Part I Speciic tions for Benzidine Dihydrochloride Dextrose (Anhydrous) Ethyl Acetate Gold Chloride Isopropyl Alcohol Nickel Sulfate Phosphoric Acid (3Ieta) Pyridine Sodium Diethyldithiocarba mate Strontium Kitrate
Recommended S pe c if icat io ns For Reagent Chemicals Appendix to “Reagent Chemicals, American Chemical Society Specifications, 1950”
Part II Changes in Specifications Published Previously
Committee o n Analytical Reagents American Chemical Society EDWARD WICHERS, Chairman, National Bureau of Standards, Washington 25, D. C. S . E. Q. ASHLEY F. S. EISENHAUER A. Q. BUTLER R. A. OSBORN B . L. CLARKE J. F. ROSS W. D. COLLINS J. P. WOLF
HIS report contains recommended specifications for ten reagent chemicals not inT cluded in the book, "Reagent Chemicals, American Chemical Society Specifications, 1950," and a considerable number of recommended changes in the specifications published in that book. The committee will recommend to the Council of the Society at its meeting in March 1953 that these new specifications and revisions of previously published specifications be officially approved in the same manner as the text of the above-mentioned book was approved on April 10, 1950. If so approved, the complete specifications contained herein will be considered to be official specifications of the American Chemical Society, effective from July 1, 1953, and the partial ones will be similarly considered to constitute official revisions of the pertinent parts of specifications previously approved by the Society. The material in this report should be regarded as an appendix to the 1950 volume, whose introductory text relating to Definitions, Procedures, and Standards should be consulted for general information on the interpretation of requirements and on the conduct of methods of test.
Part 1. New Specifications same manner but substituting 1 mi. of water for the 1 nil. of diluted blood solution. The solution of the sample must be freshly prepared for this test'.
Benzidine Dihydrochloride Formula Wt. 257.16
CuHuXs.2HCl Requirements
Dextrose, Anhydrous
Insoluble matter. Kot more than 0.0207~. Residue after ignition. Not more than 0.050%. Sulfate (SO,). Kot more than 0.015%. Sensitivity for detecting blood. To pass test.
CBH1SOO
Formula W t . 180.18
Requirements
Specifi: rotation [ a ] 'do, S o t less tlian 52.5" nor more tlian 53.0 . Inqoluble matter. S o t more than 0.00570. Loss on drying at IOj' C. S o t more than 0.20%. Residue after ignition. S o t more t,han 0.030%. Acid ( a s HC,H,O,). S o t more than 0.01570. Chloride ((21). h-ot more than 0.01070. Sulfate and sulfite (as SO,). S o t more than 0.005%
Tests Insoluble Matter.
Dissolve 5 grams in 200 ml. of water and allow to stand on the steam bath for 1 hour. Filter t,hrough a tared filtering crucible, wash thoroughly, and dry at, 105" C. The weight of t h e residue should not exceed 0.0010 gram. Residue after Ignition. Ignite 2 grams in a tared crucible until thoroughly charred, cool, and cautiously add 1 ml. of sulfuric acid. Evaporate the acid and cautiously ignite the residue at the lowest effective temperature for complete comb u d o n of the carbon. The weight of the ignited residue should not exceed 0.0010 gram. Sulfate. Moisten 1 gram wit,h 10 ml. of 10% sodium carbonate solution, evaporate to dryness, and carefullj- ignite, prot,ecting from sulfur in the flame. Treat the residue with 20 ml. of water and 2 ml. of 30% hydrogen peroxide and heat, on t,he steam bath for 15 minutes. Add 5 ml. of hydrochloric acid and evaporate to dryness on the steam bath. Dissolve the residue in 10 ml. of water, filter, and wash to a volume of 25 ml. T o 10 ml. of this solution add 1 ml. of 19) and 1 ml. of barium di1ut.e hydrochloric acid (1 chloride reagent solution. Any turbidity should not exceed that in a control prepared as follows: Treat' 10 ml. of 10% sodium carbonate solution with 2 ml. of 30% hydrogen peroxide and 5 ml. of hydrochloric acid and evaporate t o dryness on the steam bath. Dissolve the residue in 25 ml. of water. T o 10 ml. add 0.06 mg. of sulfate, 1 ml. of dilute hydrochloric acid (1 19), and 1 ml. of barium chloride reagent solution. Sensitivity for Detecting Blood. Dissolve 1 gram in 100 ml. of water, wit,hout heat'ing. Dilute 0.10 ml. of blood with water to 100 ml. and dilute a 1-ml. aliquot of this solution to 500 ml. T o 1 ml. of the latter solution in a test tube add in the order named, with mixing after each addit'ion: 1 ml. of the solution of the sample, 1 ml. of diluted 30% hydrogen 9), and 1 ml. of 170sodium acetate solution. peroxide (1 After 1 minut,e the mixed solution should show a distinct blue color when compared with a blank prepared in the
Arsenic (As). X o t more than 0.0001%. Heavy metals (as P b ) . N o t more than 0.0005%. Iron (Fe). S o t inore thon O.O005Cl,. Tests Specific Rotation.
