Nov., 1914
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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
itself would be desirable for certain purposes. For I O g. dry pulp, 0.054 g . of t h e material, followed b y a n equal weight of aluminum sulfate, gave a well sized paper, a n d 0.013j g . a very light size. T h e crude liquor, which contains this precipitate already dissolved in S a O H together with inorganic salts, can also be used as a size for colored papers. 11-STAIS A N D VARNISH F O R wooD-The precipitate dissolved in dilute alkalies or alcohol can be applied t o wood for a brown stain. It cannot be used as a varnish, for t h e residue contracts on drying. If, howeTTer, t h e total crude precipitate is treated with chloroform, a b o u t half t h e precipitate b y weight dissolves; this solution on drying leaves a surface which does not contract, a n d which resembles varnish. I t can be applied in chloroform, methyl or ethyl alcohol. or other volatile solvent. T h e part insoluble in chloroform can be used for a stain. There is some prospect t h a t b y precipitating t h e original precipitate fractionally, a fraction which can be used for a varnish might be obtained without using chloroform, b u t this has not been accomplished with entire success as yet. 111-SULFURDYE-If the dry precipitate is mixed with powdered potassium sulfide (sodium sulfide has not been tried) a n d sulfur, a n d heated t o I8j' t o 2 3 0 ° C.,a n odorous gas is given OK, a n d t h e residue when extracted with water gives a solution which dyes wool, silk, a n d cotton a d a r k brown or black. T h e dye is t a k e n b y cotton without a mordant, a n d is quite fast t o sunlight. Heating t h e mass t o 310' destroys t h e dye which is first formed. IV-If t h e precipitate is treated with nitric acid a solution is obtained which dyes wool brown if t h e acid is weak, or yellow if stronger acid is ttsed. These dyes appear t o be fast. They may also be obtained b y nitrating t h e crude liquor. If t h e filtrate f r o m t h e precipitate thrown down with HC1 is distilled, t h e distillate obtained contains acetic acid a n d some other compound, probably a phenol. T e n cc. of t h e distillate obtained from I jo cc. crude liquor with 4j cc. conc. HCl, when titrated with N a O H with phenolphthalein as indicator, required 40.3 cc. N / I O N a O H . T h e distillate with silver nitrate gave no precipitate of silver chloride, b u t on standing a red crystalline precipitate appeared. With a cold water solution of potassium nitrite t h e distillate gave a crystalline precipitate, t h e filtrate from which dyed n.001 a n d silk brown, b u t did not dye cotton. Crystalline precipitates were also obtained with nitric acid (this precipitate was dissolved if stronger nitric acid was added), ferric chloride, bromine water, a n d potassium permanganate. When treated with chlorine gas or a solution of bleaching powder the distillate gave a red solution which dyed wool a n d silk brown. T h e coloring matter could be removed f r o m t h e water solution by extracting with chloroform. T h e residue f r o m t h e distillation could not be evaporated t o dryness on the s t e a m bath, which shows t h a t some organic substance is present. T h e principal compound present, however, is sodium chloride,
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from which t h e organic matter may be burned off. This residue left on evaporation if heated somewhat under certain conditions is partly changed t o a substance soluble in dilute alcohol b u t not in water. The alcoholic solution on being evaporated leaves a varnish-like coating. If the filtrate from the hydrochloric acid precipitate of the crude liquor, before being distilled, is extracted with chloroform a n d the chloroform evaporated, a red colored residue is left. This is somewhat soluble in hot water t o a colloidal solution which dyes silk pink, but does not dye cotton or wool. The color on silk, however, fades very rapidly. If this water solution is treated with bromine or chlorine, a solution is obtained which dyes wool brown a n d silk gray; these colors are much faster t h a n the pink. Ammonium persulfate gives browns on silk a n d wool, b u t not on cotton. Potassium nitrite gives a brown for silk. T h e reason for publishing this investigation in the above fragmentary form, is the hope t h a t attention m a y be called by it t o the possibilities of a present waste product a n d t h a t investigation may be directed thereto, a t this particularly opportune time. BOWDOINCOLLEGE,BRUNSWICK, MAINE
SOME RAPID METHODS FOR GLASS ANALYSIS By E. C. SULLIVAN A N D W. C. TAYLOR Received August 15, 1914
Some convenient methods which we have developed for the routine analyses of glasses may be capable of further application a n d we therefore desire t o bring t h e m t o t h e attention of others. Our original procedure for a complete analysis was t o determine t h e alkalies b y the J . Lawrence Smith method a n d the other bases a n d silica by fusion with soda. In some cases we were able t o make use of the decomposition of glass by hydrofluoric and sulfuric acids. After some experimenting we found t h a t we could use oxalic acid in place of sulfuric t o decompose t h e fluorides. The oxalates can in t u r n be decomposed by heat so t h a t no bases or acids are introduced t o interfere with the determination of t h e glass constituents. By this method t h e complete analysis of a glass may be finished in one day. This method was developed for t h e analysis of a large number of glasses of the same type. These contained silica, lead, soda a n d potash in varying proportions with small amounts of iron, alumina, 1 T h e radiator used was made up from a description by W. F. Hillebrand in Bullclin No. 422, U. S. Geol. Survey, p. 31, and is described here a s i t has considerable
influence on the success of the method. R is of sheet iron, aluminum or nickel, 6 t o i cm. high, 8 cm. wide a t top and 5 cm. at bottom. T h e base B may be of iron, nickel or platinum b u t not of aluminum, which will not stand the temperature of the direct flame. B is attached to R b y turning the cogs of B up and over those of R. A platinum triangle should be inserted about 4 cm. from t h e base. An aluminum ring with a n opening slightly larger than the underlying crucible should be placed over the radiator to hasten evaporation.
