Dec., 1913
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
993
of this test with t h a t of other methods in vogue. For this purpose three syrups, A, B, a n d C, were chosen. A, a light-colored syrup of high quality, a n d B, a mixture of several pure maple syrups, were kindly donated b y Mr. John H. Grimm, of Montreal, while C was a syrup made a t Macdonald College in t h e season of 1913. These were diluted with water a n d boiled t o 219’ F., after which their specific gravities a t 60’ F. were: A, 1.325; B, 1.320; C, 1.318. Cane-sugar syrups of t h e same specific gravities were prepared from granulated sugar a n d mixtures of the cane a n d maple syrups made up a n d analyzed. T h e following determinations were made upon each of t h e mixtures: ( I ) Total ash by ignition in a n electric muffle a t a low red heat (600-6 50’ C.). (2) Insoluble ash.’ SUMMARY AND CONCLUSIONS (3) Soluble ash b y difference. I n t w o series of baking tests of flour made from three (4) Alkalinity of insoluble ash.’ varieties of wheat, acid-extract of bran, water-extract, ( 5 ) Alkalinity of soluble ash.1 acid-extract neutralized, a n d dilute acid, were used t o (6) Conductivity value, i. e., IOO,OOO times t h e spereplace a p a r t of t h e water necessary t o make t h e dough. cific conductivity a t 2 j o c. of a mixture of one volume I n general, t h e acid-extract produced larger loaves syrup with t w o volumes of water.2 of bread (from 6 per cent t o 2 0 per cent increase in ( 7 ) Canadian lead number.3 volume) of a better color a n d texture t h a n t h e check (8) Winton lead number. I n Syrups B and C this loaf, or those in which other extracts were used. T h e determination was made upon 2 5 grams of syrup a s water-extract produced loaves somewhat larger t h a n originally directed b y W i n t ~ nt,h~e blank being treated t h e check loaves. T h e dilute acid gave a loaf of dewith acetic acid as directed b y Bryan.5 creased volume a n d very poor texture. I n Syrup A , however, t h e determination was made Analyses of acid- a n d water-extracts show t h e presupon the quantity of syrup (38.462 grams) containing ence of 0.464 gram P205 a n d 0.163 gram Pzos, respec2 5 grams of dry matter, t h e procedure prescribed by tively, in I O O cc. extract. Experiments made t o show t h e stimulating effect t h e Canadian standard of purity for maple syrup.6 ( 9 ) Ross’s modified Winton number.7 of acid-extract on yeast were not convincing. It is This determination also was made on 2 5 grams of thought the presence of both acid a n d soluble salts syrup in Syrups B a n d C, but upon 38.462 grams in makes the gluten more coherent. I n general t h e better t h e flour, t h a t is t h e stronger syrup A. (IO) Sy lead value.’ Weight of lead precipitated t h e gluten, t h e more marked is t h e improvement by from normal lead acetate by I O O cc. of syrup. use of acid-extract; b u t all samples of flour show greater T h e results obtained are shown in Tables I, 11, a n d or lesser improvement. T h e inner portions of the loaves of bread made with 111. I n Tables IV, V, a n d VI t h e actual percentage acid-extract show no greater a m o u n t of water-soluble of maple syrup in each mixture is compared with t h e acid reacting material t h a n t h e average of home-made, “estimated percentages” derived from t h e ratios of t h e various values in the mixture t o those in the pure or bakers’ bread. I n conclusion, t h e writer wishes t o acknowledge his syrup. indebtedness t o L. M. Thomas, of t h e Division of Grain E F F E C T S P R O D U C E D U P O N T H E V A R I O U S D A T A B Y P R O Standardization, Bureau of Plant Industry, U. S. Dept. GRESSIVE DILUTION WITH SCCROSE SYRUP of Agriculture, for his cooperation in making t h e baking It will be noted t h a t the ratios of the weights a n d tests, scoring the bread a n d for making t h e photographs also those of t h e alkalinities of the soluble ash t o t h e t h a t are used in this report. insoluble ash remain nearly constant down t o the j o NORTH DAKOTAAGRICULTURAL COLLEGE per cent mixture. I n mixtures containing less t h a n jo per cent. of maple syrup, these ratios fluctuate THE ANALYSIS OF MAPLE PRODUCTS, I1 greatly. These fluctuations are doubtless due t o t h e A Comparative Study of the Delicacy of Methods2
loaf volume a n d texture, and, t o a lesser degree, the color. I n view of t h e fact t h a t in the larger number of baking tests the acid-extract had a greater influence t h a n t h e water-extract t o increase loaf volume a n d t o improve the color a n d texture, t h e question naturally arises as t o whether t h e improvement is due t o t h e stimulating effect of acid, or phosphate, or other constituent of t h e extract on t h e yeast; or t o some other factor. Experiments undertaken t o determine t h e stimulating effect of acid-extract on yeast were not convincing. A possible explanation is t h a t t h e gluten may have become more coherent in t h e presence of acid a n d soluble’ salts (particularly phosphates) as is suggested b y Wood.’ At a n y rate, t h e baking tests show clearly t h a t it is not acid alone, b u t acid plus extractive material t h a t gives t h e best results.
