1、 STD-ANSI IT4-207-ENGL 1982 0724150 0542483 T7 m F-3s-/ 9 ANSI PH4.207-1982 Revision of ANSI PH4.207-1975 American National Standard specification for photographic grade sodium bromide Approved February 26, 1982 Secretariat: National Association of Photographic Manufacturers, Inc Foreword (This Fore
2、word is not a part of American National Standard Specification for Photographic Grade Sodium Bromide, ANSI PH4.207-198 2.) This is one of a series of standards that establishes cri- teria of purity for chemicals used in processing photo- graphic materials. Although the ultimate criterion for suitabi
3、lity of a photographic grade chemical is its successful use in an appropriate photographic use test, the shorter, more economical tests described herein are generally ade- quate. This standard is a revision of American National Standard Specification for Photographic Grade Sodium Bromide, ANSI PH4.2
4、07-1975. In tkis latest revision, minor changes in precaution notations have been made, the use of benzyl alcohol or nitrobenzene in the assay procedure has been eliminated, and methylene chloride has replaced carbon tetrachloride in the test for iodide. 10 N 4 n I 1. Scope This specification establ
5、ishes criteria for the purity of photographic grade sodium bromide (NaBr) and de- scribes the test to be used to determine the purity. Page i of 4 pages 2. General Information 2.1 Physical Properties. Sodium bromide is in the form of white crystals and has a molecular weight of 102.9 1. 2.2 Hazardou
6、s Properties. This material is not hazard- ous when handled with normal precautions. 3. Summary of Requirements Assay (NaBr): Insoluble Matter, Calcium, Magnesium, and Ammonium Hydroxide Precipitate: Loss on Drying at 1 05OC : Alkalinity (as NaOH): Acidity (as HBr): Chloride (as CI): Iodide (as I):
7、Sulfide (as S): Heavy Metals (as Pb): Iron (Fe): Appearance of Solution: 99 .O% min 100.6% max 0.5% max 0.5% max 0.01% max 0.01 1% max 0.2% max 0.01% max 0.0002% max 0.002% max 0.002% max To pass test An American National Standard implies a consensus of those substantially concerned with its scope a
8、nd provisions. An American National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an American National Stan- dard does not in any respect preclude anyone, whether he has approved the standard or not, from manufacturing, marketing, pur
9、chasing, or using products, processes, or procedures not conforming to the standard. American National Standards are subject to periodic review and users are cautioned to obtain the latest editions. The American National Standards Institute does not develop standards and will in no circumstancesgive
10、 an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. CAUTION NOTICE: This American National Standard may be revised or withdraw
11、n at any time. The procedures of the American National Standards Institute require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of publi- cation. Purchasers of American National Standards may receivc current information on all standards b
12、y calling or writing the American Na- tional Standards Institute. Copyright 01982 by American National Standards Institute, 1430 Broadway, New York, N.Y. 10018 ANSI5C982/3 - STD*ANSI IT4*207-ENGL 1982 Page 2 of 4 pages 4. Test Samples, Reagents, Solutions, and Hazards 4.1 Samples. Tests shall be mad
13、e on samples in the “as received” condition. 4.2 Punty of Reagents 4.2.1 Reagents used in the test procedures shall meet the specifications given in Reagent Chemicals, published by the American Chemical Society (ACS) in 1980, wherever such specifications have been established. If no ACS specificatio
14、n exists, the purity shall be that generally used for careful analytical work. only distilled or deionized water shall be used. 4.3 Strength of Solutions 4.3.1 Acids and ammonium hydroxide are full strength unless otherwise specified. 4.3.2 When a standardized solution is required, its concentration
15、 is expressed as normality, N. The num- ber of significant figures to which the normality is known shall be sufficient to ensure that the reagent does not limit the reliability of the test method. concentration is expressed as grams per liter (g/L) to the appropriate number of significant figures. i
16、ndicated by (1 t X), meaning that one volume of re- agent, or concentrated solution, is to be diluted with X volumes of water. 4.4 Hazards. Some of the chemicals specified in the test procedures are caustic, toxic, or otherwise hazard- ous. Specific caution, warning, and danger notices are given in
17、the footnotes but, in addition, the normal precautions required during the performance of any chemical procedure must be exercised at all times. 4.2.2 Wherever water is specified in the procedure, 4.3.3 When a standardized solution is not required, 4.3.4 When a solution is to be diluted, its dilutio
18、n is 5. Test Procedures The test procedures described in Sections 6 through 16 shall be followed to determine whether the test sample meets the purity requirements listed in Section 3. In the last several years, there have been great im- provements in instrumentation for various analyses. Where such
19、 techniques have the equivalent accuracy and precision, they may be used in the place of the tests described in this specification. Available from American Chemical Society, 1155 Sixteenth Street, NW, Washington, D.C. 20036. m 0724150 0542484 907 m 6. Assay (NaBr: 99.0% minimum, 100.6% maximum) Weig
20、h approximately 0.4 gram of the sample to the nearest 0.1 mg, and dissolve it in 50 mL of water. Add 50.0 mL of 0.1 N silver nitrate soiution,2 2 mL of nitric acid,3 and finally, 2 mL of saturated solution of ferric ammonium sulfate. Mix well to coagulate the sil- ver bromide and titrate excess silv
21、er nitrate2 with 0.1 N ammonium thioyanate, to the first color change. Shake the solution vigorously after the addition of each drop of ammonium thiocyanate43s near the end point. The end point is taken as the first perceptible peach color that holds for 1 minute after vigorous shaking. Percent NaBr
22、 = 50 (NAgN03)-(mLNH4SCN)(N) 10.31 grams of sample NOTE: The assay limits are based on material “as received” and are not corrected for possible sodium chloride content. The presence of sodium chloride will increase the assay value. One gram of sodium chloride is equivalent to about 1.8 grams of sod
23、ium bromide. 7. Insoluble Matter, Calcium, Magnesium, and Ammonium Hydroxide Precipitate (0.5% maximum) Dissolve 10.0 grams of the sample in 75 mL of water. Add 10 mL of ammonium oxalate solution6 (40 g/L), 4 mL of diammonium phosphate solution (100 g/L), and 20 mL of ammonium hydroxide2p7 (1 + 9).