Weigh accurately about 10 grams and dissolve in 90 ml. of water in a 100-ml. volumetric flask. Add 0.2 ml. of ammonium hydroxide and dilute t o volumc at 25' C. Observe the optical rotation in a polarimeter at 25" C. using sodium light, and calculat'e the specific rotation. I t should not be less than +52.5" nor more than +53.0". Insoluble Matter. Dissolve 20 grams in 150 nil. of water and digest on the steam bath for 1 hour. Filter through a tared filtering crucible, wash thoroughly, and dry at 105" C. The weight of the residue should not exceed 0.0010 gram. Loss on Drying. Weigh accurately about 1 gram and dry at 105" C. for G hours. The loss in weight should not' exceed 0.20%. Residue after Ignition. Gently ignite 4 grams until charred. Cool, moisten the char with 2 ml. of sulfuric acid, and reignite slowly, finally a t a dull red heat, to constant weight. The weight of the ignited residue should not exceed 0.0012 gram. Acid. To 100 ml. of carbon dioxide-free water add 2 drops of phenolphthalein indicator solution and 0.02 A' sodium hydroxide until a pink color is produced. Dissolve 10 grams of the sample in this solution and titrate with 0.02 N sodium hydroxide to the same end point. Not more than 1.25 ml. should be required. Chloride. Dissolre 1 gram in 50 nil. of water. Dilute 5 ml. of the xoliition to 25 mi. and add 1 nil. of nitric acid and
-+
+
+
366
V O L U M E 25, N O . 2, F E B R U A R Y 1 9 5 3
1 ml. of silver nitrate reagent solution. Any turbidity should not exceed that produced by 0.01 mg. of chloride ion in an equal volume of solution containing the quant,ities of reagents used in the test. Sulfate and Sulfite. Dissolve 1 gram in 10 nil. of mater. Add 1 ml. of bromine water and boil. Cool and add 1 ml. of 19) and 1 ml. of barium dilute hydrochloric acid ( 1 chloride reagent solution. -4ny turbidity, after 10 minutes, should not exceed that produced by 0.05 mg. of sulfate (SO4) in an equal volume of solution containing the quantities of hydrochloric acid and barium chloride used in the test. Starch. Dissolve 1 gram in 10 ml. of water and add 1 drop of 0.1 N iodinc. S o blue color should appear. Arsenic. Determine the arsenic in 2 grams by the Gutzeit mcthod. The amount of stain should not exceed that prod\icc(l 11y 0.002 mg. of arsenic (As). Heavy Metals. Dissolve 6 grams in water and dilute to 42 nil. To a 7-ml. portion add 0.02 mg. of lead and 1 ml. of 1 acetic acid and dilute to 40 ml. T o the remaining portion add 1 ml. of 1 A' acetic acid and dilute to 40 ml. Add 10 ml. of hydrogen sulfide water to each. The color in the snmple solution should not exceed that in the control. Iron. Dissolve 2 grams in 40 ml. of water and 2 i d . of hl\drochloric acid, dilute to 50 ml., and add 30 to 50 mg. of ammonium persulfate crystals and 3 ml. of ammonium thiocyanate reagent, solution. Any red color should not exceed that produced by 0.01 mg. of iron in an equal volume of solution containing the quantities of reagents used in the teat.
