June,
1920
T H E JOURRNAL O F 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
SERIESI11 ORIGINALJUICE Pectin. Per cent . . . . . . . . . . 1.62 ,Specific Gravity.. . . . . . . . . . 1,020 Acidity, Per cent. . . . . . . . . . 0 . 1 I 8 Sugar, Lhs. per G a l . . 4.25 Acid added, grams.. 7 Cooked t o ' F . . 221 13 Yield, 8 oz. glasses.. .Quality.. . . . . . . . . . . . . . . . . Firm and stiff
DILUTEDTO1.0 0.75 1.017 1.012 0.073 ... 4.25 4.25 15 20 221 221 13.5 13 Little soft Very good
-JUICE
...... ....... ........... ......
SERIES I V
1 Per cent Pectin Base with Increased Suzar
ORIGINAL
DILUTEDTO0.75 0.5 ... .5 1.5 1.5 1 . 2 1.008 11,007 1.006 1.017 1.012 0.25 0 . 2 1 0.176 0.132 0.113 8 5 Ibs. 5 Ibs. 5 lbs. 5 Ihs. 1 02. 1 02. 1 02. 1 0 2 . 1 0 2 . Acid added, t s p l . . 1 1 1 1 1 1 219 219 219 Cooked t o F.. . . . . . . . 219 219 219 1 8 . 5 18 17 Yield, 8 0 2 . glasses 16 18 28 Good Quality., Very firm Firm Deli- Soft Soft cate 1 Teaspoonful acid (made b y dissolving 1.5 Ibs. acid per gal. water) added t o each glass, rather than cooking with juice. Juice prepared by cooking pomace 2 hrs. with 0.5 02. acid for each lb. pomace. JUICE
Pectin, P y c e n t . , . . . . . .59 Volum e, tial. . . . . . . . . 1. s Specific Gravtty., , , 1.017 Acidity Per c e n t . . 0.25 Sugar a'dded, f;bs ...... 5 Ibs. ~
. .. .... .....
--JUICE
!. ?5
1.0 1.5
............
A s t h e result of these tests special attention should be called t o t h e fact t h a t , regardless of t h e per cent .of pectin in t h e juice used, t h e same amount of jelly was obtained. T h e amount of sugar which would produce t h e best quality of jelly for commercial industries was next determined. A series of tests was run with various amounts of sugar per gallon of apple juice of a 1.25 per cent pectin content. ANALYSISOF JUICE Specific G r a v i t y . . Acidity, Per cent.. Pectin, Per cent..
............ 1.021 . . . . . . . . . . . .0.43
.............
1.30
With this juice 2 , 3, 4, 5 , 6 , 7 , 8, 9, I O , and 1 1 lbs. of sugar were used for each gallon of juice. The jelly became more delicate and sweeter as t h e amount of sugar increased. T h e lot containing 5 lbs. of sugar per gallon of juice was selected as best in texture for commercial use, b u t t h e lot containing 6 lbs. was considered best in flavor. T h e 9 t o 1 1 lb. batches produced a fine, delicate jelly, which is more like homemade, b u t entirely too delicate for commercial use, a n d really too sweet t o be relished. Using as a base 1.25 per cent pectin with 5 lbs. of sugar per gallon, t h e following table which can be .applied t o a n apple juice has been worked out: SUGAR FOR APPLE JUICE-PECTINBASE Pectin Per cent
Sugar per Gallon of Apple Juice Lbs. Oz.
Pectin Per cent 1.25 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00 2.50 3.00
Sugar per Gallon of Apple Juice Lbs. Oz. 5.0 5.0 i:2 5.0 9.6 6.0
6.0 6.0
7.0 7.0 8.0
10.0 12.0
6:4 12.8 3.2 9.6
.. ..
..