24、Allow to stand at least 8 hours. If any precipitate is formed, filterand wash with ammonium (1 + 39). Dry the precipitate and ignite at a duLi red heat (ap- WARNING: Avoid contact with eyes, skin, and clothing. Wash thoroughly after handling. In case of contact, flush eyes and skin with water. Obtai
25、n medical attention immediately. DANGER Corrosive, causes bums. Avoid contact with eyes, skin, and clothing. Wash thoroughly after handling. In case of contact, flush with water. Obtain medical attention immedi- ately. DANGER: Harmful if swallowed. Wash thoroughly after handling. If swallowed, induc
26、e vomiting. Obtain medical at- tention immediately. thoroughly after handling. In case of contact, flush eyes and skin with water. Obtain medical attention immediately. WARNING: Harmful if swallowed. Wash thoroughly after handling. If swallowed, induce vomiting. Obtain medical at- tention immediatel
27、y. WARNING: Harmful if inhaled. Avoid breathing dust, vapor, mist, and gas. Use only with adequate ventilation. If inhaled, move to fresh ah. Obtain medical attention immediately. DANGER: Avoid contact with eyes, skin, and clothing. Wash ANSI PH4.207-1982 STDmANSI IT4*207-ENGL 1782 0724150 0542485 8
28、43 D N proximately 60OOC). Cool in a desiccator and weigh. The residue weight shall not exceed 0.05 gram. 8. Loss on Drying at 105C (0.5% maximum) Weigh, to the nearest milligram, 5.0 grams of the Sam ple in a low-form glass-stoppered weighing bottle. Dry at 105C for 4 hours, cool in a desiccator, a
29、nd reweigh. The loss in weight shall not exceed 0.025 gram. 9. Alkalinity (0.01% maximum as NaOH) Dissolve 4.0 grams of the sample in 100 mL of carbon- dioxide-free water. Add 3 drops of phenolphthalein indicator. If a pink color is produced, titrate with 0.01 N hydrochloric acid2? to discharge the
30、color. If no pink color is produced, proceed as in Section 10. (mL HCl) (N) (0.040) (100) grams of sample Percent NaOH = 10. Acidity (0.01 1% maximum as HBr) If no pink color was produced in Section 9, titrate the sample with 0.01 Nsodium hydroxide3 to the first per- manent pink color. (mL NaOH) (N)
31、 (0.0809) (1 00) grams of sample Percent HBr = 11. Chloride (0.2% maximum as Ci) Dissolve 0.5 gram of the sample in 15 mL of nitric acid3 (1 t 2) in a 125-mL conical flask. In a second 125-mL conical flask prepare a Chloride Standard con- taining 1.65 mg of sodium chloride in 15 mL of nitric acid3 (
32、I i- 2). Treat the sample solution and the Chlo- ride Standard solution as follows: Add 6 mL of 15% hydrogen peroxide solution and digest in a steam bath until the solution is colorless. NOTE: This operation should be carried out under a fume hood, as the free bromine8 driven off is a toxic vapor. W
33、ash down the sides of the flask with water, digest DANGER: Harmful if inhaled. Avoid breathing dust, vapor, mist, and gas. Use only with adequate ventilation. If inhaled, move to fresh air. Obtain medical attention immediately. Page 3 of 4 pages for an additional 15 minutes, cool, transfer to a volu
34、- metric flask, and dilute to 250 mL with water. Dilute a 10-mL aliquot in a Nessler Color Comparison tube to about 25 mL with water and add 1 mL nitric acid3 and 0.5 mL of silver nitrate solution2 (100 g/L). Dilute to 50 mL with water and mix well. Any turbidity pro- duced in the sample solution sh
35、all not exceed that pro- duced in the Chloride Standard solution. 12. Iodide (0.01% maximum as I) Dissolve 10.0 grams of the sample in a Nessler Color Comparison tube containing 25 mL of water. In another Nessler Color Comparison tube, prepare an Iodide Standard containing 1.3 mg of potassium iodide
36、 in 25 mL of water. To each tube add 1 mL of sulfuric acid (1 t 9), 0.5 mL of 0.5 molar ferric chloride solu- tion, and 1 mL of methylene hloride, and shake the mixture vigorously. Any color produced in the methy- lene chloride layer of the sample shall not exceed the color produced in the similar l