By J.
F. SNELLA N D . J . M. SCOTT
I n studying t h e usefulness of t h e electrical conductivity test3 for the detection of adulteration in maple syrup it appeared desirable t o compare t h e delicacy 1 T. B. Wood, Jour. Agr. Sci., 2, 267 (1907); Abstract i n J . SOC. Chem. I n d . . 27, 175 (1908). 2 Paper presented a t t h e 48th Meeting of t h e A. C. S., Rochester, September 8-12, 1913. 3 Snell, THIS JOURNAL, 5, 740 (1913).
1 Jones, Vermont Agr. Expt. S t a . , 1 8 f h A n n . Refit., 1904-5, 321; Bryan Bur. Chem., U. S. Dept. Agr., BUZZ. 134, 17 (1910); McGill, Lab. Inland Revenue Dept., Ottawa, Bull. 228, 5 (1911). 2 Snell, loc. c i f . 3 McGill, LOG. cit. 4 Winton and Kreider, J. A m . Chem. SOL.,28, 1204 (1906). 6 Bryan, Zoc. c i f . 6 Canadian Order-in-Council, G, 994, Nov. 8, 1911; McGill. Lab. Inland Rev. Dept., Bull. 238, 5 (1911). 7 Ross, Bur. Chem., U. S. Dept. Agr., Circ. 68, 8 (1910). Sy, J. F r a n k . Ins!., Dec , 1908, page 68 of reprint.
T H E JOCRNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
994
TABLE I-h{APLE Per cent Per cent maple total syrup ash 100 90 80 70 60 50 40 30 20 10
Per cent insoluble ash
Per cent sol. ash
Sol. ash: Insol. ash
0.45 0.38 0.35 0.26 0.25 0.20 0.14 0.14 0.06 0.02
0.69 0.70 0.51 0.42 0.46 0.48 0.18 0.06 0.09 0.07
1.53 1.89 I .46 1.62 1.84 2.40 1.29 0.43 1.50 3.50
1.14 1.08 0.86 0.68 0.71 0.68 0.32 0.20 0.15 0.09
* Winton
Alkalinity Alkalinity insol. ash sol. ash 56 54 46 38 36 31 20 22 16 10
and Ross methods on 25 grams d r y sugar
4i 52 42 36 31 26 20 12 14 4
SYRUP
Vol.
j,
No.
A
Alk. sol. ash: Alk. insol. ash
Conductivity value
0.84 0.96 0.91 0.92 0.86 0.84 1 .00 0.55 0.87 0.40
136 126 115 101 90 i8 65 50 35 20
Canadian lead number
Modified Winton* lead no.
Modified Ross* lead no.
1.46 1.44 1.23 1.18 1.04 0,i2 0.55 0.30 0.16 0.00
1.78 1.69 1.60 1.50 1.39 1.33 1.23 1.04 0.80 0.44
0.342 0.309 0.2i3 0.229 0.194 0.179 0.104 0.075 0.052 0.020
Winton* lead number
Ross* lead number 1.72 1.64 1.48 1.34 1.16 1.08 0.82 0.66 0.37 0.10
Sy lead value 0.460 0.378 0,296 0.259 0.239 0,177 0,128 O.Oi4 0,050 0.022
2.26 l.il 1.58 1.38 1.10 0.iO 0.36 0.14 turbidity only faint turbidity
Sy lead value
38.462 grams syrup.
