1、ANSI PHL1.205 BL1 07241150 0011113110 L1 F-5- I q ANSIJASC PH4.205-1984 Revision of ANSI PH4.205-1977 American National Standard for photography (chemicals) - 5-methyl benzotriazole 8 Approved January 24,1984 Secretariat: National Association of Photographic Manufacturers, Inc I Warning and Safety P
2、recautions I Some of the chemicals specified in the test proce- dures in this standard are caustic, toxic, or other- wise hazardous. Specific caution, warning, and danger notices are given in the footnotes but, in addition, the normal precautions required during the performance of any chemical proce
3、dure shall be exercised at all times. It is recommended that anyone using these chemicals obtains from the manufacturers pertinent information about the hazards, handling, and use of these chemicals. Such information is usually furnished by the chemical manufacturer in the form of a manufac- turers
4、material safety data sheet (OSHA Form 20 or equivalent). L I Page 1 of 4 pages Introduction (This introduction is not part of American National Standard ANSI/ASC PH4.205-1984,) This standard is one of a series that establishes criteria of purity for chemicals used in processing photographic material
5、s. 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 in this stan- dard are generally adequate. This standard is a revision of American National Standa
6、rd Specification for Photographic Grade 5-Methylbenzotriazole, ANSI PH4.205-1977. In this latest revision, the section on physical appearance has been replaced with a section on general information, minor changes in precaution notations have been made, the solution appearances test has been modified
7、, and the general format has been changed to be in agree- ment with the style outlined in the Directives for the Technical Work of the International Organization for Standardization (ISO). An American National Standard implies a consensus of those substantially concerned with its scope and provision
8、s. An American National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an American NationalStan- dard does not in any respect preclude anyone, whether he has approved the standard or not, from manufacturing, marketing, purchasing, or u
9、sing 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 wiii in no circumstances give an interpre
10、tation 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 withdrawn at any tim
11、e. 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 ap- proval. Purchasers of American National Standards may receive current information on all standards by calling or wr
12、iting the American Na- tional Standards Institute. ANSI5C58414 Copyright 01984 by American National Standards Institute, 1430 Broadway, New York, N.Y. 10018 - . ANSI PHq-205 84 0724350 OOL33L3 b Page 2 of 4 pages i. Scope This standard establishes criteria for the purity of photographic-grade 5-meth
13、ylbenzotriazole and describes the tests to be used to determine the purity. 2. General Information 2.1 Physical Properties, 5-methylbenzotriazole is a white to light tan crystalline powder. The chemical for- mulais C7H7N3 and the relative molar mass is 133.13. 2.2 Hazardous Properties. 5-methylbenzo
14、triazole is a moderate skin irritant. 2.3 Handling and Storage Conditions. 5-methylbenzo- triazole shall not be stored for prolonged periods at temperatures above 38C (100F) or exposed to rela- tive humidities greater than 75%. chemicals of a purity acceptable for the analysis. The acids and ammonia
15、 solutions referred to in all the in- structions shall be of full strength unless dilution is specified, Dilution is specified in terms of normality, N, when standardization is required. The number of significant figures to which normality is known shall be sufficient to ensure that the reagent does
16、 not limit the reliability of the test method. When dilution is indicated as (i t X), it means that one volume of the reagent or strong solution is added to X volumes of distilled water. 4.2 Water. Whenever water is specified in the test pro- cedures, only distilled water or water of at least equal
17、purity shall be used. 4.3 Glassware. All glassware subject to heating shall be of heat-resistant glass; for example, Pyrex or equiva- lent, 5. Tests 3. Summary of Requirements Assay : 98.0% (m/m) minimum Appearance of 0.1% Solution: To pass test Volatile Matter (70C): 0.5% (m/m) maximum Residue afte
18、r Ignition (600C i 25C): O. 1% maximum Identity: To pass either the melt- ing point test (79” to 84C) or have essentially the same infrared absorption curve as that of the reference spectrum NOTE: m/m = mass per mass 4. Reagents and Materials 4.1 Reagents 4.1.1 Reagents shall be handled in conformit
19、y with health and safety precautions as shown on containers or as given in other sources of such information. Proper labeling of prepared reagents includes adequate health and safety precautions. The discharge of reagents shall conform to applicable environmental regulations, 4.1.2 Reagents used in
20、the test procedures shall be certified reagent-grade chemicals and shall meet the specifications given in Reagent Chemicals, published by the American Chemical Society (ACS) in 198 1, or Available from American Chemical Society, 1155 Sixteenth Street, NiV, Washington, DC 20036. Tests shall be made o
21、n the samples in their “as re- ceived” condition, 10 shall be followed to determine whether the test sample meets the purity requirements listed in Sec- tion 3. In the last several years, there have been great im- provements in instrumentation for various analyses. Where such techniques have the equ
22、ivalent accuracy and precision, they may be used in place of the tests described in this standard. The test procedures described in Sections 6 through 6. Assay 98% (m/m) minimum as 5-methylbenzotriazole 6.1 Standard Silver Nitrate Solution (0.1 N) (16.987 g/L). Dissolve 16.987 grams of silver nitrat
