1、F- 35-19 STDeANSI IT4-20L-ENGL I783 W O724150 0542479 54T m ANSI PH4.201-1981 Revision of ANSI PH4.201-1972 I American National Standard specification for photographic grade potassium iodide Approved January 16, 1981 Secretariat: National Association of Photographic Manufacturers, Inc T s material i
2、s r produced from American National Standard w+T 4. 7, copyright lygi , with permission of the American National Standards Institute, Inc. may be copied or reproduced in any form, electronic retrieval system or otherwise, without the prior written permission of the American National Standards Instit
3、ute, Inc., 11 West 42nd Street, New York, New York 10036. ot for resale. No part of this publication , Foreword (This Foreword is not a part of American National Standard Specification for Photographic Grade Potassium Iodide, ANSI PH4.201-1981.) This standard is one of a series that establishes the
4、min- imum criteria of purity for chemicals used in processing photographic materials. However, if the purity of a commonly available grade of chemical exceeds the min- imum criteria and if there is no economic penalty in its use, the purity requirements have been set to take ad- vantage of the highe
5、r quality material. Although the ultimate criterion for suitability of a photographic grade chemical is its successful perfor- mance in an appropriate photographic use test, the shorter, more economical tests described herein are generally adequate. This standard is a revision of American National S
6、tandard Specification for Photographic Grade Potas- sium Iodide, KI, ANSI PH4.201-1972. In this latest revision, minor changes have been made in the expres- sion of solutions and concentrations, precautions have been added, Section 2 has been expanded, and methy- lene chloride has been substituted f
7、or chloroform in the Assay procedure. 1. Scope This specification establishes criteria for the purity of photographic grade potassium iodide and describes the tests to be used to determine the purity. Page 1 of 4 pages 2. General Information 2.1 Physical Properties. Potassium iodide exists in the fo
8、rm of white crystals and has a molecular weight of 166.01. 2.2 Hazardous Properties. Potassium iodide is not haz- ardous when handled with normal precautions. 2.3 Handling and Storage. Potassium iodide should be kept in the dark to prevent decomposition into iodine and iodate. 3. Summary of Requirem
9、ents Assay (KI): Insoluble Matter, Calcium, Mag- nesium, and Ammonium Hydroxide Precipitate: Loss on Drying at 150C: Alkalinity (as KOH): Sulfide (as Na2 S): Chloride and Bromide (as Ci): Heavy Metals (as Pb): Iron (Fe): Appearance of Solution: 99 .O% min 0.5% max 0.3% max 0.05% max 0.0005% max 0.01
10、 max 0.002% max 0.002% max To pass test 4. Test Samples, Reagents, Solutions, and Hazards 4.1 Samples, Tests shall be made on samples in theiI “as received” condition. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National St
11、andards Insti. tute require that action be taken to reaffirm. revise, or withdraw this standard no later than five years from the date of publication. Purchasers of American Printed in USA National Standards may receive current information on all standards by calling or writing the American National
12、 Standards Institute. Copyright 01981 by American National Standards Institute, 143OBroadway. New York, N.Y. 10018 ANS13C481/ZSO WtE Page 2 of 4 pages 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
13、Chemical Society in 1974, wherever such specifications have been estab- lished. If no American Chemical Society specification exists, the purity shall be that generally used for care- ful analytical work. 4.2.2 Wherever water is specified in the test proce- dure, only distilled or deionized water sh
14、all 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 is expressed as normality, N. The num- ber of significant figures to which the normality is known shall be suffici
15、ent to ensure that the reagent does not limit the reliability of the test method. the concentration is expressed as grams per liter (g/L) to the appropriate number of significant figures. 4.3.4 When a solution is to be diluted, its dilution is indicated by (1 t X), meaning that one volume of reagent