=
TABLE11-MAPLE SYRUPB Per cent Per cent total maple ash syrup 0.92 100 0.80 90 0.71 80 0.62 70 60 0.55 0.49 50 40 0.38 0.32 30 0.22 20 10 0.08
* Winton
Per cent insoluble ash
Per cent water-sol ash
Sol. ash: Insol. ash
0.40 0.37 0.25 0.26 0.22 0.20 0.12 0.09 0.06 0.02
0.52 0.43 0.46 0.36 0.33 0.29 0.26 0.23 0.16 0.06
1.30 1.16 1.84 1.38 1.50 1.45 2.17 2.56 2.67 3.00
Alk. sol. Conducash: Alk. tivity insol. ash value 0.80 170 0.77 147 0.72 144 0.73 126 0.67 109 0.74 95 7i 1 .oo 1.21 58 1.17 4i 0.90 24
Blkalinity Alkalinity insol. ash sol. ash 65 62 57 52 46 38 26 19 12 10
52 48 41 38 31 28 26 23 14 9
Canadian lead number 3.18 2.67 2.12 1.81 1.60 1.06 0.74 0.31 turbidity only no turbidity
1.46 1.34 1.19 1.03 0.89 0.73 0.54 0.38 0.23 0.11
and Ross methods on 25 grams syrup.
TABLE 111-MAPLE SYRUP C Per cent Per cent total maple ash syrup 0.70 100 0.63 90 0.54 80 0.47 70 0.39 60 0 .34 50 0.31 40 0.23 30 0.17 20 0.06 10
Per cent insol. ash
Per cent sol. ash
0.27 0.24 0.21 0.21 0.18 0.14 0.12 0.09 0.06 0.02
0.43 0.39 0.33 0.26 0.21 0.20 0.19 0.14 0.11 0.04
,
TABLE IV- -MAPLE S Y R U P A. Actual per cent maple syrup 90 80
io 60 50 40 30 20 10
Estimated from total ash
Estimated from insol. ash
94.7 75.4 59.6 62.3 59.6 28.1 17.5 13.2 7.9
84.4 i I .8 57.8 55.5 44.4 31.1 31.1 13.3 4.4
Actual per cent maple syrup 90 80
Estimated from total aih 8T.6
io
67.4 59.8 53.3 41.3 34.8 23.9 8.i
60 50 40 30 20 10
--
i1.2
SYRUP
Estimated from insol. ash 92.5 62.5 65.0 55.0 50.0 30.0 22.5 15.0 5.0
1.59 1.62 1.57 1.24 1.17 1.43 1.58 1.56 1.83 2.00
101.4 i3.9 60.9 66.6 69.6 26.1 8.7 13.0 10.1
B
Alkalinity Alkalinity insol. ash sol. ash 48 45 44 38 30 26 20 18 14 6
ESTIMATED MAPLE
Estimated from sol. ash
--
TABLE Y-31APLE
Sol. ash: Insol. ash
Alk. sol. ash: Alk insol. ash
Conductivity value
0.83 0.84 0.80 0.82 0.93 0.92 1.os 0.94 0.86 1 .00
128 1 17 10; 96 85
40 38 35 31 28 24 21 17 12 6
SYRUP
io 59 47 31 18
Canadian lead number 2.02 1.80 1.38 1.09 0.64 0.37 0.24 0.14 faint turbidity n o turbidity
Winton lead number
Ross lead number
1.34 1.28 1.10 0.98 0.74 0.67 0.56 0.44 0.38 0.18
1.49 1.37 1.21 1.07 0.86 0.79 0.66 0.52 0.31 0.23
Sy lead value 0.415 0.351 0.308 0.265 0.166 0.126 0.072 0.058 0.032 faint turbidity
CONTEST CALCULATED FROM DETERMINATIONS GIVEN IN TABLE I
Estimated from alk. insol. ash
Estimated from alk. sol. ash
96.4 82.1 67.9 64.3 55.4 35.7 39.3 28.6 17.9
110.6 89.4 76.6 66.0 55.3 42.6 25.5 29.8 8.5
Estimated from conductivity 92.6 84 6 74.3 66.2 57.4 47.8 36.8 25, 7 14.7
Estimated from Canadian lead no. 75.7 69.9 61.1 48.7 31 .O 15.9 6.2
....