Since these results have been obtained, there has also been found a relationship between t h e Brix hydrometer reading of juice made from apple pomace and t h e amount of sugar t o be added per gallon of juice. For every degree Brix, use a pound of sugar. For example, if t h e juice reads 5.6" Brix, use 5.6 Ibs. of sugar for every gallon. This will produce a fine, clear jelly, which is firm and will stand up under
559
almost a n y climatic conditions. A more delicate jelly can be made by increasing t h e sugar t o 1 . 2 5 lbs. per every degree Brix. T h e greater the amount of sugar t h e greater t h e yield. QUANTITATIVE DETERhIINATION O F PECTIN
T h e only test for pectin in use a t present is t h e alcohol precipitation method where t h e pectin is precipitated with alcohol, dissolved in water, evaporated t o dryness, dried, weighed, burned, and re-weighed, and the loss in weight expressed as pectin. Most methods call for a concentration of over 5 0 per cent alcohol in testing, b u t this is hardly sufficient as t h e sugars and other soluble substances are held in t h e concentrated mass of pectin precipitated. T h e author used I O cc. of filtered juice and ISO cc. of alcohol, adding t h e juice drop b y drop from a pipette, with vigorous stirring. It was filtered immediately, dissolved in boiling distilled water, evaporated t o dryness, heated 2 hrs. a t 70' C. in vaczto, weighed, ashed, and re-weighed. T h e loss in weight multiplied by I O equaled t h e per cent of pectin. It was not necessary t o let t h e precipitate stand a n y length-of time, as no further precipitate formed. T h e precipitate could be filtered through a Gooch crucible, thereby eliminating t h e dissolving and drying, often saving about 2 hrs. in handling. A physical indication of t h e amount and quality of t h e pectin present in t h e juice may be obtained by observing t h e precipitation of t h e pectin as t h e juice is slowly run into t h e alcohol where t h e proportion of I O cc. of juice t o from 1 5 0 t o 180 cc. alcohol is used. When t h e pectin amounts t o over one per cent it will gather in a cohesive gummy mass, b u t if t h e amount is less, t h e precipitate is flocculent and will not gather in a solid mass. A little care in observing this precipitation will give a rough b u t quick check on t h e juice t o be used. T h e results obtained b y using this quantitative method of determining pectin have been so concordant t h a t they have been successfully applied t o commercial jelly manufacturing, resulting in a n increased production and a n improved product. B y thus controlling t h e manufacturing of jelly from a pectin standpoint it is possible t o obtain a more uniform product t h a n the average jelly manufacturer secures. ACIDITY AND ACIDIMETRY OF SOILS. III-COMPARISON OF METHODS FOR DETERMINING LIME REQUIREMENTS OF SOILS WITH HYDROGEN ELECTRODE. IV-PROPOSED METHOD FOR DETERMINATION OF LIME REQUIREMENTS O F SOILS By Henry G . Knight OKLAHOMA AGRICULTURAL AND MECHANICAL COLLEGE,STILLWATER, OKLAHOMA Received October 14, 1919
P A R T I11
Through t h e courtesy of Mr. J. W. Ames of the Ohio Agricultural Experiment Station fifteen samples of soil were obtained from a number of variously treated plots from one of t h e fertility sections of t h e Wooster
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 CHEMISTRY
560