23、e2 (100% purity) in 500 mL of water in a 1-liter volumetric flask. Dilute to the mark, stopper, and invert several times. Transfer this solution to a dark bottle to protect the solution from light. 6.2 Apparatus for Potentiometric Titration. Common laboratory apparatus shall be used for potentiometr
24、ic titration as well as the following: (1) Potentiometer or vacuum tube voltmeter (2) Indicator electrode - a silver electrode *WARNING; Avoid contact with eyes, skin, and clothing. Wash thoroughly after handling. In case of contact, flush eyes and skin with water. Obtain medical attention immediate
25、ly. ANSIIASC PH4.205-1984 ANSI PH4*205 84 I 072435.0 00333112 8 (3) Reference electrode - a suitable double junc- (4) Magnetic stirrer (5) Buret, Class A straight bore with 1 :5 Teflon standard tapered bore stopcock or equivalent, 50-mL capacity 6.3 Procedure. Weigh about 0.5 gram of the sample to t
26、he nearest 0.1 mg and dissolve in 100 mL of water in a 250-mL beaker (6).3 Add 10 mL of sodium acetate so- lution (100 g/L). Place this beaker containing a stirring bar on the magnetic stirrer (4). Place electrodes into the beaker solution. Connect the indicator electrode (2) to the proper terminal
27、of the potentiometer or vacuum tube voltmeter (1) and the reference electrode (3) to the other terminal. Titrate potentiometrically with 0.1 N silver nitrate2 solution (6.1) added from a buret (5). As the end point is approached, add the 0.1 N silver nitrate solution in 0.1 mL increments. In a simil
28、ar manner, titrate a blank consisting of the same reagents as used above but without the sample. Plot the titration curves and determine the inflection points. Obtain the net volume of 0.1 N silver nitrate (AgN03). Percent 5 -methylb enzotriazole tion electrode having a potassium nitrate bridge (6)
29、Glass beaker, 250-mL capacity - (net mLAgN03) (N) (13.313) - sample weight in grams whereN= normality of silver nitrate solution 7. Appearance of O. 1% Solution (To pass test) Dissolve 1-gram portions of the sample in 1000 mL each of warm (about 50C) water and dilute sodium hydroxide4 (100 g/L) solu
30、tion. Both solutions shail be clear and free from sediment, A slight haze may be disregarded. 8. Residue after Ignition at 600“ C f 25“ C 0.1% (m/m) maximum Weigh 2.0 grams of the sample to the nearest 0.1 mg in a previously weighed platinum crucible. Incinerate carefully and then ignite the residue
31、 at 600C f 25C for 15 minutes, taking care that no particles are swept Single numbers in parentheses refer to the listing in 6.2. DANGER: Corrosive, causes burns. Avoid contact with eyes, skin, and clothing. Wash thoroughly after handling. In case of contact, flush eyes and skin with water. Obtain m
32、edical atten- tion immediately. Page 3 of 4 pages out of the crucible. Cool in a desiccator and weigh the crucible and contents to the nearest 0.1 mg. Percent residue after ignition = m3 - ml X 100 m2 -m1 where ml =.mass, in grams, of the empty crucible m2 = mass, in grams, of the crucible and test
33、sample m3 = mass, in grams, of the crucible and residue 9. Volatile Matter at 70C 0.5% (m/m) maximum Weigh about 2 grams of the sample to the nearest 0.1 mg into a previously weighed low-form, glass- stoppered weighing bottle. Dry at 70C for 5 hours. Cool in a desiccator and weigh to the nearest 0.1
34、 mg, Percent volatile matter at 70C = m - m3 X 100 m2 -m1 where ml = mass, in grams, of the weighing bottle m2 = mass, in grams, of the bottle and sample m3 = mass, in grams, of the bottle and sample before drying after drying 10. Identity To pass either the melting-point test (79C to 84C) or have e
35、ssentially the same infrared absorption curve as that of the reference spectrum 10.1 Melting-Point Test. Assemble capillary-tube melt- ing-point apparatus using a thermometer that covers the range 5O0C-1OO0C. Prepare three capillary tubes and place in them: (1) the sample to be tested, (2) a sample
36、known to be 5-methylbenzotriazole, and (3) a finely ground mixture of (1) and (2) mixed in the ratio 1 : 1. Identify the tubes, attach them to the thermom- eter, and insert them in the melting-point bath. Heat the bath to approximately 6OoC, and thereafter heat at a constant rate of 1 degree per min
37、ute, stirring con- stantly. Note the melting point of the contents of each tube as indicated by the first appearance of liquefac- tion. The melting point of the mixture shall be no lower than the lower of the two samples. The melting point of the sample should be approximately 79C to 84C. 10.2 Infra
38、red Identity Test. The sample shall have the absorption characteristics of 5-methylbenzotriazole. 10.2.1 Apparatus. An infrared spectrophotometer equipped for the 2- to 16-micrometer region and acces- ANSI/ASC PH4.205-1984 Page 4 of 4 pages sory equipment for using mineral oil mull or pressed anhydr
39、ous potassium bromide plates shall be used in this test. ple to a homogeneous fine powder. Prepare a 0.5% mixture of the sample in finely ground anhydrous potassium bromide. Grind thoroughly (to approxi- mately 200 mesh). Prepare a pressed plate of the mix- ture to contain 0.8 to 1 gram of material
40、per square e inch (6.45 cm2) of die area. Record the infrared spec- trum from 2 to 16 micrometers. Make a qualitative identification by comparison of the sample curve with the anhydrous potassium bromide plate reference curve in Figure 1. As an alternative procedure, the 5-methylbenzotria- zole can
41、be ground and dispersed in mineral oil. If this is done, it is necessary to take into account the presence of interfering mineral oil absorption bands. 10.2.2 Procedure. Grind about 1 gram of the Sam- WAVE NUMBERS IN cm-I WAVE NUMBERS IN cm-1 Figure 1 Infrared Spectrum Reference Curve (5-Methylbenzotriazole in Anhydrous Potassium Bromide) ANSIIASC PH4.205-1984