....
Estimated f r o m modified Winton lead no.
Estimated from modified Ross lead no.
98.6 84.2 80.8 71.2 49.3 3i.i 20.5 11.0 0.0
94.9 89.9 84.3 78.1 74.8 69,i 58.4 44.9 24.7
Estimated from S y lead value 90.3 19.8 67.0 56.7 52.3 30.4 22.0 15.2 5.8
ESTIMATED MAPLE SYRUP CONTENT CALCULATED FROM DETERMINATIONS GIVEN I N TABLE11 Estimated from sol. ash
Estimated from alk. insol. ash
82,i 88.5 69.2 63.5 55.8 50.0 44.2 30.8 11.5
95.4 8i.i 80.0 70.8 58.5 40.0 29.2 18.5 15.4
Estimated from alk. sol. ash 92.3 i8.8 i3.1 59.6 53.9 50.0 44.2 26.9 17.3
Estimated from conductivity 86.5 84.7 74.1 64.1 55.9 45.3 34.1 27.6 14. I
Estimated from Canadian lead no. 83.9 66.i 56.9 50.3 33.3 23.3 9.7
....
Estimated Estimated from Winton from Ross lead no. lead no. 91.8 95.3 81.5 86.0 70.5 77.9 67.4 61 . O 50.0 62.8 37.0 4i.7 26.0 38.4 15.8 21.5 7.5 5.8
Estimated from S y lead value 82.2 64.3 56.3 52 0 38.5 27.8 16. I 10.9 4.8
12
T H E JOUR-V-4L O F I i V D r S T R I d L - 4 S D E-VGIiVEERI-VG C H E M I S T R Y
Dec., I913
TABLEVI-MAPLE SYRUPC .
ESTIMATED MAPLES Y R ~COSTENT P FROM DETERMIXATIONS GIVENI N TABLEI11
Actual per cent maple syrup
Estimated f r o m total ash
Estimated f r o m insol. ash
Estimated f r o m sol. ash
Estimated from alk. insol. a s h
Estimated f r o m alk. sol. ash
Estimated f r o m con. ductivity
90 80
90.0
TO
67. 1 55.7 48.6 44.3 32.9 24.3 8.6
88.9 77.8 77.8 66.7 51.9 44.4 33.3 22.2 7.4
90.7 76.7 60.5 48.8 46.5 44.2 32.6 25.6 9.3
93.7 91.7 79.2 62.5 54.2 41.i 37.5 29.2 12.5
95.0 87.5 77.5 70.0 60.0 52.5 42.5 30.0 15.0
91.4 83.6 75 0 66.4 54.; 46.1 36.7 24.2 14.1
60 50 40 30 20 10
-1 -1 . 1
greater influence of experimental errors in t h e ash determinations in mixtures of low, as compared with those of high, maple content. I n t h e I O per cent mixtures t h e actual quantity of insoluble ash weighed was in each instance one milligram, while t h e quantities of t e n t h normal acid used were 0.20, 0.4j a n d 0.30 cc., respectively, in t h e soluble ash of Syrups A, B, a n d C , and o.jo, 0 . j o and 0.30 cc. in t h e insoluble ash. A similar variability is noticeable in most of t h e other values for t h e mixtures of low maple content. T h e true Winton a n d Ross lead numbers (Syrups B and C) and t h e conductivity value come nearest t o decreasing proportionally t o the maple content. The conductivity value gives estimated results a little higher t h a n the actual. with t h e single exception of t h e 9 0 per cent mixture in case of Syrup B. T h a t this exception is not due t o experimental error is evidenced not only b y t h e fact t h a t repetition of t h e measurement on this syrup confirmed t h e result a t first obtained, b u t t h a t in t h e case of four other syrups, 90 per cent mixtures gave estimated values of 86.6, 87.0, 87.2, and 87.3. I n this respect, accordingly, Syrups A and C appear exceptional rather t h a n Syrup B. Accordingly. small adulteration with cane sugar appears often t o have somewhat more t h a n i t s proportional effect on conductivity, while greater adulteration has a l ~ a y sless t h a n i t s proportional effect.
