the determination of phenol in the presence of hexamethylenetetramine and formaldehyde

hIar. , 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 E N G I N E E R I N G C H E M I S T R Y 2 0 j

NO. Fe taken . 1 . . . . . . . . . . . . . . . . . . 0.086

2 . . . . . . . . . . . . . . . . . . . 0.043 3 . . . . . . . . . . . . . . . . . . . 0.043 4 . . . . . . . . . . . . . . . . . . . 0.043 5 . . . . . . . . . . . . . . . . . . 0.043 6 . . . . . . . . . . . . . . . . . . . 0,200 i . . . . . . . . . . . . . . . . . . . 0 ,100 8 . . . . . . . . . . . . . . . . . . . . 0,100

T i taken

0,0207 0,0050 0,0030 0.0040 0.0060 0,0249 0.0186 0.0249

Ti found

0.0206 0.0049 0.0024 0.0039 0.0059 0.0253 0.0186 0.0248

Error -0.0001 -0.0001 -0,0006 -0.0001 -0.0001 +o ,0004 ~ 0 . 0 0 0 0

-0.0001

The choice of methods for the reduction of the iron is largely a matter of personal preference, since both give equally good results as seen in the tables of test analyses given above. However: i t may be said tha t the reduction of the iron in our ammoniacal solution is somewhat quicker t han t h a t by sulfur dioxide in a hydrochloric acid solution.

I n applying this method to t h e determination of t i tanium in some ores, which were previously found t o be completely decomposed by acid t reatment , t h e procedure was as follows: T o 0. ; gram of very finely pulverized sample, 2 j cc. of concentrated hydrochloric acid were added and the solution was heated upon the steam bath until no further action was observed. About 20 cc. of I : z sulfuric acid were added and the solution was cautiously evaporated to sulfuric acid fumes and then heated for an hour at a temperature just below the boiling point. After cooling, 30 cc. of water were added and the solution was warmed until the soluble salts had dissolved. The insoluble mat ter was filtered, washed three times with very dilute sulfuric acid, and finally with water at room tempera- ture. The insoluble mat ter was tested and was found t o be free from ti tanium. The filtrate was diluted t o exactly 500 cc., mixed thoroughly, and aliquot par ts were taken so t h a t the ignited precipitate would not weigh over go mg., as i t was not practical t o at- tempt t h e filtration of larger amounts of this gelatinous precipitate. To each aliquot par t z grams of tartaric acid were added and t h e method from this point was identical with t h a t described above. Three t i tanic iron ores were analyzed with the following results.

Ore A . . . . . . . . . . . . . . . . . 4 . . . . . . . . . . . . . . . . . A . . . . . . . . . . . . . . . . . B . . . . . . . . . . . . . . . . R . . . . . . . . . . . . . . . . . . . B . . . . . . . . . . . . . . . . . c . . . . . . . . . . . . . . . . c . . . . . . . . . . . . . . . . . c...... . . . . . . . . . .

Ti found T i by the volumetric method’ 13.00 7o 13.1870 13.17 . . . 13.20 , . .

24.19 . . . 23.99 24.22 2 4 . 2 2 . . . 15.82 . . . 15.86 15.94 16,OI . . .

I t is recommended t h a t for t h e general application of this method t o the determination of t i tanium in the presence of relatively large amounts of iron, the t i tanium be precipitated from a solution of about IOO cc. volume which contains ~j CC. of I : I hydro- chloric acid. Furthermore, it is recommended t h a t enough substance be taken so t h a t a t least I O mg. of t i tanium shall be present in the solution.

It was found t h a t t i tanium could be separated from aluminium and determined in the same manner as when iron is present, bu t t h a t i t was necessary t o use

1 A modification of the method in Gooch’s “Methods in Chemical Analysis,” page 242.

more hydrochloric acid in order t o prevent the pre- cipitation of aluminium phosphate. The method em- ployed was t o add 1-2 grams of tartaric acid t o t h e solut’on of t i tanium and aluminium sulfates and enough ammonia to make i t slightly alkaline. (The tartaric acid was used t o prevent the formation of the hydroxide.) Then a measured quantity of hydro- chloric acid was added and the analysis was completed in the same way as when iron was present. X volume of about IOO cc. was used in the following experiments:

N O . A10 taken 1 . . . . . . . . . . . . . . . 0.063 2 . . . . . . . . . . . . . . . 0,060 3 . . . . . . . . . . . . . . . 0 .070 4 . . . . . . . . . . 0.063 5 . . . . . . . . . . . . . . . 0 .110 6 . . . . . . . . . . . . . 0.100 7 . . . . . . . . . . . . . . . 0,120 8 . . . . . . . . . . . . . . 0.060 9 . . . . . . . . . . . . 0 . 0 6 0