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manganese, lime a n d magnesia as impurities. For these glasses t h e following method was used: One gram of finely powdered glass is placed in a platinum crucible of. about 4 0 cc. capacity, moistened with water, 2 g. of HzC204 crystals added a n d enough 48 per cent H F t o fill t h e crucible half full. This is evaporated to dryness on a radiator,' t h e temperature of which is just high enough t o expel t h e excess of oxalic acid. When all t h e acid has been expelled the crucible is cooled a n d t h e evaporation repeated twice more with oxalic acid a n d water. T h e amount of oxalic acid used is about j g. in all. It was necessary t o know t h e a m o u n t used as a blank showed 0 . 0 0 1 2 g. of alkali chlorides from this source. After t h e third evaporation, when all t h e excess of oxalic acid is expelled, t h e remaining oxalates are taken up with hot water, allowed t o cool a n d filtered. T h e residue which, in t h e case of t h e glasses mentioned, consists of P b C 2 0 4 only, with trace of CaC204, may be titrated directly with K M n 0 4 or dissolved in dilute " 0 3 a n d determined as sulfate. T h e filtrate f r o m the P b C 2 0 4 is evaporated t o dryness in a platinum dish a n d then heated over a free flame until oxalates are decomposed. T h e carbonates are then taken up with water a n d HC1 a n d t h e mixture is evaporated t o dryness t o remove t h e small a m o u n t of SiOz. T h e salts are taken up with a few drops of HC1 a n d hot water, a few drops of bromine water added, then a little ammonia, a n d t h e solution is boiled. T h e precipitate of hydroxides of iron, aluminum a n d manganese is filtered off, ignited a n d weighed. T h e filtrate is divided into two equal portions. T o one are added and ( N H 4 ) 2 H P 0 4 ,which precipitate a small a m o u n t of I mg. This is calculated t o chloride magnesia-about a n d deducted fiom weight of NaC1, KCI. The other half is evaporated t o dryness, ammonia salts expelled by heat a n d t h e chlorides weighed. The MgClz found a n d alkali from blank determination on all reagents are subtracted a n d t h e K20 determined by t h e platinum chloride method a n d NazO by difference. T h e following table will show some of the results obtained on weight of alkali chlorides from I g. sample: J. L. Smith Glass No. I.......
method Gram 0.1170 0.1168 0.1176
Oxalate Gram 0.1175 0.1162 0.1169 0.1163
J. L. Smith method Gram 0,1177 0,1196 4 . . . . . . . 0.1290 S....... 0.1168
GlassNo. 2....... 3.......
Oxalate Gram 0.1199 0.1198 0.1294 0.1169
On the separation of soda a n d potash t h e oxalate method averages a b o u t 0.1j per cent lower in K 2 0 a n d correspondingly higher in Na2O. T h e lead determination b y t h e oxalate method expressed in per cent P b O compares as follows: SODA FUSION 21.00 21.13
OXALATE 21.22 21.15 21.30 21.18
T h e combined weights of iron, alumina andmanganese a m o u n t t o from I t o 1 . j per cent a n d average from 0.2 t o 0.3 per cent lower b y t h e oxalate method t h a n by t h e soda fusion. T h e amounts of CaO a n d MgO are in t h e neighborhood of 0.1 per cent a n d are slightly lower by t h e oxalate method where determined though these determinations were usually omitted. We have
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used this method since on a large number of similar samples a n d have found it satisfactory for glasses of this type. I n applying this method t o other glasses t h e procedure following the three evaporations must of course be varied. The first step is t o separate the soluble a n d insoluble oxalates. From there on the procedure may vary according t o what elements are present. T h e oxalates we have worked with group themselves as follows: INSOLUBLE SOLGBLE ' Manganese 3 Lead Copper 2 Magnesium 2 Sodium Calcium Cobalt 2 Potassium Iron 4 Aluminum Arsenic Zinc Nickel 2 Chromium Antimony 5 Cadmium 1 Barium 2 1-Almost quantitative; in presence of zinc traces present with soluble oxalates. 2-Though mostly insoluble. these elements must be looked for with the soluble oxalates unless particular precautions are taken to have conditions right t o render the oxalates insoluble. Presence of other elements also affects the solubility of these oxalates. 3- manganese up t o 2 per cent gave no test for the element with the insoluble oxalates but a glass containing 6 per cent M n O showed nearly half this amount as an insoluble oxalate. 4-Does not occur with insoluble oxalates except in zinc glasses when a small amount is found with the zinc. 5-Normally soluble but has been found with insoluble oxalates when these were heated too strongly.