Actual per cent maple syrup
TVin t on lead no.
100 90 80
1.TI
TO 60 50 40 30 20 10
1 56 1.30 1 . I4 I .03 0.8i5 0,605 0,425 0.265 0.09
Maple content estimated from Winton lead no.
Ross lead no.
Maple content estimated from Ross lead no.
91.2 ,~>,7 66.7 60.2 51.2 35.4 24.9 15.5 5.3
2.01 1.85 1.63 1.41 1.40 1.19 0.825 0.76 0.43 0.135
91.8 81.1 70.1 69,7 59.2 41 . 0 3T.8 21.4 6.7
-_
995
....
The Ross lead number when determined b y t h e original method (Syrups B and C) does not decrease as rapidly as t h e actual maple syrup content. ( I n t h e case of Syrup A where t h e determinations are made on a quantity of syrup equivalent t o 2 j grams of dry sugar t h e results obtained are high throughout and further from t h e actual proportions of maple syrup t h a n are those obtained without t h e use of potassium sulfate.) These results-particularly those on Syrup B (Tables I1 and V)-are not in agreement with Dr. Ross’s experience, a n d in correspondence with us he
1
Estimated from Canadian lead no.
Estimated from Winton lead no.
Estimated f r o m Ross lead no.
Estimated from S y lead value
95,s 82.1 T3.1 55.2 50.0 41.8 32.8 28.4 13.4
91.9 81.2 71 8 57.7 53.0 44.3 34.9 20.8 15.4
84.6 T4.2 63.9 40.0 30.4 17.3 14.0
89.1 68.3 54.0 31.7 18.3 11.9 6.9 ‘
.... ....
--
, , I
....
suggested t h a t our high results might be due t o our neglect t o observe his caution t o use only freshly boiled distilled water in diluting t h e syrup. Unfortunately we were not able t o test this point with Syrup B as our material was exhausted. We have, however, made a series of experiments on some of t h e mixtures of Syrup C, t h e results of which are given in Table V I I . K O TABLEVII-COMPARISON OF Ross LEADSUMBERS O N MIXTURES OF SYRCP C , USINGFRESHLY BOILEDA N D UXBOILED WATER Actual Ross lead Ross lead per cent maple syrup 100 80 50 20
number with freshly boiled water 1 .42 1.17 0.78 0.32
Calculated per cent maple syrup ..
.
82.0 54.9 22.5
number with unboiled distilled water 1.49 1.21 0.i9 0.31
Calculated per cent maple s y r u p
. . 81.2 53.0 20 8
difference of consequence was observed due t o t h e boiling of the water. In order t o make a further study of t h e Winton and Ross methods we prepared two composite samples ( D 2nd E) from I O O pure syrups made in t h e season of 1913. The syrups from which these composites were made were obtained directly from t h e sugar bushes of Quebec and Ontario by graduate representatives of t h e College, so t h a t there can be no doubt as t o their purity. lfixtures of these syrups with cane syrup were made u p and t h e ROSS 2nd K i n t o n lead determinations made upon each,
Winton lead no. 1.635 1.325 1.18 1.06 0.825 0.645 0.46 0.29 0.145 0.060
Maple content estimated from Ross lead no.
Maple content estimated from \\‘inton lead no.
Koss lead no.
....
2 I55
....