37、ayer of the Iodide Stan- dard. 13. Sulfide (0.0002% maximum as S) 13.1 Reagents 13.1.1 Alkaline Lead Solution. Dissolve 50 grams of lead acetate trihydrate7 Pb(C2H302)2 -3H201 in 450 mL of water. Add sodium hydroxide solution3 (100 g/L) until the precipitate that forms at first dis- solves and the s
38、olution is alkaline (pH 8.0 or higher). 13.1.2 Sulfide Standard Solution (1 mL= 0.001 mg S). Place several grams of sodium sulfide crystals (Na2S.9H20) on filter paper, rinse with water, and blot dry with filter paper. Weigh 1.5 grams of these crystals and dilute to 1 liter with water. Pipet 5 mL of
39、 this solution into a I-liter volumetric flask and dilute to volume with water. NOTE: Both of these sulfide solutions are unstable and should be freshly prepared before use. 13.2 Procedure. Dissolve 2.0 grams of the sample in 25 mL of water in a 50-mL Nessler Color Comparison tube. Pipet 4 mL of Sul
40、fide Standard solution into 25 mL of water in a second Nessler Color Comparison tube. Treat the Sulfide Standard solution and the Sam- ple solution as follows: Add 5 mL of sodium hydroxide solution3 (100 g/L) and mix thoroughly. Add 0.5 mL of alkaline lead solution and mix thoroughly. Dilute to 50 m
41、L with water and mix well. Any color produced ANSI PH4.207-1982 in the sample solution shall not exceed that produced in the Sulfide Standard solution. 14. Heavy Metals (0.002% maximum as Pb) 14.1 Heavy Metals Standard (1 mL = 0.005 mg Pb). Dissolve 1.8 grams of lead acetate trihydrate7 in water, di
42、lute to 1 liter, and mix well. Dilute a 5-mL aliquot of this solution to 1 liter in a volumetric flask and mix well. 14.2 Procedure. Dissolve 2.0 grams of the sample in 25 mL of water. Dilute 8 mL of the Heavy Metals Stan- dard to 25 mL with water. Treat the sample solution and Heavy Metals Standard
43、 solution as follows: Add 1 drop of p-nitrophenol indicator (2.5 g/L in water). Add, dropwise, ammonium hydroxide (1 + 9), until the solution turns yellow. Add hydrochloric acid2, (1 + 99), dropwise, until the solution becomes color- less, and then add 0.5 mL excess. Transfer to a Nessler Color Comp
44、arison tube, add 5 mL of hydrogen sulfide watery8 dilute to 50 mL with water, and mix well. Any color produced in the sample solution shall not exceed that produced in the Heavy Metals Standard solution. 15. Iron (0.002% maximum Fe) 15.1 Iron Standard(1 mL=0.005 mg Fe). Dissolve 0.70 gram of ferrous
45、 ammonium sulfate Fe(”,) (SO4)? -6H20 in 50 mL of water and 20 mL of sulfuric acid2 (1 t 15). Transfer to a 1-liter volumetric flask, dilute to the mark, and mix wellDilute a 5-mL ali- quot of this solution to 100 mL in a volumetric flask and mix well. 15.2 Reagents drous sodium acetate to 60 mL of
46、acetic acid3 (1 + 8) and dilute to 1 liter with water. Adjust the final pH of the solution to 5.0 f 0.1 with acetic acid3 (1 t 8) or sodium hydroxide solution3 (100 g/L). 15.2.2 1 ,l-Phenanthrolhe Mixture. Thoroughly mix equal parts of an aqueous solution of 1,lO-phenan- throline (1 g/L), hydroxylam
47、ine hydrochloride solu- tion2 (100 g/L), and pH 5 acetate buffer. 15.3 Procedure. Dissolve 1 .O gram of the sample in 25 mL of water. Dilute 4 mL of the Iron Standard solution to 25 mL with water. Treat the sample solu- tion and the Iron Standard solution as follows: Add 1 drop of p-nitrophenol indi
48、cator and then add, drop- wise, ammonium hydroxidez3 (1 t 9) until the solu- tion turns yellow. Add hydrochloric acid2 (1 + 99), dropwise, until the solution becomes colorless, and then add 2 mL excess. Transfer to a Nessler Color Comparison tube, add 5 mL of 1 ,lo-phenanthrolie mixture, dilute to 5
49、0 mL with water, mix well, and let stand 10 minutes. Any color produced in the sample solution shall not exceed that produced in the Iron Standard solution. 15.2.1 pH 5 Acetate Buffer. Add 23 grams of anhy- 16. Appearance of Solution (To pass test) A freshly prepared solution containing 200 grams of sample per liter of water shall be clear, colorless, and free from sediment. A slight flocculence may be dis- regarded. ANSI PH4.207-1982 from American National Standard Inc. Not for resale. No part of this publication , copyright fig&, with permission
