September, 1928
I-VDUSTRIAL A X D ENGINEERIXG CHEMISTRY
979
be relieved. The developed work was then turned over to the rated president of the Chemists’ Club. Confronted with the need newly organized publicity department of the SOCIETY. H. E. for a declaration of principles upon which the club would be conHowe was also a member of this committee and still remains in ducted in those trying war days, his presentation was in language clear and true showing the manner of his Americanism and what command of the work as now conducted. was expected from others.’ On invitation from Harper & Brothers, Ellwood Hendrick He has been an officer in many other technical societies and has wrote his Erst book on chemistry for the general public, “Everyman’s Chemistry,” in 1917. From 1918 to 1923 he served as con- many activities which keep him in touch with the thought trends AND METALLURGICAL EKGINEERING,of the times. His two outstanding present occupations are in the sulting editor of CHEM~CAL chemical engineering faculty of Columbia University as curator contributing those inimitable editorials so readily recognized by their grace of expression and charm of thought. About the same of the Chandler Museum, and also as director and member of the time that “Everyman’s Chemistry” was produced, “Opportuni- executive committee of The Research Corporation. In his student days Hendrick had such distinguished instructies in Chemistry” was written a t Harper & Brothers’ request for the use of returning soldiers. In 1918 the same publishers i% tors as Victor Meyer, Victor Merz, Wilhelm Weith, Gottfried duced the assembling in “Percolator Papers” of a series of essays Kinkel, and others, and he joined a corps and fought many duels. His later friendships brought to him men of outstanding cultioriginal in their thought, delightful in their humor and breadth of vision, beautiful in their style, exhibiting the great sympathy for vation such as Lafcadio Hearn, Arthur D. Little, J. V. N. Dorr, Charles Baskerville, Edgar F. Smith, Theodore Richards, and life of Ellwood Hendrick, who found human interest and poetry in science, art, ethics, philosophy, and education. The book is Jacques Loeb. Ellwood Hendrick is deeply interested in philosophical specudedicated “To J. P. H. for a million reasons.” The initials are those of his wife. I mention a few of the essays by title--“The Sense lation and what especially interests his curiosity is a solution of of Smell,” “C2H50H,” “Science in the Humanities,” “The Chem- the nature of olfactory phenomena. He received an honorary ists of the Future,” “At the Club,” and in the “Afterword” some D.Sc. from Franklin and Marshall College in 1921. He is keenly further gleamings of our Worthy’s literary aspirations are indi- interested in the fine arts and in music. In his leisure hours he forgathers with authors, artists, playwrights, and actors, as well cated. KOchemist has a complete chemical acquaintance without CHARLES F. ROTH knowledge of this book. These essays have become a college text. as with men of science. On May 1, 1918, Ellwood Hendrick was elected and inaugu1 J. IND. ENG. CHEM., 10, 489 (1918)
Recommended Specifications for Analytical Reagent Chemicals‘ Citric and Tartaric Acids, Alcohol 95 Per Cent and Absolute, Calcium Chloride, Anhydrous, Magnesium Chloride, Methanol, Potassium Ferricyanide, Potassium Ferrocyanide, Sodium Bisulfate Fused, Sodium Chloride, Zinc Chloride W. D. Collins, H. V. Farr, Joseph Rosin, G . C. Spencer, a n d Edward Wichers COMMITTEE
ON
ANALVTZCAL REAGENTS, AMERICAN CHEMICAL SOCIETY
T
H E specifications given below are intended to serve for reagents to be used in careful analytical work. The limits and tests are based on published work, on the experience of members of the committee in the examination of reagent chemicals on the market, and on the studies of the tests made by members of the committee as the various items were considered. Suggestions for improvement of the specifications will be welcomed by the committee. In all the directions the acids and ammonium hydroxide referred to are of full strength unless dilution is specified, dilution 3) means 1 volume of the reagent or strong indicated as (1 solution with 3 volumes of water; “water” means distilled water of a grade suitable for the test described; reagents used in making the tests are supposed to be of the grade recommended below or in previous publications2 from the committee. Directions for the preparation of the ammonium molybdate solution are given under the test for phosphate in ammonium nitratc3 A time of 5 minutes is to be allowed for the appearance of precipitates and before observation of color reactions, unless some other time is specified. Blank tests must be made on water and all reagents used in the tests unless the directions provide for elimination of errors due t o
+
1 Presented in connection with the report of the Committee on Analytical Reagents a t the 75th Meeting of the American Chemical Society, St. Louis, Mo., April 16 t o 19, 1928. IND. ENG. CHEM.,17, 756 (1925); 18, 036. 759 (1926); 19, 645, 1309 (1927). * Ibid., 19, 045 (1927).
impurities. Solutions of samples must be filtered for tests in which insoluble matter would interfere. Acid, Citric REQUIREMENTS Insoluble Matler-Not more than 0.005 per cent. Residue on Ignilion-Not more than 0.020 per cent. Oxalafe (CzOr)-To pass test (limit about 0.05 per cent). Phosphale (PO,)-Not more than 0.001 per cent. Sulfate (S0a)-Not more than 0.002 per cent. Tavlrate (CnH6Oa)-To pass test (limit about 0.2 per cent). Heavy Melals-Not more than 0.0005 per cent as lead. Iron (Fe)-Not more than 0.0005 per cent.