10.. . . . . . . . . . . . 0.050 11 . . . . . . . . . . . . . . . 0,070 12 . . . . . . . . . 0.060 13 . . . . . . . . . . . . . . 0,050 1 4 . . . . . . . . . . . . . 0 ,100 15 . . . . . . . . . . . . . 0.150 16 . . . . . . . . . . . . . . 0.100 1 7 . . . . . . . . . . . . . . . 0 , 0 7 0

Ti taken 0.0273 0.0310 0.0248 0.0248 0.0210 0.0260 0.0310 0,0223 0.0186 0.0186 0.0248 0.0122 0.0248 0.0310 0.0186 0.0248 0.0310

T i found 0.0277 0,0308 0.0245 0.0249 0.0214 0.0263 0.0309 0.0224 0.0189 0.0182 0.0245 0,0119 0.0292 0.0473 0.0233 0.0288 0.0351

Cc. conc. Error HC1 used

$0.0004 10 -0.0002 12 -0,0003 10 +0.0001 9 +0.0004 10 f0 .0003 11 -0.0001 1 4 +O.OOOl 15 +0.0003 8 -0,0004 1.5 -0.0003 10’ -0,0003 7 +0.0044 5 +0.0163 5 +0.0047 7 +0.0040 5 +0.0041 7

These experiments indicate t h a t with a volume of IOO cc. containing 0.0 j-0. I j gram alumina i t is necessary t o have an excess of at least 8 cc. of concentrated hydrochloric acid in order t o get a satisfactory separa- tion of the t i tanium.

SHEFFIELD CHEMICAL LABORATORY YALE UNIVERSITY. NEW HAVEN. CONN

THE DETERMINATION OF PHENOL IN THE PRES- ENCE O F HEXAMETHYLENETETRAMINE AND

FORMALDEHYDE By I,. V. REDMAN, A. J. WEITH A K D F. P. BROCK

Received December 2, 1913

During a research into the rate of condensation be- tween phenols and active methylene groups in the pro- duction of synthetic resins i t became necessary for us t o find a rapid and accurate method for the determina- tion of phenols in the presence of substances containing methylene groups, e . g., formaldehyde, hexamethylene- tetramine, etc.

I n previous papers’ we have described a bromination method which serves for the very accurate and rapid quantitative determination of phenol in a water solu- tion. The method consisted in diluting the phenol t o N / ~ o o o , in acid solution, shaking t h e solution for I minute after the bromide-bromate solution is added, then adding KI, shaking again for I minute and titrating the excess iodine with thiosulfate. The whole opera- tion was carried out a t zc-zj’ C.

The present paper deals with the determination of phenol in a water solution in the presence of hexa- methylenetetramine or formaldehyde or both, using the above method with whatever modifications are mentioned later in this paper.

1 Redman and Rhodes, THIS JOURNAL, 4 (1912), 655; Redman, LYeith and Brock, I b i d , 6 (1913). 389.

206 T H E J O U R N A L O F I N D U S T R I A L

The first of these probable interfering substances to be tried was hexamethylenetetramine and the results are given in the accompanying table. Hexamethylene- tetramine does not interfere in the determination of phenol by bromine when present up to I per cent of t h e total solution,' i. e . , 30 mols. of hexamethylenetetra- mine t o I mol. of phenol. Muchlarger amounts than this have been tried. AS much hexamethylenetetra- mine as I j per cent of t h e total solution, i. e . , 4 j o mols. of hexamethylenetetramine to I mol. of phenol, has been added in a single determination of the phenol without changing t h e results. The only intermediate change noted when the hexamethylenetetramine was present in large quantities was a tendency on the par t of t h e free iodine to form a brick-red granular precipitate, or a beautiful iridescent crystalline precipitate with the excess hexamethylenetetramine. This precipitate which is either the tetra-iodo-hexamethyltetramine or di-iodo- hexamethyltetramine dissolves u p readily on the ad- dition of the thiosulfate giving back t h e free iodine, and does not in any way interfere in the quantitative determination.

The presence of free formaldehyde, however, inter- feres very seriously with the phenol determination. Results t h a t are 7-8 per cent too high are obtained when the total solution is one per cent formaldehyde as is shown in the table (Expts. j and 6). The higher the percentage of formaldehyde present the higher the results which are obtained for the phenol present in the solution until, for 40 per cent formaldehyde, bromine is absorbed in very large quantities and no precipitation of tribromphenol takes place, and the determination of phenol by this method is quite impossible.

I t is evident then t h a t if hexamethylenetetramine does not interfere with the determination, and formal- dehyde does interfere, t h e addition of ammonia to t h e solution in which formaldehyde is present as a n interfering substance may , by forming hexa- met hylenetetramine with the aldehyde obviate the trouble.