farm located on silt loam soil which is derived from sandstones and shales. Ames and Schollenbergerl had made determinations of the lime requirement upon these soils by the Veitch, Hopkins, Hutchinson-MacLennan, MacIntire, and vacuum methods and all were tested with litmus paper and found t o give a decided i‘eaction. “The west half of the plots had been treated with 1,875 lbs. per acre of calcium oxide in 1903, and 2 , 0 0 0 Ibs. of limestone in 1909. The composition of t h e lime materials applied was such t h a t t h e equivalent of 5,700 lbs. of calcium carbonate had been applied t o t h e lcmed halves of the plots previous t o t h e time samples were taken from t h e plots, which was three years after the last treatment with lime.”2 The amount of lime left was negligible. All samples gave a decided acid reaction t o litmus and when mixtures of t h e soils with recently boiled distilled water were tested with the hydrogen electrode all shdwed a hydrogen-ion concentration greater t h a n IO-?. Hydrogen-ion concentrations were determined upon these soils by use of the hydrogen electrode, using 0 . 5 N potassium chloride solution containing various predetermined amounts of lime. The samples were shaken for 3 hrs. preceding t h e readings given i n Table
I.* TABLE I-HYDROGEN-IONCONCENTRATIONS O F SOLUTIONS CONTAINING OF LIME HADBEEN ADDED OHIO SOILS TO WHICH FIXEDAMOUNTS (Readings are given in volts) OT. 1.T. 2 T . 3T. 4.T.. PLOT FERTILIZER Lime Lime Lime Lime Lime 0 None 0.5174 0.5684 0.6300 0.6739 0.7450 None. Lime . . . . . . . . . . . . . . 0.5670 0.6406 0.6850 0.7393 2 Acid Phosphate.. 0.5209 0.5725 0.6392 0.7000 Acid Phosphate Lime.. . . 0.5760 0.6561 0.6974 0.7473 .... 5 Sodium Nitrate.. 0.5184 0.5671 0.6317 0.6862 0.7482 Sodium Nitrate Lime. . . . 0.5803 0.651 1 0.7103 0.7540 11 Acid Phosphate Mineral Potash Sodium Nitrate 0.5164 0.5657 0.6308 0.6920 Acid Phosphate Mineral Potash Sodium Nitrate +Lime 015626 0.6398 0.6865 0.7421 24 Acid Phosphate Mineral Potash Ammonium Sulfate Lime.. 0.5445 0.6230 0.6612 0.7260 Mineral Potash 26 Bone Meal Sodium Nitrate.. 0.5209 0.5731 0.6375 0.6774 0.7394 Bone Meal Mineral Potash SodiumNitrate Lime 0.5516 0.6265 0.6841 0.7312 Mineral Potash 29 Basic Slag Sodium Nitrate.. ...... 0.5220 0.5794 0.6271 0.6826 0.7339 Mineral Potash Basic Slag Sodium Nitrate Lime 0.5668 0,6424 0.7074 0.7467 . . . . 18 Manure. .................. 0.5202 0.5659 0.6164 0 6622 0.6938 Manure Lime.. 0.5574 0.6163 0.6708 0.7218 . . . .
..................... +.......... +..........
+ + + +
+ + + +................. + + + ........... + ...... + + + + + + .........
.... ....
.... .... ....
....
....
By interpolating t h e above results as straight line functions t o determine the amount of lime necessary t o lower the hydrogen-ion concentration t o 10-7, using 0.69 volt as the potential a t this concentration, a comparison may be made directly with the results given by Ames and S~hollenberger.~This comparison has been made in Table 11. The results are given in pounds of lime as C a C 0 3 required per acre. The following conclusions may be drawn from a study of Table 11: I-The vacuum method approaches nearer t o t h e lime requirement as shown by the hydrogen electrode t h a n do any of t h e other methods, but with this method the results are uniformly higher. It may be assumed 1 2
8 4
THISJOURNAL, 8 (1916), 243. I b i d . , 8 (1916). 224. For method and apparatus see P a r t 11, Ibid., 12 (1920), 457. I b i d . , 8 (1916), 244.
Vol.