TESTS Insoluble Molter-Dissolve 10 grams in 50 cc. of warm water and allow to remain on the steam bath for 1 hour. Filter through asbestos in a Gooch crucible, wash thoroughly, dry at 105’ to 110’ C., and weigh. The weight of the residue should not exceed 0.0005 gram. Residue on Ignition-Gently ignite 5 grams at the lowest possible temperature. The weight of the residue should not exceed 0,0010 gram. Oxalate-Dissolve 5 grams in 25 cc. of water and add 2 cc. of 10 per cent calcium acetate solution. No turbidity or precipitate should appear after standing for 4 hours. Phosphate-Mix intimately 5 grams of the powdered sample with 1 gram of magnesium nitrate and ignite in a platinum dish. Treat the residue with 20 cc. of water and 5 cc. of nitric acid and boil for a few minutes. Cool, filter, and wash with a little water. Nearly neutralize the filtrate with ammonium hydroxide, add 25 cc. of ammonium molybdate solution, shake (at about 40’ C.) for 5 minutes, and allow t o stand half an hour. Any precipitate formed should not be greater than is produced when a quantity of an alkali phosphate containing 0.05 mg. of phosphate (Pod) is treated according to the above procedure.
I N D UXTRIAL AND ENGINEERING CHEMISTRY Sulfate-Dissolve 10 grams in 100 cc. of water, add 5 drops of hydrochloric acid, heat to boiling, add 5 cc. of 10 per cent barium chloride solution, heat for 2 hours on the steam bath, and allow to stand overnight. If a precipitate is formed, filter, wash, ignite, and weigh. The weight of the barium sulfate should not exceed 0.0005 gram. Tartrate-Carefully powder about 1 gram, taking precautions to prevent contamination during the powdering. Mix 0.5 gram of the powdered sample with 10 cc. of sulfuric acid in a test tube previously rinsed with sulfuric acid. Heat the mixture a t 110' C. (in a brine bath) for half an hour, keeping the test tube covered with a beaker during the heating. The color of the solution should be yellow but not brown. Heavy MetalsDissolve 5 grams in 15 cc. of water and 3 cc. of hydrochloric acid, add 2 cc. of sulfur dioxide solution, boil 2 minutes, and cool. Cautiously add under the hood 1 cc. of 10 per cent sodium cyanide solution and 7 cc. of ammonium hydroxide. Cool, dilute to 25 cc., and add 3 drops of 10 per cent solution of sodium sulfide. The brown color should not be greater than is produced when a quantity of lead nitrate containing 0.025 mg. of lead is treated in the same way with the quantities of reagents used in the test. Iron-Dissolve 2 grams in 20 cc. of water, add 5 drops of nitric acid and boil for about a minute. Cool, add 2 cc. of hydrochloric acid, dilute to 25 cc., and add 2 cc. of 10 per cent ammonium thiocyanate solution. Any red color should not be greater than is produced when a quantity of an iron salt containing 0.01 mg. of iron is treated in the same way.
Acid, Tartaric REQUIRRMENTS Insoluble Matter-Not more than 0.005 per cent. Residue on Ignition-Not more than 0.020 per cent. Oxalate (CzO$-To pass test (limit about 0.10 per cent). Phosphate (Pod-Not more than 0.001 per cent. Sulfate (SOil)-Not more than 0.005 per cent. Heavy Metals (as lead)-Not more than 0.0003 per cent as lead. Iron (Fe)-Not more than 0.0005 per cent.