16、 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 the footnotes but, in addition, the normal pre- cautions
17、required during the performance of any chem- ical procedure must be exercised at all times. 4.3.3 When a standardized solution is not required, 6.2 Procedure. Take about 0.5 gram of the sample and weigh it accurately to the nearest O. 1 mg. Dissolve the sample in 10 mL of water in a 250-mL glass-sto
18、ppered flask and add 35 mL of hydrochloric and 5 mL of methylene hloride. Titrate with 0.0500 M potassi- um iodate until the purple color which is produced dis- appears from the methylene chloride3 layer. Near the end point, add the iodate solution dropwise and shake the mixture thoroughly after eac
19、h addition. After the methylene chloride3 layer has been decolorized, allow the mixture to stand for 5 minutes and, if the methy- lene chloride3 layer develops a purple color, titrate the mixture further with the iodate solution to a new end point. (mL 0.0500 M KI03) (1.66) sample weight in grams =
20、percent KI 7. Insoluble Matter, Calcium, Magnesium, and Ammonium Hydroxide Precipitate (0.5% maximum residue) Dissolve 10.0 grams f O. 1 gram of the sample in 75 mL of water. Add 5 mL of ammonium oxalate solution4 (40 g/L), 2 mL of diammonium phosphate solution (100 g/L), and 10 mL of dilute ammoniu
21、m hydrox- (1 t 9). Allow to stand overnight. If any precipi- tate is formed, filter and wash with dilute ammonium hydroxide273 (1 t 39). Dry, ignite at 600C f 25C for 2 hours, cool in a desiccator, and weigh. The weight of the residue shall not be greater than 0.050 gram. 5. Test Procedures The test
22、 procedures described in Sections 6 through 14 shall be followed to determine whether the test sample meets the purity requirements listed in Section 3. 8. (0.3% Place 5.0 grams of the sample in a low-form glass-stop- pered weighing bottle and weigh accurately to the near- est 0.1 milligram. Dry at
23、150C for 6 hours, cool in a desiccator, and reweigh. The loss in weight shall not be greater than 0.015 gram. on Drying at 150“ 6. Assay (99.0% minimum KI) CAUTION: WEAR SAFETY GLASSES DURiNG ASSAY _- *WARNING: Avoid contact with eyes, skin, and clothing. Wash thoroughly after handling. In case of c
24、ontact, flush eyes and skin with water. Obtain medical attention immediately. WARNING: Harmful if inhaled. Avoid breathing dust, vapor, mist, and gas. Use only with adequate ventilation. If inhaled, move to fresh au. Obtain medical attention immediately. 4WARNING: Harmful if swallowed. Wash thorough
25、ly after handling. If swallowed, induce vomiting. Obtain medical atten- tion immediately. 6.1 Standard 0.0500 M Potassium Iodate Solution. Weigh 10.700 grams of potassium iodate which has been dried for 4 hours at 1 5O“C, to the nearest milli- gram. Dissolve in water and dilute to 1 liter in a volu-
26、 metric flask. Available from American Chemical Society, 1155 Sixteenth Street, NW, Washington, D.C. 20036. ANSI PH4.201-1981 i? . STD-ANSI ITLi.20L-ENGL 1781 0724150 05Li2481 LTB D Page 3 of 4 pages 9. Alkalinity (0.05% maximum as KOH) Dissolve 5.0 grams f 0.1 gram of the sample in 50 mL of carbon-
27、dioxide-free water. Add 3 drops of phenol- phthalein indicator and titrate with 0.1 N hydrochlo- ric acid23 to discharge the pink color. (mL HC1) (N) (1.1 ) = percent KOH 10. Sulfide (0.0005% maximum as Na2 S) 10.1 Sulfide Standard (1 mL = 0.005 mg NazS). Dis- solve 0.500 gram of sodium sulfide (Na2
28、S) or 1.500 grams of sodium sulfide nonahydrate3 (Na2 S.9H2 O) in water, dilute to 1 liter, and mix well. Dilute a 10-mL aliquot of this solution to 1 liter and mix well. Prepare solutions freshly as needed, using freshly boiled and cooled water. 10.2 Alkaline Lead Solution. Add a sodium hydroxide s
29、olution (100 g/L) to a lead acetate3 Pb(C2H302)2 .3Hz solution (100 g/L) to dissolve the precipitate that is formed and provide a slight excess of sodium hydroxide. 10.3 Procedure. Dissolve 5.0 grams f 0.1 gram of the sample in 25 mL of water in a 100-mL beaker. Pipet 5 mL of the Sulfide Standard in
30、to a second 100-mL beaker and dilute with 20 mL of water. Treat both the sample and the standard solutions as follows: Add 2 mL of the alkaline lead solution, dilute to 50 mL, mix well, and transfer to Nessler color comparison tubes. Any color produced in the treated sample solu- tion shall not exce
