ml. of the sirup solution an increase in the specific conductance of 0,000864, and a Cuban blackstrap of the same corrected initial conductance, but with an ash content of 8.82 per cent. gave an increase in specific conductance of only 0.000711, that is, 0.000153 less than the filtered sirup. Similarly, a final refinery sirup with 8.40 per cent ash gave an increase of 0.000769, and a Cuban blackstrap of the same initial conductance and with 9.04 per cent ash gave an increase of 0.000661, or 0.000108 less than the refinery sirup. The difference was smaller than that between a filtered sirup and a Cuban blackstrap, exactly in accordance with the theory. It may be possible to explain the differences in the correction factors for refinery products on the one hand and those for raw sugar products on the other on the basis of these considerations. For this reason, conductometric titrations with alkali are now being run on all the materials used in this investigation of which a sufficient quantity for a sample is still available. The same question will also be studied in another way. Samples of blackstraps will be treated with boneblack, and both the untreated and the treated samples will be subjected to a complete conductometric analysis. In this way it is hoped to establish a second correction which will yield a formula applicable to all products, whether treated with boneblack or not. It is possible that the discrepancies which still remain for materials of the same class, be it raw sugar or refinery products, may also be reduced by such a second correction based on alkali titration, because in some instances the relative proportion of the cations may not be as similar as was found in the case of raw sugars. Acknowledgment The writers are indebted to the following individuals and firms for the samples used in this work: AI. 0. Woolfley and C. C. Kesler, of Penick and Ford, Ltd., Inc., for cane sirups and first and second molasses; Czarnikow Rionda Company, Lom-ry and Company, and Augustus Wedderburn for Cuban blackstraps; N. Fuad, of the Sulomoline Company, for Porto Rican blackstraps; and officials and chemists of various refineries for their products. T. B. Wayne has taken a particular interest in these investigations, and his many valuable suggestions are gratefully acknowledged. Literature Cited (1) Honig, Arch. Surkerind , 36, 709 (1927). (2) Lunden, Z Ver deuf Zucker-Ind , 7 6 , 763 (1925); 76, 610 (1926) (3) Sandera, Z. Zuckerind. cechoslovak R e p , 61, 603 (1927). (4) Spengler and Toedt, Z. Ve7. deut Z u c k e r r n d , 78, 1 (1928). (6) Zerban, J. Assocn. O&cral Agr Chem , 4, 444 (1921) (6) Zerban and Sattler, Facts About Sugar, 21, 1158 (1926) (7) Zerban and Sattler, Ibrd., 2 2 , 990 (1927). (8) Zerban and Sattler, I b i d . , 18, 686, 713 (1928).