TESTS Insoluble Matter-Dissolve 10 grams in 50 cc. of warm water and allow to stand on the steam bath for 1 hour. Filter through asbestos in a Gooch crucible, wash, dry a t 105' t o 110' C., and weigh. The weight of the residue should not exceed 0.0005 gram. Residue on Ignition-Gently ignite 5 grams a t the lowest possible temperature for complete combustion of the carbon. The weight of the residue should not exceed 0.0010 gram. OxalateDissolve 5 grams in 30 cc. of water and divide into two equal portions. Neutralize one portion with ammonium hydroxide, using litmus paper as indicator. Add the other portion and enough water to make a total volume of 40 cc. Shake well and cool t o 15' C. for about 15 minutes. Filter and t o 20 cc. of the filtrate add an equal volume of saturated solution of calcium sulfate. No turbidity or precipitate should appear in 2 hours. Phosphate-Mix intimately 5 grams of the powdered sample with 1 gram of magnesium nitrate and ignite in a platinum dish. Treat the residue with 20 cc. of water and 5 cc. of nitric acid and boil for a few minutes. Cool, filter, and wash with a little water. Nearly neutralize the filtrate with ammonium hydroxide, add 2 5 cc. of ammonium molybdate solution, shake (at about 40' C.) for 5 minutes, and allow to stand half an hour. Any precipitate formed should not be greater than is produced when a quantity of an alkali phosphate containing 0.05 mg. of phosphate (PO4) is treated according to the above procedure. Sulfate-Dissolve 8 grams in 100 cc. of water, add 5 drops of hydrochloric acid, heat to boiling, add 5 cc. of 10 per cent barium chloride solutio.> heat for 2 hours on the steam bath, and allow to stand overnight. If a precipitate is formed, filter, wash, ignite, and weigh. T h e weight of the barium sulfate should not exceed 0,0010 gram. Heavy Metals-Dissolve 5 grams in 15 cc. of water and 3 cc. of hydrochloric acid, add 2 cc. of sulfur dioxide solution, boil 2 minutes, and cool. Cautiously add under the hood 1 cc. of 10 per cent sodium cyanide solution and 7 cc. of ammonium hydroxide. Cool, dilute to 25 cc., and add 3 drops of 10 per cent solution of sodium sulfide. The brown color should not be greater than is produced when a quantity of lead nitrate containing 0.025 mg. of lead is treated in the same way with the quantities of reagents used in the test. Iron-Dissolve 2 grams in 20 cc. of water, add 5 drops of nitric acid, and boil for about a minute. Cool, add 2 cc. of hydrochloric acid, dilute to 25 cc., and add 2 cc. of 10 per cent ammonium thiocyanate solution. Any red color should not be greater than is produced when a quantity of an iron salt containing 0.01 mg. ofi ron is treated in the same way.
Alcohol, Ethyl REQUIR~~ASENTS Asshy-Not less than 95 per cent by volume. Solubility i n Water-To pass test. Residue on Evaporafion-Not more than 0.001 per cent.
Vol. 20, No. 9
Acetone, Isopropyl Alcohol-To pass test (limit about 0.001 per cent acetone, 0.003 per cent isopropyl alcohol). Acidity-Not more than 0.003 per cent as CHx.COOH. Alkalinity-Not more than 0.003 per cent as NHI. Fusel Oil-To pass test. Methanol-To pass test (limit about 0.1 per cent). Substances Darkened by Sulfuric Acrd-To pass test. Substances Reducing Permanganate-To pass test.
TESTS Assay-The specific gravity at 25'/25' C. should not be more than 0.810. Solubility i n Water-Mix 15 cc. with 45 cc. of water and allow to stand for 1 hour. The mixture should be as clear as an equal volume of the water. Residue on Evaporation-Evaporate 60 cc. on the water bath and dry for one-half hour a t 105" to 110' C. The residue should not weigh more than 0.0005 gram. Acetone, Isopropyl Alcohol-Dilute 1 cc. with 1 cc. of water, add 1 cc. of a saturated solution of disodium hydrogen phosphate and 3 cc. of a saturated solution of potassium permanganate. Warm the mixture to 45" or 50' C. and allow to stand till the permanganate color is discharged. Add 3 cc. of a 10 per cent solution of sodium hydroxide and 1 cc. of a 1 per cent solution of furfural, filter, allow the filtrate to stand for 10 minutes, and add 3 cc. of hydrochloric acid to 1 cc. of the filtrate. N o pink color should be produced. Acidily-To 25 cc. of water and 10 cc. of alcohol in a glass-stoppered Bask add 0.50 cc. of phenolphthalein solution and add 0.02 N sodium hydroxide until a slight pink color persists after shaking for one-half minute. Add 25 cc. of the sample, mix well, and titrate with 0.02 N sodium hydroxide until the pink color is reproduced. Not more than 0.5 cc. of the hydroxide should be required, Alkalinity-Dilute 25 cc. with 25 cc. of water and add 1 drop of methyl red indicator solution. Not more than 0.20 cc. of 0.02 N sulfuric acid should be required to produce a pink color. Fusel Oil-Mix 10 cc. with 5 cc. of water and 1 cc. of glycerol and allow to evaporate spontaneously from a piece of clean blotting paper. When the last traces of alcohol leave the paper no disagreeable odor should be perceptible. Methanol-Follow the directions of the U. S. Pharmacopeia X test for methanol in alcohol. Substances Darkened by Sulfuric Acid-Cool 10 cc. of sulfuric acid, contained in a small Erlenmeyer Bask, to 10' C., and add drop by drop with constant agitation 10 cc. of the alcohol. The resulting mixture should not have more than a slight brown color. Substances Reducing Permanganate-Cool 20 cc. to 15' C., add 0.1 cc. of 0.1 N potassium permanganate, and allow to stand a t 15' C. for 5 minutes. The pink color should not entirely disappear.