Arsenic or antimony, if present, should be removed f r o m t h e soluble oxalates with H2S before t h e oxalates are decomposed. This necessitates acidifying with HCl, which must be expelled before decomposing t h e remaining oxalates; otherwise alkali chlorides are volatilized. T h e insoluble oxalates are in general dissolved in dilute HCl a n d separations made as in a n y mixture of chlorides. Borates do not interfere with t h e analysis. A number of analyses of glasses a n d silicates of other types are given t o show results obtained by this method. T h e figures given are the difference between t h e oxalate method from the soda fusion a n d J. Lawrence Smith method. They are expressed as when oxalate method is higher and - when lower.
+'
A B C D E F NarO. . . . . . . , -0.08 +0.26 -0.16 -0.11 4-0.18 + O . 14 K20 . . . . . , . . . -0.06 *O.OO +O.lO *O.OO -0.08 -0.04 -0.05 .. -0.05 CaO.. . . . . . . . -0.22 0.04 -0.08 +=O.OO +0:03 -Or04 AlzOa.FeeOs.. . ZnO .. .. +0.13 +0:07 -0.30 +0.04 , , A-An ordinary soda lime glass D-A soda zinc borosilicate B-A soda lime, zinc borosilicate E-A soda potash zinc glass F-A soda alumina borosilicate C-A soda potash zinc glass
.......
+
T h e presence of more t h a n 3 per cent alumina causes difficulty, owing t o its interfering with t h e expulsion of fluorine by oxalic acid. Except t h e lead glass all those containing A1203 gave a test for fluorine in the soluble oxalates, a n d t h e a m o u n t of such fluorine was greater for high A1203 content t h a n for low. Feldspar gave very low results for alkali. A sample yielding 0 . 1 2 4 6 g. of alkali chlorides b y the J. Lawrence Smith method gave o.og09 g. by t h e oxalate method. This was increased t o 0 . 1 1 0 2 g. b y reprecipitation of t h e alumina a n d t o 0 . 1 2 3 0 g. by a second reprecipitation. With several alumina glasses low results were obtained on both A1203 a n d alkali, while with other glasses either A1203 was low a n d alkali high or alkali was low a n d alumina high. F r o m t h e d a t a a t hand it seems as if both alkali a n d A1203 were a p t t o be lost a t some stages of the analysis but so far our results are not consistent, probably due t o t h e
Nov., 1914
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
variation in temperature in different analyses. I n some we get conditions favorable for a loss of alkali, in some for a loss of A1203 a n d sometimes for both. We have, with great care in heating, obtained only slightly low results where both A1203 a n d K a 2 0 were very high as in cryolite. T h e loss therefore probably can be prevented. Boric oxide tends t o alleviate t h e difficulty caused by alumina a n d i t does not in a n y way interfere with later determinations. Borosilicates with up t o j per cent A1203 give fairly good results. One showed 4.82 per cent A1203 a n d 0.1010 g. alkali chlorides b y regular methods a n d 4.93 per cent A1203a n d 0 . 1 0 2 7 g. alkali chlorides by t h e oxalate method. T h e results on glass G mentioned in the table are not very good, however. With glasses not containing Bz03 the addition of boric acid before evaporation with H F a n d H2C20.rdecreased t h e fluorine content of the soluble oxalates a n d also gave higher results for A1203 a n d alkali without showing a n y Bz03 present with t h e alkali. From t h e results so far we do not feel confidence in t h e method for such glasses as show undecomposed silico-fluorides, for while accurate determinations m a y be obtained with special precautions t h e method has no advantages under such conditions. For glasses which do not contain much A1203 the method seems well adapted, especially for t h e analysis of a series of glasses of very nearly t h e same composition. We have also found i t convenient for the rapid determination of As203 or Sb203 in glass.