The addition of ammonia t o a phenol solution con- taining formaldehyde was tried and the results are given in t h e table, Expts. 7 , 8, 9, IO. If the unknown phenol solution be made 2 N with ammonia and the whole allowed to s tand for 5 minutes, the formalde- hyde is transformed over into hexamethylenetetra- mine or some intermediate non-interfering compound a n d the determination of t h e phenol may be made with speed and accuracy. Allowing the ammonia, formaldehyde and phenol t o remain together in the water solution longer t h a n j min., e. g., 18 hours, before the determination is made does not affect t h e results as is shown in Expts. 9 and IO.

This method of determining phenol in the presence of formaldehyde would not hold if a condensing agent had been present previously or if the solution had been t reated in a way which tended t o form oxybenzyl- alcohol, saligeno-saligenin, etc.

I n determining phenol in the presence of hexa- methylenetetramine the bleaching of the starch iodide

1 The total solution refers t o the volume after the dilution has been made with the water and acid, before adding the bromine solution.

A N D E N G I N E E R I N G C H E M I S T R Y Vol. 6, No. 3

1 . . . . . . 0 . . . . . 6 16.92 3 .42 100 2 . . . . . . 0 . . . . . 6 17.10 3.59 100 3 1 gram hexa. 0 . . . . . 6 16.97 3.56 99.36

5 3 cc. 40% CHzO 0 . . . . . 6 17 .00 2.52 106.92 4 1 gram hexa. . O . . , . . 6 18.68 5.17 100.19

6 3 CC. 407, CHzO 0 , . , , . 6 18.46 3 . 7 0 108.32 7 3 c c . 40% CHzO 10 5 min. 17 16.40 2.92 99.72 8 3 cc. 407, CH20 10 5 min. 17 15.89 2.40 99.50 9 3 cc. 40% CHzO 10 18 hrs. 17 16.98 3 .54 99.50

10 3 cc. 40y0 CHzO 10 18 hrs. 17 16.62 3.16 99.51

Hydrochloric acid = 37y0 solution. N/10 ammonia = 28% solution.

Water of dilution = 100 cc. Phenol solution used = 15 cc. Bromide-bromate sol. = 0.09970 N . Thiosulfate = 0.09825 N .

color by the thiosulfate is slightly retarded by the presence of hexamethylenetetramine and i t is necessary to give a few seconds after the addition of the thio- sulfate t o allow the blue color time to disappear.

C O N C L U S I O N S

I. Phenol in the presence of hexamethylene- tetramine may be determined by the method already described for the determination of phenol.

11. Formaldehyde interferes with the volumetric determination of phenol by bromine.

111. The addition of strong ammonia to the phenol- formaldehyde solution forms with the aldehyde, hexamethylenetetramine or some intermediate am- monia-aldehyde product which does not interfere with the quantitative determination of phenol.

DEPARTMENT OF INDUSTRIAL RESEARCH UNIVERSITY OP KANSAS, LAWRENCE

ULTIMATE ANALYSES OF COAL. TAR PITCHES By C . R. DOWNS

Received December 6, 1913

I n connection with a n investigation of coal t a r pitches, the ultimate analyses of some briquet pitches were obtained.

ANALYSES O F THREE TYPICAL COAL TAR BRIQUET PITCHES OF AMERICAN ORIGIN

Pitch No. 1 Per cent

Carbon . . . . . . . . . . . . . . . . . . . . 92.05 Hydrogen . . . . . . . . . . . . . . . . . . 4.83

Sulfur . , . . . . . . . . . . . . . . . . . . . . 0 .92 Mineral ash. . . . . . . . . . . . . . . . 0 .09 Oxygen (by difference). . . . . . . 1.16 Free carbon. . . . . . . . . . . . . . . . 33.7

Nitrogen.. . . . . . . . . . . . . . . . . . 0 .95

Melting point 112O C. , 87' C., 84O C.

Pitch No. 2 Per cent

92.37 4.96 0.61 1.00 0.78 0.28

31.3

Pitch No. 3 Per cent

93.09 5.01 0 . 8 9 0.85 0 .35 0.00

26.4

The carbon and hydrogen were determined by the regular combustion method, taking proper precautions to eliminate the sulfur and nitrogen. The sulfur was determined by combustion in a bomb with oxygen under pressure (sodium peroxide being used to insure complete oxidation), and precipitated as barium sul- fate. The Kjeldahl method was used for the nitrogen.

The melting points and free carbon contents of the pitches were also determined in the usual way.

RESEARCH DEPARTMENT LABORATORY BARRETT MANUFACTURING CO., NEW Y O R K