Alcohol, Ethyl, Absolute REQUIREMENTS Assay-Not less than 99.5 per cent by volume (about 99.2 per cent by weight). All other requirements the same as for Alcohol, Ethyl.
TESTS Assay-The
specific gravity a t 25'/25'
C. should not be more than
O.iQO0. All other tests the same as for Alcohol, Ethyl.
Calcium Chloride, Anhydrous REQUIRBMENTS Assay-Not less than 96 per cent as CaCIa. Alkalinztj-Not more than 0 020 per cent as Ca(0H)Z. Magnesium and Alkali Salts-Not more than 1.0 per cent as sulfates TESTS A s s a p w e i g h accurately about 2 grams, dissolve in water, and make to 200 cc. Transfer 25 cc. of the solution to a 200-cc. graduated flask, dilute with about 100 cc. of water, add 2 cc. of nitric acid, and slowly run in 50 cc. of 0.1 N silver nitrate. Dilute with water to the mark and shake well. Filter through a dry filter into a dry flask and reject the first 20 or 30 cc. of the filtrate. Titrate 100 cc. of the filtrate with 0.1 N ammonium thiocyanate, using ferric ammonium sulfate indicator. Alkalinity-Dissolve 5 grams in 50 cc. of water and add 2 drops of phenolphthalein indicator solution. If any pink color is produced i t should be discharged by not more than 0.3 cc. of 0.1 N hydrochloric acid. Magnesium and Alkali S a l t s D i s s o l v e 2 grams in 100 cc. of water, add 7 5 cc. of 4 per cent ammonium oxalate solution, make slightly alkaline with ammonium hydroxide, dilute to 200 cc., allow t o stand overnight, and filter. T o 100 cc. of the filtrate add 10 drops of sulfuric acid, evaporate t o dryness, and ignite gently. The ignited residue should not weigh more than 0,0100 gram after correction for any residue in the ammonium oxalate and hydroxide used.
September, 1928
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Magnesium Chloride (MgClz.6Hz0) REQUIREMENTS Insoluble Matter--Not more than 0.005 per cent. Solution in Alcohol-To pass test. Nitrale (N03)-To pass test (limit about 0,001 per cent). PhosPhale (PO4)-Xot more than 0.0005 per cent. Sulfate (SOd)-A'ot more than 0.002 per cent. Alkali Salls-To pass test (limit about 0.10 per cent). Ammonia (-NH3)-Not more than 0.002 per cent. Barium (Ba)-To pass test (limit about 0,002 per cent). Calcium (Ca)-To pass test (limit about 0.01 per cent). Heavy Meld~-To pass test (limit about 0.0005 per cent lead). Iron (Fe)-Not more than 0.0005 per cent.