12,
No. 6
t h a t if the soils had been shaken with the lime for a longer peridd t h a n 3 hrs. the lime requirement as shown by t h e hydrogen electrode would have approached t h a t given by the vacuum method. 2-It is quite evident t h a t the above methods, with t h e possible exception of the vacuum method, do n o t indicate the amount of lime necessary t o completely neutralize a soil, especially in t h e presence of neutral salts, except for a very limited period. TABLE 11-COMPARISONOF THE AMOUNTS OF LIME REQUIREDB Y OHIO SOILSAS SHOWN BY VARIOUSMETHODS
PLOT FBRTILIZER 1 None .......................... 3440 2000 3550 2925 7300 6456 None. Lime . . . . . . . . . . . . . . . . . . . 100 Alk. 2250 1700 4900 4225 2 Acid Phosphate.. . . . . . . . . . . . . . . . 2640 2000 3850 2700 7800 5670 Acid Phosphate Lime.. . . . . . . . 80 Alk. 2400 975 3800 3640 5 Sodium Nitrate.. 3640 1200 3550 2550 6200 6122 Sodium Nitrate Lime.. . . . . . . . 120 Alk. 2500 1250 4225 3310 11 Acid Phosphate Mineral Potash Sodium Kitrate.. . . . . . . . . . . . 3080 1800 3850 2825 7100 5960 Acid Phosphate Mineral Potash Sodium Nitrate Lime.. 80 Alk. 2500 1375 5900 4126 24 Acid Phosphate Mineral Potash AmmoniumSulfate Lime.. 4240 3000 4000 2700 8300 4889 26 Bone Meal Mineral Potash f Sodium Nitrate 2940 2000 3700 2250 7350 6407 Bone Meal Mineral Potash Sodium Nitrate Lime.. ..... 360 Alk. 2900 1325 4050 4250 29 Basic Slag Mineral Potash Sodium Nitrate.. . . . . . . . . . . . . . 2560 1200 3600 2250 6600 6288 Basic Slag Mineral Potash Sodium Nitrate Lime.. 150 Alk. 2100 1075 4050 3460 18 Manure. ....................... 2760 2600 4200 3100 8500 7760 Manure Lime 120 Alk. 2950 1950 5200 4937 1 Ohio Experiment Station, Bulletin SO6 (1916), 350. Hopkins’ values are given as one-half that given in the table here, for which no explanation is offered.
+ +. . . . . . . . . . . . . . . + + + .... + + + .............. + + +
+ + +
+ +
+
+
+ + .....
................
P A R T IV
T h e hydrogen electrode is not t o be recommended for determination of t h e lime requirement of soils except as i t may be valuable for checking other methods for t h e following reasons: I-It is difficult t o manipulate even by one who has had considerable experience in using it. 2-The process is slower t h a n any method so far proposed. 3-Expensive and delicate apparatus is required if satisfactory results are t o be obtained. Although i t may be found valuable for standardizing other methods, and approximate lime requirement values may be obtained by making two determinations and calculating t h e lime requirement as a linear function, the method cannot be taken seriously as a commercial laboratory method. As the time element is an important factor automatic titration would not be entirely satisfactory. O n account of t h e difficulties enumerated above, further investigations were made in t h e hope t h a t a praFtica1, rapid method for t h e determination of the lime requirement of a soil could be worked out. Tacke’s methodl would appear t o have a logical foundation but in the light of t h e present investigations i t is difficult t o conceive how i t could be expected t o yield concordant results, and i t is doubtful if it or any of t h e proposed modifications would approach t h e actual amount of lime needed to bring the soil t o t r u e neutrality. An attempt was made t o determine the lime require1
Chem.-Ztg., 20 (1897), 174
June, 1920
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
ment by mixing a weighed quantity of soil with precipitated calcium carbonate, adding recently boiled distilled water, boiling for a fixed period, a n d determining t h e evolved carbon dioxide by t h e Parr method’ as modified by Pettit.2 Concordant results could not be obtained, b u t by adding a neutral salt rather close results were obtained. T h e method used for t h e results given in Tables I and I1 below was t o take a weighed sample of soil, usually 5 or I O g., add a n excess of precipitated calcium carbonate in a 125 cc. Erlenmeyer flask, attach t o t h e P a r r apparatus, run in about 2 5 cc. of normal salt solution13 and boil for a definite periode4 The flask and condenser were filled with distilled water t o a mark upon the capillary tube connecting the condenser with the eudiometer. Readings were taken as instructed by P e t t i k 6 It is recommended t h a t I O min. be fixed as the time for boiling.
561
case of peat soils where I,OOO,OOO Ibs. were used as a basis. Other soils investigated are given in Table 11. Hopkins and hydrogen electrode determinations were made and the proposed modified Tacke determinations were made after boiling for 5, IO, and 30 min. TABLE 11-LIME
REQUIREMENTS OF SOILS A S SHOWN BY THE HOPKINS, THE HYDROGEN ELECTRODE, AND THE PROPOSED MODIFIED
TACKE METHODS~
Proposed Modified Tacke Method 7 -
Hydrogen HoDkins Electrode
SOILS
5 Min.
IO Mln.