31、ed that produced in the treated Sulfide Standard solution. 1 1. Chloride and Bromide (0.01% maximum as Ci) 1 1.1 Chloride Standard (1 mL = 0.001 mg Ci). Dis- solve 0.165 gram f 0.001 gram of sodium chloride in water, dilute to 1 liter, and mix well. Dilute a IO-mL aliquot of this solution to 1 liter
32、 with water and mix well. 11.2 Procedure. Dissolve 1 .O gram f O. 1 gram of the sample in 100 mL of water in a 250-mL conical flask. Add 1 mL of hydrogen peroxide (30% reagent) and 1 DANGER: Corrosive; causes burns. Avoid contact with eyes, skin, and clothing. Use with adequate ventilation. In case
33、of contact. flush with water. Obtain medical attention immediately. 1 mL phosphoric acid.2 Heat to boiling and boil gently until all the iodine is expelled and the solution is color- less. Cool, wash down the sides of the flask, and add 0.5 mL of hydrogen peroxide (30% reagent). If an iodine color d
34、evelops, boil until the solution is color- less and then for 10 minutes longer. If no color devel- ops, boil for 10 minutes. Cool and dilute to 100 mL with water. Dilute a 10-mL aliquot to 25 mL with water. Also dilute a IO-mL aliquot of the Chloride Standard to 25 mL with water. Treat both the samp
35、le and the standard solutions as follows, preparing both at the same time and comparing them within 5 minutes after the final mixing: Add 1 mL of nitric acid and 0.5 mL ofsilver nitrate (100 g/L),mix well, and trans- fer to Nessler color comparison tubes. Any turbidity produced in the treated sample
36、 solution shall not ex- ceed that produced in the treated Chloride Standard solution. 12. Heavy Metals (0.002% maximum as Pb) 12.1 Heavy Metals Standard (1 mL = 0.01 mg Pb). Dis- solve 1.8 gramsoflead acetate3 Pb(CZH30z)2 -3Hz01 in water, transfer to a 1-liter volumetric flask, dilute to the mark wi
37、th water, and mix well. Pipet a 10-mL ali- quot into a 1-liter volumetric flask, dilute to the mark with water, and mix well. 12.2 Procedure. Dissolve 2.5 grams f 0.1 gram of the sample in 25 mL of water in a 100-mL beaker. Pipet 5 mL of the Heavy Metals Standard into a second 100- mL beaker and dil
38、ute with 20 mL of water. Treat both the sample and the standard solutions as follows: Add 1 mL of dilute hydrochloric (1 + 99) and 5 mL of hydrogen sulfide water,6 dilute to 50 mL, mix well, and transfer to Nessler color comparison tubes. Any color produced in the treated sample solution shall not e
39、xceed that produced in the treated Heavy Metals Stan- dard solution. 13. Iron (0.002% maximum as Fe) 13.1 Iron Standard (1 mL = 0.01 mg Fe). Dissolve 0.70 grain f 0.05 gram of ferrous ammonium sulfate Fe(NH,)z(S04)z .6HzO in 50 mL of water and 20 mL of dilute sulfuric acid (1 + 15). Transfer to a a-
40、liter volumetric flask, dilute to the mark with water, 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. ANSI PH4.201-1981 Page 4 of 4 pages and mix well. Pipet a 10-mL aliq
41、uot of this solution into a 100-mL volumetric flask, dilute to the mark with water, and mix well. 13.2 Reagents Acetate Buffer. Add 23 grams Of anhy- drous sodium acetate to 60 mL of dilute acetic acid (1 + 8) and dilute to 1 liter with water. Adjust the final pH of the solution to 5.0 f 0.1 with di
42、lute acetic acid or sodium hydroxide solution (100 g/L). 13.2.2 1,lO-Phenanthrdine (o-Phenanthroline) Mixture. Thoroughly mix equal parts of an aqueous solution of 1 ,lo-phenanthroline (1 g/L), an aqueous solution of hydroxylamine hydrochloride2 (1 O0 g/L), and pH 5 acetate buffer. 13.3 Procedure. D
43、issolve 2.5 grams fO.1 gram of the sample in 25 mL of water. Add 20 mL of water to a 5-mL aliquot of the Iron Standard. Treat both the Sam- ple and the standard solutions as follows: Add 5 mL of the 1,lO-phenanthroline mixture, dilute to 50 mL with water, and mix well. Let stand for 10 minutes and t
44、ransfer to Nessler color comparison tubes. Any color produced in the treated sample solution shall not ex- ceed that produced in the treated Iron Standard solution. 13*2*1 pH 14. Appearance of Solution (To pass test) A freshly prepared solution containing 200 grams of the sample per liter in water shall be clear and colorless. A slight turbidity or flocculence may be disregarded. “ I ANSI PH4.201-1981 .- A i-
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