TESTS Insoluble &fatier-Dissolve 10 grams in 50 cc. of watw and allow to stand on the steam bath for 1 hour. Filter through asbestos in a Gooch crucible, wash, dry at 105' to 110' C., and weigh. The weight of the residue should not exceed 0.0005 gram. Solution i n Alcohol-Dissolve 2 grams in 10 cc. of alcohol. The resulting solution should be as clear as the alcohol without the magnesium chloride. Nilrale-Dissolve 3 grams in 10 cc. of water, add 1 drop of indigo solution (1in 1000) and 10 cc. of sulfuric acid. The blue color should not entirely disappear in 5 minutes. Phosphale-To 10 grams add 15 cc. of nitric acid and evaporate to a small volume. Take up with a mixture of 5 cc. of nitric acid and 40 cc. of water and add ammonium hydroxide till a precipitate begins to form. Clear the solution with nitric acid and add 50 cc. of ammonium molybdate solution. Shake for 5 minutes a t a temperature of 40' C . and allow to stand for 1 hour. Any precipitate produced should not be greater than is produced from a quantity of alkaline phosphate containing 0.05 mg. of PO1 when treated like the sample. Suljale-Dissolve 1 gram in 10 cc. of water, add 1 cc. of 0.1 A' hydrochloric acid and 1 cc. of 11) per cent barium chloride solution. Any turbidity should not be greater than is produced by 0.02 mg. of SO4 under the same conditions. Alkali Salts-Treat 5 grams twice with 10 cc. of nitric acid, evaporating to dryness after each treatment. Carefully ignite the residue t o convert the magnesium nitrate t o oxide. Cool the residue in a desiccator, triturate well with 2 5 cc. of cold water free from carbon dioxide, transfer to a small flask, add another 25 cc. of water, and shake for 15 minutes. Filter, evaporate 10 cc. of the filtrate t o dryness, dry a t 105' to l l O o C., and weigh. The weight of the residue should not exceed 0,0010 gram. The residue may con. tain traces of calcium and magnesium. Ammonium-Dissolve 2 grams in 50 cc. of water and ;add 10 cc. of 10 per cent sodium hydroxide solution. Filter and to 30 cc. of the filtrate add 2 cc. of Nessler's solution. The color should not be greater than is produced by 0.02 mg. of NH3 in 2 5 cc. of water and 5 cc. of the sodium hydroxide upon the addition of 2 cc. of Nessler's solution. Barium-Dissolve 1 gram in 10 cc. of water and add 1 cc. of A' sulfuric acid. At the end of half an hour the solution should be no more turbid than a similar one to which no sulfuric acid has been added. Calcium-Dissolve 2 . 5 grams in 50 cc. of 95 per cent alcohol, add 25 cc. of 20 per cent sulfuric acid, and allow to stand overnight. No precipitate or turbidity should be produced. If crystals separate, warm the solution slightly. Heavy Metals-Dissolve 2 grams in 25 cc. of water, add 1 cc. of 0.1 S hydrochloric acid, and pass hydrogen sulfide through the solution. No brown color should be produced. Iron-Dissolve 2 grams in 25 cc. of water, heat to boiling, add 5 drops of nitric acid, boil a few minutes, cool, dilute to 20 cc. Add 2 cc. of hydrochloric acid and 1 cc. of 10 per cent ammonium thiocyanate. Any red color should not be greater than is produced by 0.01 mg. of iron in the same volume of solution containing the quantities of hydrochloric and nitric acids and of thiocyanate used in the test.
Methanol RECUIREXESTS
TESTS specific gravity a t 25'/25'
Boiling Range-Test according to the U. S. Pharmacopeia X , using a sample of 100 cc. Residue on Evapornlion-Evaporate 60 cc. on the water bath and dry a t 105' to 110' C. for one-half hour. The residue should not weigh more than 0.0005 gram. Solubility in Water-Mix 15 cc. with 45 cc. of water and allow to stand 1hour. The solution should be as clear as an equal volume of the water. Acetone, Aldehydes-To 1 cc. of alcohol add 4 cc. of water and 5 cc. of Nessler's solution. Any turbidity produced should not be greater than is produced by 0.010 mg. of acetone in 5 cc. of water and 5 cc. of Nessler's solution. Acidily-To 25 cc. of water and 10 cc. of alcohol in a glass-stoppered flask add 0.50 cc. of phenolphthalein solutiob and add 0.02 N sodium hydroxide until a slight pink color persists after shaking for one-half minute. Add 26 cc. of the sample, mix well, and titrate with 0.02 N sodium hydroxide until the pink color is reproduced. Not more than 0.5 cc. of the hydroxide should be required. Alkalinity-Dilute 25 cc. with 25 cc. of water and add 1 drop of methyl red indicator solution. Not more than 0.20 cc. of 0.02 N sulfuric acid should be required to produce a pink color. Ethyl Alcohol-Dilute 10 grams (12.5 cc.) with 30 cc. of water and add 10 cc. of N sodium hydroxide. Mix, add 30 cc. of 0.1 N iodine and keep the mixture a t about 40' C. for one-half hour. When observed vertically the solution should appear as free from yellow color or precipitate as a similar mixture of the sample, water, and sodium hydroxide solution to which no iodine has been added. Substances Darkened by Sulfuric Acid-Cool 10 cc. of sulfuric acid, contained in a small Erlenmeyer flask, to loo C. and add drop by drop with constant agitation 10 cc. of the sample. The resulting mixture should n,ot have more than a slight brown color. Substances Reducing Permanganate-Cool 20 cc. to 15' C., add 0.1 cc. of 0.1 N potassium permanganate, and allow to stand a t 15' C. for 5 minutes. The pink color should not entirely disappear.