+
367
Gold Chloride Chloroauric Acid
HAuCL.3HzO
Formula R t . 394.08
Requirements
Insoluble in ether. Not more than O.lOc/o. Assay S o t less than 49.070 Bu. Alkalies and other metals (as sulfates) S o t mole than 0 20%. Tests Insoluble in Ether. Weigh accurately about 1 gram. Add 10 ml. of ether, allow to stand for 10 minutes, Lvith occasional
stirring, filter through a tared filtering crucible of fine porosity, wash with small portions of ether, and dry at 105" C. Retain the filtrate and washings. The weight of the residue should not exceed 0.10%. Assay. Evaporate the solution from the test for Insoluble in ether to dryness or a sirupy residue. Take up the residue in 100 ml. of dilute hydrochloric acid ( 1 19), disregarding any undissolved material. Add 10 ml. of sulfurous acid and digest on the steam bath until t'he precipitate is well coagulated. Filter, wash with dilute hydrochloric acid ( 1 99), and ignite. Retain the filtrate and washings. The weight of the residue should not be less than 49.0% of the weight of the sample. Alkalies and Other Metals (as Sulfates). Evaporate the filtrate and washings from the Assay and ignite cautiously. The weight of the residue should not exceed 0.20%.
+
+
Eth y I Ace ta+e CII~COOCPHRequirements Specific giavitv < i t 2 5 " / 2 5 " C
Isopropanol
S o t less than 0896 noi more
-than 07898. Boiling range. X o t more than 0.5' C. Residue after evauoi,ation. Kot more than 0.003%. \V?iter. Not more than 0.20%. Acid (as HC,H,O,). Not more than 0.005%. Fowign esters. To pass test. Substances darkened by sulfuric acid. To pass test.
Tests Boiling Range.
Isopropyl Alcohol
Formula Wt. 88.10
Distill 100 nil. by the method described on page 5 of "Reagent Chemicals, American Chemical Society Specifications, 1950." The difference between the temperatures observed when 20 drops and 95 ml. have distilled should not, excced 0.5" C. The boiling point of pure ethyl acetate at 760-mm. mercury pressure is ii.1' C. Residue after Evaporation. Evaporate 45 ml. on the steam bath and dry at 105" C. for 1 hour. The weight of the rcsidne should not exceed 0.0012 gram. Water. Place 25 ml. of methanol in a dry titration flask and add Karl Fischer reagent to a visually determined end point,. Add 10 mi. (9 grams) of the sample, taking care to protect the content;;: of the flask from access of moisture. Stir vigorously and titrate with Karl Fischer reagent to the same end point. From the titer and volume of titration reagent consumed calculate the v a t e r content of the sample. Acid. T o 10 ml. of alcohol, add 2 drops of phenolphthalein indicator sollition, and neutralize with 0.02 X sodium hydroxide. Add 10 ml. of the sample, mix gently, and titrate with 0.02 A- sodium hydroxide until the pink color persists for 15 seconds. S o t more than 0.40 ml. should be required. Foreign Esters. E\xporare 5 ml. from clean, odorless filter paper. The final odor should not be different in character from that observed at the beginning of the test. Substances Darkened by Sulfuric Acid. Superimpose 5 ml. of ethyl acetate upon 5 ml. of sulfuric acid. S o dark coloration should hc produced at the zone of contact.
CH~CHOHCHB
Formula W t . 60.09
Requirements
Specific gravity a t 2 ? 1 ~ / 2 C. 5 ~ Kot less than 0.783. nor more than 0.785. Boiling range. Yot more than 0.5" C. Residue after evaporation. Kot more than O.OOlc/,. Solubility in water. T o pass test. Water. Not more than 0.50%. Seutrality. To pass test. Tests Boiling Range. Distill 100 ml. by the method described on page 5 of "Reagent Chemicals, American Chemical Society Specifications, 1950." The difference between the temperatures observed when 20 drops and 95 ml. have distilled should not exceed 0.5". The boiling point of pure isopropyl alcohol at iG0-mm. mercury pressure is 82.3". Residue after Evaporation. Evaporate 140 ml. on the steam bath and dry a t 105' C. for 30 minutes. The weight of the residue should not exceed 0.0011 gram. Solubility in Water. Mix 10 ml. with 40 ml. of water and allow to stand 1 hour. The solution should be as clear as nn equal volume of water. Water. Place 25 nil. of methanol in a dry titration flask and add I