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As iron a n d alumina are rarely present in large amounts in glass a n d as the time of the soda fusion with glass can be cut t o a few minutes the method seemed quite readily adaptable. The first glass tried was a soda alumina borosilicate which, f r o m analysis, showed a possible B203 content of 10.40 per cent by difference. Three determinations by Wherry’s method showed 10.72, 1 0 . j 7 , 10.67 per cent B203 or a n average of 10.64 per cent. A soda borosilicate containing a small amount of BaO a n d S b ~ 0 3showed 2 j.5 7 per cent B203 by Wherry’s method a n d 25.7j per cent by difference. Other glasses of same type showed: Per cent B203 by titration 25.10 12.71 17.57 14.90
Per cent BzOs by difference 25.12 12.15 17.51 15.01
With a zinc borosilicate very unsatisfactory results were obtained, t h e B 2 0 3 content b y titration running f r o m 4 t o g per cent when only 2 per cent mas present. Several mixtures of ZnO a n d sand with a known a m o u n t of B203 were r u n through by Wherry’s method a n d results for B203 were always high even after very long boiling. Solutions of ZnCI2 a n d borax were boiled with CaC03 for varying lengths of time a n d using slight excess a n d large excess of CaC03 a n d zinc was always found in t h e filtrate from the C a C 0 3 precipitate. CaO was substituted for CaC03 b u t with no better success. iXa2C03completely removed the zinc from solution a n d b y a double precipitation, using first N a ~ C 0 3a n d then C a C 0 3 , we obtained 0.0360, D E T E R M I N A T I O N O F B O R I C ACID 0.0361 a n d 0.036 j g. BzO3 when t h e theoretical amount I n t h e analysis of borosilicate glasses we have found was 0.0365 g. P b O was found t o cause the same t h a t for the determination of boric oxide t h e method trouble as ZnO a n d the same modification of the described b y Wherry’ is very useful: “Fuse the sample with about 3 g. of Na2C03 for 15 minutes. method gave satisfactory results. We have been Take up with 2 0 to 30 cc. of dilute HCl adding a few drops of able t o use t h e modified method on a large number of ” 0 3 to oxidize ferrous iron. Place in a 250 cc. round-bottomed glasses with satisfactory results. T h e modified method t h e n is as follows: Fuse flask, heat nearly to boiling, and add dry precipitated CaC03 in moderate excess. Connect with a return condenser and boil 0.5 g. of glass with 3 g. N a 2 C 0 3for one or two minutes vigorously for about I O minutes. Filter out the precipitate after mass is liquid. Take u p with 2 0 t o 30 cc. of hot through a small Biichner funnel, washing several times with hot water a n d when t h e melt is entirely decomposed filter water, but keeping the total volume of liquid below IOO cc. out a n y insoluble oxides. After washing, transfer Return the filtrate to the flask, add a pinch of CaC03 and again filtrate a n d washings t o a 250 cc. round-bottomed flask, heat t o boiling; then connect with a filter pump, through a splash a d d about 7 cc. concentrated HC1, heat nearly t o trap, and continue suction until the boiling has nearly ceased. Cool to the ordinary temperature, filter if the precipitate has a boiling a n d a d d dry precipitated CaC03 in moderate red color from iron, add four or five drops of phenolphthalein excess. From here on t h e method is as given b y and run in slowly N / I ONaOH solution until the liquid is strongly Wherry except t h a t we used Ba(OH), instead of NaOH. pink in color. Introduce about I g. of mannite and shake, where- It is also advisable t o use suction for filtering t h e upon the pink color will disappear: Add NaOH to end reac- C a C 0 3 precipitate. tion, then another gram of mannite and if necessary more alkali CORNINGGLASS WORKS,CORNING,NEW YORK until a permanent pink color is obtained.” T h e method was first tried b y fusing 0 . j g. sand a n d THE COMPOSITION OF MILK AS SHOWN BY ANALYSES 0 . 2 g. boric acid with 3 g. soda. T h e melted mass f O F SAMPLES OF KNOWN PURITY MADE BY THE MASSACHUSETTS STATE BOARD OF HEALTH was t a k e n u p with water a n d 7 cc. conc. HC1 added B y HERMANNC. LYTHCOB after transfer t o a 2 j o cc. flask. T h e method was then Received June 19, 1914 followed as described above except titration was hlilk, without doubt, is the most extensively adulmade with Ba(OH)2. T h e B203 content came from terated of a n y article of h u m a n food and, b y reason 2 t o I O per cent low, d u e t o retention of B203 b y the precipitate’from C a C 0 3 . By using suction in filtering of its variable composition, t h e detection of this a n d washing this precipitate practically I O O per cent adulteration is difficult a n d in some cases impossible. of t h e Bz03 introduced was recovered. For 0 . 2 j g. For these reasons most legislative bodies, in addition B203 = 12.40 B a ( O H ) 2 we used r s . 3 j and 12.40 cc. t o prohibiting t h e sale of adulterated milk, prohibit t h e sale of milk, the composition of which falls below 1 J . A m Chcm. SOC.,SO (1908), 1687.
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