Potassium Ferricyanide Re QUIREME NT s Insoluble Matter-Not more than 0.005 per cent. Chloride (C1)-Not more than 0.010 per cent. Sulfate (Sod)-To pass test (limit aboxt 0.01 per cent). Ferro Compounds--Not more than 0.05 per cent as ferrocyanide radical [Fe(CN)sl. TESTS Insoluble .Matter-Dissolve 10 grams in 50 cc. of water and heat on the water bath for 1 hour. Filter through asbestos in a Gooch crucible, wash thoroughly, dry a t 105' to 110' C.. and weigh. The weight of the residue should not exceed 0.0005 gram. Chloride-Dissolve 2 grams in 175 cc. of water, add 2.5 grams of copper sulfate crystals (free from chloride) dissolved in 2 5 cc. of water, mix thoroughly, allow to stand for 15 minutes, and filter. To 50 cc. of the filtrate add 2 cc. of nitric acid and 1cc. of 0.1 N silver nitrate. Any turbidity should not be greater than is produced by 0.05 mg. of chloride ion in an equal volume of solution containing the quantities of acid and silver nitrate used i n the test. SuZfale-Dissolve 5 grams in 100 cc. of water without heating, filter, and to the filtrate add 5 drops of glacial acetic acid and 5 cc. of 10 per cent barium chloride solution. Stir and pour into a ATessle: tube for observation. S o turbidity s h o d d be produced in 10 minutes. Filter, wash thoroughly, ignite, and weigh. The weight of the ignited residue should not exceed 0,0010 gram. Ferro Compounds-Dissolve 4 grams in 400 cc. of water, add 10 cc. of 20 per cent sulfuric acid, and immediately follow with 0.1 cc. of 0.1 potassium permanganate. The solution after stirring should retain a pink tint in comparison with a control test made with the same quantities of ferricyanide, water, and acid.
Potassium Ferrocyanide REQUIREMESTS
A ppearance-Clear and colorless. Assay-Xot less than 99.5 per cent by volume. Boiling Range-From 65' to 67' C. Residue on Evaporation-Not more than 0.001 per cent. Solubility in Water-To pass test. .-1cetone, Aldehydes-.To pass test (limit about 0,001 per cent acetone). Acidity--Not more than 0.003 per cent as CH3COOH. Alkalinity-Not more than 0.003 per cent as "3. Ethyl Alcohol-To pass test (limit about 1 per cent as CzHsOH). Substances Darkened by Sulfuric Acid-To pass test. Subslances Reducing Permanganafe-To pass test. Assay-The 0.791.
981
C. should not be more than
Insoluble Matler-N70t more than 0.010 per cent. Chloride (C1)-Not more than 0.010 per cent. Sulfate (SOd)-To pass test (limit about 0.01 per cent)
TESTS Insoluble .Malfer-Dissolve 5 grams in 50 cc. of water and heat on the water bath for 1 hour. Filter through asbestos in a Gooch crucible, wash thoroughly, dry a t 105' to 110' C., and weigh. The weight of the residue should not exceed 0.0005 gram. Chloride-Dissolve 2 grams in 176 cc. of water, add 2.5 grams of copper sulfate crystals (free from chloride) dissolved in 25 cc. of water, mix thoroughly, allow to stand for 15 minutes, and filter. T o 50 cc. of the filtrate add 2 cc. of nitric acid and 1cc. of 0.1 N silver nitrate. Any turbidity should not be greater than is produced by 0.05 mg. of chloride ion in an equal volume of solution containing the quantities of acid and silver nitrate used in the test.
INDUSTRIAL AND ENGINEERING CHEMISTRY
982
Sulfate-Dissolve 5 gramsin 100 cc. of water without heating, filter,and t o the filtrate add 5 drops of glacial acetic acid and 5 cc. of 10 per cent barium chloride solution. Stir and pour into a Nessler tube for observation. No turbidity should be produced in 10 minutes. Filter, wash thoroughly, ignite, and weigh. The weight of the ignited residue should not exceed 0.0010 gram.
Sodium Bisulfate Fused (NaHSOJ REQUIR&MENTS Acidity-Not less than 39.0per cent as H90'. Insoluble Matter and Ammonium Hydroxide Precipitate-Not more than 0.010 per cent. Chloride (CI)-Not more than 0.002 per cent. Phosphate (PO4)-Not more than 0.001 per cent. Arsenic (As)-Not more than 0.0005 per cent. Calcium and Magnesium P r e c i p i t a t c N o t more than 0.005 per cent. Heavy Metals-To pass test (limit about 0.0005per cent lead). Iron (Fe)-Not more than 0.002per cent.