30 Min.
Black ... ... Black 345i8 ... Peat. 1ioi 1 20772 ... Black 31342 ... Yelloy Gray 4 268b3 36640 33624 Gray Plastic Clay.. ........... 5200 11094 ... Yellow Plastic Clayey Silt. ..... 9340 i 8 i j 3 19611 Yelloa ISiltLoam 5780 14 13453 14954 17256 BrowniSandy Loam ........... 3300 4 5792 ... 1 For descriptions of soils see Part I, THISJOURNAL, 12, (1920), 340 2 More than 40000. TABLE I--COMPARISONOF LIME REQUIREMENTS OF OHIO SOILS AS SHOWN 8 More than 20000. BY VARIOUS METHODS, I N C L U D I N G THE P R O P O S E D MODIFIEDTACKE METIIOD, AND THE DIFFERENCESSHOWN B Y LIMEDA N D UNLIMED It will be noted t h a t the proposed modification of PLOTS. PREVIOUS APPLICATIONOF LIME ON LIMEDPLOTS Tacke’s method gives varying results which depend 5700 LSS. PER ACRE
PLOT FERTILIZER 0 None.... 3440 2000 3550 None Lime., 100 Alk. 2250 Difference 3340 1300 2 Acid Phosphate.. 2640 2000 3850 Acid Phosphate 4- Lime 80 Alk. 2400 Difference 2560 . . 1450 5 Sodium Nitrate.. ....... 3640 1200 3550 Lime. 120 Alk. 2500 Sodium Nitrate Difference 3520 1050 11 Acid Phosphate MineralPotasb Sodium Nitrate .............. 3080 1800 3850 Acid Phosphate f Mineral Potash Sodium Nitrate Lime 80 Alk. 2500 Difference 3000 1350 24 Acid Phosphate Mineral Potash Sodium Nitrate Ammonium Sulfate Lime ....... 4240 3000 4000 26 Bone Meal Mineral Sodium NiPotash trate. ................ 2940 2000 3700 Bone Meal Mineral Potash Sodium Nitrate Lime ......... , 360 Alk. 2900 2580 Difference. 800 29 Basic Slag Mineral Potash Sodium Nitrate ................. 2560 1200 3600 Basic Slag Mineral Potash Sodium Nitrate Lime 150 Alk. 2100 Difference 2410 1500 18 Manure. 2760 2600 4200 Manure Lime 120 Alk. 2950 Difference. 2640 1250
+ .............. ........ ............
..
+ ............
..
....... ............
++ +. . .+. . ........ ...... + + ++ ++ + + + ........... ++ + + +............ ......... ............... + ........... ........
..
..
..
..
2925 1700 1225 2700 975 1725 2550 1250 1300
7300 4900 2400 7800 3800 4000 6200 4225 1975
6456 4225 2231 5670 3640 2030 6122 3310 2812
6941 7783 6908 875 6737 7809 5123 6599 1644 1210 7264 7924 5431 2493
.. ..
.. ..
2825 7100 5960 7042 7493 1375 5900 4126 1450 1200 1834
.. ..
6184 1309
2700 8300 4889
..
6547
2250 7350 6407 6973 7530 1325 4050 4250 925 3300 2157 2250 6600 6288 1075 1175 3100 1950 1150
4060 2540 8500 5200 3300
.. .i
.. .. ..
69.51 579 7822
3460 6233 2828 1589 7760 8327 8776 4937 . . 7206 2823 1570
..