81 . 0
1 .94 1.75 1,625 1.355 1.12 0.905 0 i2 0.445 0.190
90.0 81.2 T5 .4 62.9 52.0 42.0 33 4
i2.2
64.8 50.5 39.4 28.1 17.7 8.9 3.i
20.i
8.8
freshly boiled water being used in t h e Ross method. As will be seen from t h e results which are tabulated in Table T-111, t h e Ross method gives estimated results much cioser t o t h e actual maple content t h a n does t h e Winton method. Especially is this t h e case in regard t o Syrup E . I n most instances t h e estimated results with t h e T i n t o n method are lower t h a n the actual maple content, while on t h e other hand the Ross method gives results slightly higher t h a n t h e actual. The Canadian lead number drops off much more rapidly t h a n t h e actual maple syrup percentage a n d
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
996
'
vanishes in t h e three series a t a maple content of 20 per cent. This fact gives t h e Canadian method a distinct advantage as far as t h e detection of small adulteration is concerned, b u t renders it useless for distinguishing compound maple syrups containing a small proportion of maple from imitation syrups containing none. Moreover, t h e advantage of t h e Canadian method for t h e former purpose is somewhat offset b y t h e great variability of t h e Canadian lead number in genuine maple syrups. I n its investigation of some 4 5 0 Canadian syrups of t h e season of 1 9 1 I , obtained directly from t h e makers accompanied b y a declaration of genuineness,' t h e Laboratory of t h e Inland Revenue Department found twelve syrups with values below t h a t adopted in t h e standard, ziz., 1.70. Six samples yielded lead values of over 4.50, a n d of these three were above 5.00. I n a n uncompleted investigation of I z j genuine Canadian syrups of t h e season of 1 9 1 3 we have found even a greater variation in t h e Canadian lead number, 9 samples having values above 4 . 5 0 , 8 of which are also above 5.00. As will be seen b y referring t o t h e Canadian lead numbers in Table 11, a syrup of high lead value may be adulterated with a comparatively large proportion of cane sugar without falling below t h e Canadian standard. Syrups A a n d C, however, with original lead values of 2 . 2 6 a n d 2.02, respectively, have already reached t h e limit of t h e standard when t h e adulteration amounts t o I O per cent. T h e Sy lead number, like t h e Canadian, drops off more rapidly t h a n t h e maple content. B u t i t does not show this propensity t o t h e same degree as t h e Canadian value. We are unable t o see any advantage in Sy's method over t h e other methods which would compensate for t h e extra time and labor involved in making t h e determination. RANGE OF VARIATION I N G E N U I N E S Y R U P S
The delicacy of a n y method of detecting adulteration of maple syrup with pure sucrose obviously depends upon: ( I ) The limits of natural variation of t h e value in question in genuine syrups. ( 2 ) The r a t e a t which t h e value falls off as t h e proportion of genuine syrup is decreased. AS we have seen, t h e Canadian lead value excels in t h e second point b u t not in t h e first. T h e range of variation of t h e differe n t values may readily be seen from Table I X , which SYRUPS.
.
OF V A R I O U S
EXPRESSED IN
ANALYTICAL VALUES
COMPARATIVE PRECISION OF LEAD METHODS
The Laboratory of t h e Canadian Inland Revenue, which originated t h e Canadian lead method, admits t h a t t h e Winton method gives more precise results, i. e., closer duplicates, t h a n can be obtained with t h e Canadian method. Our own experience is t o t h e same effect. It occurred t o the authors t h a t i t might be possible to combine the advantages of these two methods by using t h e same proportion of lead subacetate solution as in t h e Canadian method, and determining t h e amount of residual lead in solution as i n the Winton method. Some experiments have been carried on in this connection, t h e results of which will be published in a subsequent paper. MODES O F WASHING PRECIPITATE
TABLEX-EFFBCT
OF VARIATIONS OF TEMPERATURE AND VOLUMEOF WASHWATER UPON THE C A N A D ~ A LEAD N NUMBER
Syrup I
IN
Lab. of the Inland Revenue Dept., Ottawa, Bull. 228 (191 l ) .
CANADIAN L E A D
Experiments have also been made upon t h e effect of temperature and volume of wash-water upon t h e weight of t h e lead subacetate precipitate as obtained b y t h e Canadian method. The results given in Table X clearly indicate t h a t wash waters of 80" and 100" C.
...