TESTS Acidity-Dissolve 4 grams in 50 cc. of water and titrate with normal alkali. Insoluble Matter and Ammonium Hydroxide Precipitate-Dissolve 10 grams in 100 cc. of water, add ammonium hydroxide till the solution is alkaline t o methyl red, and boil for 1 minute. Filter through asbestos in a Gooch crucible, wash thoroughly, and dry 1 hour at 105' to 110' C. The weight of the precipitate should not be more than 0.0010 gram. Chloride-Dissolve 1 gram in 15 cc. of water, add 2 cc. of nitric acid and 1 cc. of 0.1 N silver nitrate. Any turbidity should not be greater than is produced by 0.02 mg. of chloride ion in an equal volume of solution containing the quantities of reagents used in the test. Phosphate-Dissolve 5 grams in 50 CC. of water, add 10 cc. of nitric acid, and nearly neutralize with ammonium hydroxide. Add 50 cc. of ammonium molybdate solution, shake (at about 40' C.) for 5 minutes, and allow to stand one-half hour. Any precipitate formed should not be greater than is produced when a quantity of an alkali phosphate containing 0.05 mg. of phosphate (POI) is treated according t o the above procedure. Arsenic-Determine on a 2-gram sample by the modified Gutzeit method. Calcium and Magnesium P r e c i p i t a t c T o t h e filtrate from the test for insoluble matter (without the washings) add 5 cc. of 4 per cent ammonium oxalate solution, 3 cc. of 10 per cent ammonium phosphate solution, and 10 cc. of ammonium hydroxide. If any precipitate forms on standing overnight, filter, wash thoroughly with water containing 2.5 per cent of "3, ignite, and weigh. The weight should not be more than 0.0005 gram, Heavy Metals-Dissolve 2 grams in 25 cc. of water, add 2 cc. of hydrochloric acid, and boil gently for 10 minutes. Cool, neutralize to litmus with ammonium hydroxide, add 1 cc. of 0.1 N hydrochloric acid, dilute t o 25 cc., and pass hydrogen sulfide through the solution. N o brown color should appear. Iron-Add ammonium hydroxide t o the solution obtained in the test for heavy metals till i t is slightly alkaline. Any green color produced should not be greater than is produced b y 0.04 mg. of iron in an equal volume of alkaline sulfide solution.
.
Sodium Chloride REQUIWMENTS Insoluble Matter-Not more than 0.005 per cent. Neutrality-To pass test. Chlorate and Nitrate-To pass test (limit about 0.002 per cent ClOa). Nitrogen Compounds (as N)-Not more than 0.001per cent. Phosphate (POd)-Not more than 0.0005 per cent. Sulfate (SO4)-To pass test (limit about 0.001 per cent). Ammonium Hydroxide Precipitate-To pass test. Barium (Ba)-To pass test (limit about 0.001 per cent). Calcium and Magnesium Precipitate-Not more than 0.005 per cent. Heavy Metals (as Ag or Pb)-To pass test (limit about 0.0005 per cent silver or lead). Iron (Fe)-Not more than 0.0003 per cent. Potassium (K)-Not more than 0.01 per cent.
TESTS Insoluble Matter-Dissolve 10 grams in 100 cc. of warm water and allow to stand on the steam bath for 1 hour. Filter through asbestos in a Gooch crucible, wash, dry a t 105O t o 110' C., and weigh. The weight of the residue should not exceed 0.0005 gram. Neutrality-To a solution of 5 grams in 50 cc. of water free from carbon dioxide add 3 drops of phenolphthalein solution. N o pink color should be produced; the addition of 1 drop of 0.1 N sodium hydroxide should produce a pink color. Chlorate and NitrateDissolve 1 gram in 10 cc. of water, add 1 drop of indigo solution (1 in 1000) and 10 cc. of sulfuric acid. The blue color should not be entirely destroyed in 10 minutes.