The soils given in Table I are the ones described by Ames a n d Schollenbergere and received by the writer from them. The results are calculated in pounds of calcium carbonate t o z,ooo,ooo Ibs. of soil, except in 1 J . A m . Chem. SOC.,86 (1904). 294. . 2 I b i d . , 1640. 8 Preliminary experiments showed t h a t it made little difference what neutral salt was used. Experiments were made with definite quantities of KCl, NaCl and KNOs; also by varying the amount of calcium carbonate and KC1 with duplicate results, provided there was an excess of calcium carbonate and not enough neutral salt t o change materially the boiling point of the solution. 4 If the boiling was attended with frothing a few drops of a neutral oil were added. 6 LOG. cit. 6 THIS JOURNAL, 8 (1916), 243.
.
...
..............
upon t h e time of boiling, and in every case except for peat and yellow silt loam, Table 11, the j-min. boiling period showed a higher lime requirement t h a n t h e hydrogen electrode. A Io-min. boiling period showed a higher lime requirement in every case except one (Ohio Plot No. 24, lime, Table I) t h a n did t h e vacuum method proposed by Ames and Schollenberger.1 T h a t t h e reaction is not complete even a t the end of t h e Io-min. period is shown by the increase a t t h e end of a 30-min. boiling period. The proposed method has the advantage over most of t h e others in t h a t i t gives a figure which represents t h e “power of a soil t o decompose calcium carbonate” (which may be assumed t o be a measure of the eventual lime absorption), is rapid, and approximates t h e results obtained with the hydrogen electrode. It is quite apparent t h a t the interaction a t room temperature between a soil and a caustic lime solution containing a neutral salt is not complete within 3 hrs. (which is the period a t which hydrogen-ion concentrations were determined with the hydrogen electrode), as shown by both the vacuum and the modified Tacke methods. The period required for t h e completion of the interaction a t room temperature between a soil and calcium carbonate may be assumed to be considerable for MacIntire2 has shown t h a t calcium passes slowly into the form of silicates. It is quite evident t h a t any of the proposed methods gives comparative results only. The t r u e lime hunger as i t relates t o cropping is after all the matter t h a t w e are most interested in determining, and this, i t seems, with t h e present state of our knowledge must be determined by field experiments. M E A S U R E M E N T O F T H E REDUCTION
O F ACIDITY
By subtracting the acidity values found in acid soils from those found in unlimed soils from the corresponding half plots a t the Ohio Station (Table I) differences are obtained which measure t h e residual reduction in 1
LOC.cit., P a r t 111.
2
Tennessee Experiment Station, Builetin 107 (1914).
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
562
acidity due t o previous applications equivalent t o 5 , 7 0 0 lbs. of calcium carbonate. As an average of t h e results from seven plots which afford d a t a for this measurement t h e reduction in acidity is 2,864 lbs. by t h e Hopkins method, 2,674 b y t h e vacuum method, and 2,388 by t h e hydrogen electrode, while t h e MacIntire, Hutchinson and modified Tacke methods show reductions of 1,243, 1,279, and 1,375 lbs., respectively. T h a t any method will show a greater reduction i n acidity t h a n actually occurs and remains a t t h e time of sampling seems extremely doubtful. As suggested above, t h e vacuum method appears t o furnish t h e most trustworthy measure of t h e total lime requirement and i t also seems safe t o assume t h a t t h e hydrogen electrode will give results in substantial agreement with t h e vacuum method if sufficient time is allowed. If these methods are accepted as standards, then t h e Hopkins method seems t o give correct results when used t o measure t h e reduction in soil acidity b y applications of lime. It may also measure with accuracy the most immediate lime need, although i t does not measure t h e total power of a soil t o decompose carbonates. If we assume t h a t t h e reduction in acidity should be approximately t h e same for all limed plots, t h e Hopkins method and the hydrogen electrode show t h e highest percentage consistency. CONCLUSIONS
I-A
method has been proposed for determining t h e power of a soil t o decompose calcium carbonate which approximates t h e results obtained b y use of t h e hydrogen electrode. 2-The Hopkins and t h e hydrogen electrode methods show t h e highest percentage consistency for measuring t h e reduction of acidity for limed soils. THE DETERMINATION OF ZIRCONIUM IN STEEL' By G . E. F. Lundell and H. B. Knowles BUREAUO F STANDARDS, WASHINGTON, D.c. Received November 3, 1919
1-1
NTR 0 D U C T I 0 N
Any generally applicable method for t h e determination of zirconium i n steels must make provision for a variety of elements which may be present as intentional or as accidental alloying constituents. Among such elements are titanium, aluminum, chromium, tungsten, vanadium, phosphorus, and, less commonly, uranium and cerium. Since zirconium steels very often contain aluminum and titanium, i t is most desirable t h a t any proposed method for t h e determination of zirconium should also provide for t h e determination of these analytically related elements in t h e same portion of steel. I t is t h e purpose of this paper t o give a critical review of the methods which have been published for this determination, t o present methods which have been considered, and t o describe a method which has been worked out a t the Bureau of Standards. This method is not considered final and ideal, b u t i t is t h e result of an effort t o meet t h e requirements listed above. '
1
Published by permission of the Director of the Bureau of Standards.