I
IN
METHOD
PERCENTAGE OF THE
shows percentage variation of t h e different values in t h e natural product as found b y Bryan, McGill, and ourselves. Bryan's figures were obtained from 4 8 1 samples of maple syrup representing all t h e mapleproducing states of t h e Union a n d the Province of Quebec. McGill's figures on t h e Canadian lead number are based upon analyses of 456 samples of Cana-
12
dian syrups; those on Winton lead number, total ash and malic acid upon a s t u d y of 4 7 , 1 1 5 and 4 5 2 of these samples, respectively. Our limits for the conductivity method are t h e result of measurements made upon over zoo syrups. It will be noticed t h a t t h e range is somewhat wider t h a n t h a t reported in t h e first paper of this series, viz. 82%. This is due t o t h e fact t h a t since t h e publication of t h e paper on electrical conductivity we have found syrups which gave conductivity values above t h e maximum previously obtained ( z o o ) and which from our present information we must regard as genuine. We have, however, found none below t h e minimum reported ( 1 1 0 ) . Our figures for the other values are based upon an uncompleted investigation of 1 2 5 samples of Canadian syrup of the season of 1913 a n d are t o be regarded a s merely tentative. When t h e investigation is completed t h e range of some of t h e values may prove t o be narrower t h a n here reported. From t h e figures given in Table I X i t is evident t h a t t h e conductivity value shows t h e narrowest limits of variation of any of the data.
Total GENUINE MAPLE MINIMUM Temp. of wash water 80' C. 50 cc. Total Winton Malic acid Canadian Conductiv. . 4.56 Investigator ash lead no. value lead no. ity valiie Ist time. ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' 4.52 147 151(a) 4.52 ... Bryan.. . . . . . . . . . 2nd t i m e . . . . . . . . . . . . . . . . . . . 4 . 6 8 287 380 McGill, ........... 100 127(b) 4.80 329 33 1 109 Snell and Scott.. .... 125 190 (a) Original Winton method. ( b ) Modified Average at 80" . . . . . . . . . . . . . . . . 4 . 6 4
TABLE IX-RANGE
Vol. 5, No.
1000
quantity of wash water@ 100 cc.
4.29 4.32 4.63 4.60
150 cc. 4.20 4.62 4.12 4.21
4.46
4.29
4.37
-
Average
-
4.46
c.
1st time.. . . . . . . . . . . . . . . . . . . .4 . 7 7 4.66 2nd t i m e . . . . . . . . . . . . . . . . . . . . 4 . 8 4
...
Average at 100'.
..............
4.76
4.26 4.35
4.70 4.50 4.36 4.42
_ .
_ .
4.33
4.50
....
Average ...................... 4.70 4.40 4.40 Max. deviation.. . . . . . . . . . . . . . 0 . 1 8 0.23 0.30 (a) Applied in five equal portions in every instance.
4.53
Dec., 1913
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y S y r u p I1
THE B L A N K I N T H E WIh-TON M E T H O D
T o t a l q u a n t i t y of wash-water(a) 7
T e m p . of wash water 80’ C . 50 cc. 1st t i m e . , . . . . . . . . . . . . . . . . . . . .
2.83 2.92 2.95 2.98
2nd t i m e , . . . . . . . . . . . . . . . . . . ~
Average a t 80’
.............
100 cc.
150 cc.
2.40 2.54 2 , 74 2.75
2.58 2.69 2.75 2.79
~
Average
-
2.92
2.61
2.70
2.93 2.82 2.82 2.98
2.72 2.iO 2.81 2.76
2.51 2.65 2.43 2.54
2.74
1000 c .
1st t i m e . .
..................
2nd t i m e . . . . . . . . . . . . . . . . . . . .
__
~
__
Average a t 10Oo... . . . . . . . . . . . . 2 . 8 9
2.75
2.53
Average. . . . . . . Max. d e v i a t i o n . . . . . . . . . . . . . .
2.68 0.28
2.62 0.19
2.91 0.09
2.72
I n making the determination of lead in the blank for t h e Winton method, Bryan recommends the addition of acetic acid t o the lead subacetate solution t o prevent formation of a precipitate upon the addition of water, “as pure sugar would do.”l Upon making determinations in duplicate on two blanks, one treated with acetic acid, the other with z j grams cane sugar syrup, we found t h a t smaller amounts of lead were held in solution by t h e cane sugar t h a n by the acetic acid. This was t h e case, whether the determinations were made immediately upon the unfiltered blank or upon the settled (3 hours) a n d filtered blank, as will be seen from the figures of Table X I I . It would TABLEXII-EXPERIMEhT
( a ) Applied in five equal portions in every instance.