Vol. 20, No. 9
Nitrogen Compounds-Dissolve 2 grams in 40 cc. of water in a flask, add 10 cc. of 10 per cent sodium hydroxide solution and about 0.5 gram of aluminum wire in small pieces. Allow to stand for 3 hours protected against loss or access of ammonia. Decant 25 cc. and add 2 cc. of Nessler's solution. Any color produced should not be greater than is produced by a quantity of an ammonium salt containing 0.01 mg. of nitrogen. Correction must be made for any nitrogen in the reagents used. Phosphate-Dissolve 10 grams in 40 cc. of water and 15 cc. of nitric acid. Evaporate to dryness, take up in 15 cc. of water and 5 cc. of nitric acid, and evaporate to dryness again. Take up with 10 cc. of nitric acid, dilute with 50 cc. of water, and nearly neutralize with ammonium hydroxide. Add 50 cc. of ammonium molybdate solution, shake (at about 40' C.) for 5 minutes, and allow to stand half an hour. Any precipitate formed should he less than is produced when an alkaline phosphate containing 0.05 mg. of phosphate (Pod is treated according to the above procedure. Sulfate-Dissolve 10 grams in 100 cc. of water, add 1 cc. of hydrochloric acid, heat to boiling, add 5 cc. of 10 per cent barium chloride, and allow to stand overnight. No turbidity or precipitate should be produced. Ammonium Hydroxide Precipitate-Dissolve 10 grams in about 100 cc, of water, add a few drops of ammonium hydroxide, and boil gently in a covered beaker till the ammonia is expelled. No precipitate should be formed. Barium-Dissolve 4 grams in 20 cc. of water, filter if necessary, and divide in two portions. T o one portion add 2 cc. of 10 per cent sulfuric acid and to the other add 2 cc. of water. The solutions should be equally clear a t the end of 2 hours. Calcium and Magnesium Precipitate-To the filtrate obtained in the test for ammonium hydroxide precipitate add 5 cc. of 4 per cent ammonium oxalate solution, 2 cc. of 10 per cent ammonium phosphate solution, and 20 cc. of ammonium hydroxide, and allow t o stand overnight. If a precipitate is formed, filter through a small paper, wash with water containing 1 per cent of ammonia, ignite, and weigh. The weight should not exceed 0.0005 gram. Heavy MetalsDissolve 2 grams in 20 cc. of water and pass hydrogen sulfide through the solution. The solution should be no darker than the same volume of distilled water through which hydrogen sulfide has been passed. Iron-To the solution tested for heavy metals add ammonium hydroxide till i t is alkaline t o litmus. Any greenish color should not be greater than is produced by 0.006 mg. of iron in an equal volume of alkaline sulfide solution. Potassium-Dissolve 5 grams in 20 cc. of water, add 5 cc. of sodium cobaltinitrite solution, and allow t o stand overnight. (The sodium cobaltinitrite solution is made b y dissolving 25 grams NaNOz in 50 cc. of water and then adding 15 cc. of 6 N HCzHaOz and 2.5 grams of Co(CzHaOz):.4HrO or an equivalent amount of nitrate or chloride. The solution is allowed t o stand overnight, filtered, and diluted to 100 cc.) Any precipitate formed should not be greater than is produced by an amount of potassium chloride equivalent to 0.50 mg. K dissolved in 20 cc. of water, treated with 5 CC. of sodium cobaltinitrite solution and allowed t o stand overnight.
Zinc Chloride WQUIR~MENTS Assay-Not less than 95 per cent ZnCL. Oxychloride-To pass test. Insoluble Matter-Not more than 0.005 per cent. Nitrate (NOa)-TO pass test (limit about 0.003 per cent). Sulfate (SO4)-Not more than 0.010 per cent. Ammonia ("a)-Not more than 0.005 per cent. Iron (Fe)-Not more than 0.001 per cent. Lead (Pb)-To pass test (limit about 0.005 per cent). Substances not Precipitated by Ammonium SuZfide-Not more than 0.20 per cent.
TESTS Assay-Weigh accurately about 0.3 gram, dissolve in about 100 cc. of water in a 200-cc. graduated flask, add 5 cc. of nitric acid and 50 cc. of 0.1 N silver nitrate. Shake vigorously, make to exactly 200 cc., mix well, and filter through a dry paper into a dry flask or beaker. Reject the first 20 cc. df the filtrate. T o 100 cc. of the filtrate add 2 cc. of ferric aplmonium sulfate indicator solution (8 grams in 100 cc.) and titrate the excess of silver with 0.1 N ammonium thiocyanate. Oxychloride-Dissolve 10 grams in 100 cc. of water. On the addition of 3 cc. of N hydrochloric acid to the solution the flocculent precipitate should entirely dissolve. Insoluble Matter-To the solution obtained in the test for oxychloride add 100 cc. of water and a few drops of hydrochloric acid. If insoluble matter is present, filter through asbestos in a Gooch crucible, wash thoroughly with water containing about 0.2 per cent of HCI, and dry a t 105' to l l O o C. The weight of the dried residue should not be more than 0.0005 gram. Nitrate-Dissolve 2 grams in 10 cc. of water, add 10 cc. of sulfuric acid and 2 drops of indigo solution (1 in l000). The blue color should not disappear in 10 minutes.
September, 1928
INDUSTRIAL A N D ENGINEERING CHEMISTRY
Sulfoic--Disralve 10 grams i n I20 cc. of water and 2 CE. of hydiofhlorie acid, heat to boiling, add 6 cc. of IO per ci-1st baciilm chloride sOlYtiOn. heat on the wvatsr bath for 2 hours, and allow to stsnd overnight. If any Wecipitaie is formed, Biter, wash with water containins a mall quantity of hydrochloric acid and then with water alone, ignite, and weigh. The weight of barium sulfate should not be more than 0.0025 gram. Ammonia-Dirroiue 1 gram io 30