Vol.
12,
No. 6
11-HISTORICAL
have described a method for t h e analysis of alloys of nickel and zirconium, which makes provision for silicon, tungsten, nickel, aluminum, zirconium, manganese, and small percentages of iron. Elements such as titanium and chromium were n o t encountered by t h e authors named, and therefore no provision was made for their separation and determination. Their method cannot be applied directly t o t h e analysis of material high in iron, like zirconium steels. P E R G C S O N METHODs-Ferguson2 has given three optional methods for t h e determination of zirconium in steel. Abstracts of these methods are given with comments below. K E L L E Y A N D AIEYERS'
Method I-The steel is dissolved in hydrochloric and nitric acids, the solution treated with sulfuric acid, evaporated to dryness, and the residue cooled and taken up in dilute sulfuric acid. The silica is filtered off, ignited, treated with sulfuric acid in excess, then with hydrofluoric acid; the solution is evaporated to the appearance of fumes, diluted and filtered. The filtrate is added to the previously obtained filtrate and the whole is nearly neutralized with ammonium hydroxide, treated with ammonium bisulfite and heated to boiling until the iron is reduced. The solution is cooled, made slightly alkaline with ammonium hydroxide, then slightly acid with hydrochloric acid, boiled, and precipitated with phenylhydrazine. After digestion, the precipitate is filtered off, dissolved in hydrochloric acid, reprecipitated with phenylhydrazine after ammonium bisulfite reduction, filtered, washed, ignited, and weighed. The ignited oxides are fused with sodium carbonate, the melt is treated with water, and aluminum separated by treatment with sodium hydroxide followed by filtration. The insoluble residue is ignited and fused with potassium pyrosulfate; the melt is dissolved in water, and the,zirconium precipitated with ammonium hydroxide if iron is absent, or with phenylhydrazine after reduction when iron is present; the precipitate is filtered and ignited to zirconium oxide.
This method, if we grant quantitative separations, is still open t o t h e following objections: I-No provision is made for titanium, which is a common constituent of zirconium steels and which will accompany t h e latter through all t h e separations a n d finally be counted as zirconium oxide. 2-No provision is made for chromium, which is a possible contaminant of zirconium steels and which will be counted as aluminum in this method if t h e carbonate fusion takes place in a n oxidizing atmosphere, a n d as zirconium if t h e atmosphere is reducing. 3-Phosphorus in t h e steel will be present as phosphorus pentoxide in t h e phenylhydrazine precipitate and will be reckoned finally as aluminum. 4-Cerium, uranium, and vanadium will also cause complications, t h e cerium being counted as zirconium, while vanadium and uranium will go with t h e aluminum. Method 11-In this method Ferguson proceeds as in Method I until the reduced iron solution has been rendered slightly alkaline. A t this point the solution is treated with z cc. of concentrated sulfuric acid, diluted to 400 cc., and disodium phosphate added. After boiling and digestion, the precipitate is filtered off, washed with one per cent sulfuric acid, then with hot water, ignited, blasted, and weighed as zirconium phosphate, for which the zirconium factor 0.3828 is given 1 2
THISJOURNAL, 9 (1917), 854. Eng. Mzning, 106 (1918), 793.