MODES O F R E D U C T I O S O F LEAD XCMBERS
O h \\‘iNTOh
BLA~K
Weight of lead sulfate precipitate
give identical results. Higher results are obtained ‘with 50 cc. of wash water (applied in five portions) t h a n with I O O cc. or I j o cc. There is no material difference between the results obtained with I O O cc. o of wash water. a n d with ~ j cc. hlATTER
997
TO D R Y
BASIS
I n t h e investigation made b y the Laboratory of t h e Inland Revenue Department preliminary t o t h e setting of standards, t h e Canadian a n d Winton lead determinations were made upon fixed quantities of syrup (j grams a n d z 5 grams, respectively) a n d t h e results calculated t o a dry m a t t e r basis. T h e standards, however, prescribe t h e use of a quantity of syrup equivalent t o t h e same fixed quantity of d r y matter, i. e . , 5 grams a n d 2 5 grams of dry matter, respectively. We have made a comparison of results obtained directly b y the methods of t h e Canadian standard with those obtained b y calculation from the determinations on the wet basis. As will be seen from Table X I ,
Immediately unfiltered 0 . 1593 Acetic acid used a s clarifier in b l a n k . . . . . . . . 25 grams cane sugar s y r u p in b l a n k . . . . . . . . . . . 0 . 1 5 7 1
A t end of 3 hours filtered 0.1600 0.1558
seem t o be more rational t o make t h e Winton blank in the presence of cane sugar syrup rather t h a n with acetic acid, as in this way we should approximate more closely t o the conditions obtaining in the determinations upon maple syrup. S U h1 MA R Y
T h e rates a t which the conductivity value, ash d a t a a n d various lead values fall off a s maple syrup is diluted with cane sugar syrup are determined for three samples of maple syrup. 2 . The range of variation of these data in genuine syrups is studied with reference t o the work of Bryan a n d h’IcGill, as well as t o our own work. 3. The Canadian lead value shows the most rapid falling off. 4. The conductivity value shows the narrowest range. TABLEXI-COMPARISON OF LEAD XUMBERSO N DRY BASIS,ACTUAL j. The Winton lead method gives better agreement A N D CALCULATED of duplicates t h a n t h e Canadian method. Canadian lead method Winton lead method 6 . I n t h e Canadian method no material difference Actual Actual Calculated DifferSyrup Calculated Differis obtained by washing the precipitate \\,ith water number lead no. lead no. ence lead no. lead n3. ence a t 8 0 ” a n d 100’ C. Practically identical results are 1 1.80 1.36 0.44 1.35 1.53 0.18 2 3.20 2.95 0.25 1.96 2.11 0.15 obtained with I O O cc. a n d I j o cc. wash water, but higher 3 3.02 2.63 0.39 1.98 2.20 0.22 results with jo CC. 4 2.86 2.51 0.35 2.01 2.16 0.1.5 7 . Results obtained in the Canadian method, using t h e quantity of syrup containing j grams of dry matter, Average, 0 . 3 6 0.18 are higher t h a n those obtained with use of 5 grams of with t h e Canadian method the results obtained by syrup a n d calculated t o t h e dry basis. On the other calculation t o a dry basis are lower t h a n those de- hand, in t h e modified Winton method, prescribed in termined directly upon t h e dry basis, the average t h e Canadian standards, lower results are obtained difference on t h e four syrups being 0.36. With the with t h e use of t h e quantity of syrup containing z 5 Winton method, on t h e other hand, the calculated re- grams dry matter t h a n when 2 j grams syrup are used sults are uniformly higher t h a n those directly deter- a n d t h e results calculated to t h e dry basis. mined, the average difference in this case being 0.18. 8. T h e use of cane-sugar syrup instead of acetic All results given are the average of closely agreeing acid in t h e Winton blank is suggested. duplicates. I t would appear, therefore, t h a t material ( T h e expenses of this investigation were defrayed differences exist between the results obtained, on the out of the grant of the Dominion Government for the one hand, by determination upon a fixed quantity of advancement of agriculture, I 9 I 2.) syrup a n d calculation t o a dry basis and, on the other MACDONALD COLLEGE hand, by direct determination upon a definite quantity QuBBEC, CANADA of d r y matter, ’Bryan. h.CZ~., p. 18. L
~
I.
