1、ANSI PW4.185-1987 ANSI P“4*185 87 072435U 003a1265 3 F-35-19 Revision of ANSI PH4.185-1980 for photography (chemicals) - Page 1 of 5 pages I Warning and Safety Precautions Some of the chemicals specified in the test proce- dures in this standard are corrosive, toxic, or otherwise hazardous. Specific
2、 caution, warning, and danger notices are given in the footnotes but, in addition, the normal precautions required dur- ing the performance of any chemical procedure must be exercised at all times. It is recommended that anyone using these chemicals obtain from the manufacturers pertinent informatio
3、n about the hazards, handling, and use of these chemicals. Such information is usually furnished by the chemical manufacturer in the form of a material safety data sheet (OSHA Form 20 or equivalent). I Introduction (This Introduction is not part of American National Standard PH4.185-1987 ,) This sta
4、ndard is one of a series that establishes the min- imum criteria of purity for chemicals used in processing photographic materials. Although the ultimate criterion for suitability of photographic-grade chemical is its successful perfor- mance in an appropriate use test, the shorter, more economical
5、tests described in this standard are gener- ally adequate. This standard is a revision of American National Standard Specification for Photographic Grade Ethylenediaminetetraacetic Acid (EDTA) (Ethylene- dinitri1o)tetraacetic Acid , and Its Salts, ANSI PH4.185-1980. In this latest revision, the sect
6、ion on “Reagents for Test Methods” has been renamed “Reagents, Materials, and Glassware.” The strength of standard solutions is now expressed as molarity. Also, minor changes in precaution notations have been made, and the general format has been changed to be in agree- ment with the style outlined
7、in the Directives for the Technical Work of the International Organization for Standardization (ISO). 1. Scope This standard establishes the criteria for the purity of photographic-grade ethylenediaminetetraacetic acid (EDTA) and its salts, and describes the tests to be used ationai Standard may be
8、revised or withdrawn at any time. The procedures of the American National be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of ap- ai Standards may receive current information on au standards by calling or writing the American Na- , American National Stan
9、dards Institute, 1430 Broadway, New York, N.Y. 10098 ANSI SC48714 - ANSI PH4.385 87 m 0724350 00112bb 5 H Page 2 of 5 pages to determine the purity. The salts included are diso- dium ethylenediaminetetraacetate dihydrate, tetra- sodium ethylenediaminetetraacetate dihydrate, tetra- sodium ethylenedia
10、minetetraacetate solution, tetra- potassium ethylenediaminetetraacetate solution, and diammonium ethylenediaminetetraacetate solution, hereafter respectively referred to as: Naz EDTA*2Hz O Na4 EDTA*2Hz O Na4EDTA solution K4 EDTA solution (NH4)2EDTA solution 2. General Information 2.1 Physical. EDTA,
11、 NazEDTA*2H20, and Na4EDTA *2Hz O exist in the form of white crystalline powders. The three solutions exist as off-white aqueous solutions. The chemical formula and relative molar mass of each crystalline product are: Compound Formula Molar Mass EDTA ci OH1 6N208 292.2 NazEDTAe2H20 CioHiaN2OioNaz 31
12、 2.2 Na4EDTA02H20 C 1 0H16N201 oNa4 416.2 2.2 Hazardous Properties. The Na4 EDTA solution product generally contains excess caustic and can cause permanent damage to the eyes. Contact of solutions of EDTA salts with aluminum can generate hydrogen. 2.3 Handling and Storage. All compounds shall be sto
13、red in closed containers at room temperature. 3. Summary of Requirements A summary of requirements for EDTA compounds shall be as given in Table 1. 4. Reagents, Materials, and Glassware 4.1 Reagents 4.1.1 Reagents shall be handled in conformity with health and safety precautions, as shown on contain
14、ers or as given in other sources of such information, Proper labeling of prepared reagents includes name, date of preparation, expiration date, restandardization date, and adequate health and safety precautions. The dispo- sal of reagents and all materials shall conform to appli- cable environmental
15、 regulations. ANSI PH4.185-1987 e 4.1.2 Reagentsysed in the test procedure shall be certified reagent-grade chemicals and shall meet the specifications given in Reagertt Chemicals published by the American Chemical Society (ACS) in 1981 or shall be chemicals of a purity acceptable for the analysis.
16、The acids and ammonium solutions referred to in all the instructions shall be of full strength unless dilution is specified. Dilution is specified in terms of molarity, M, when standardization is required. The number of significant figures to which molarity is known shall be ,sufficient to ensure th
17、at the reagent does not limit the reliability of the test method. When dilution is indi- cated as (1 t X), it means that one volume of the speci- fied reagent is added to X volumes of distilled water. 4.2 Water. Whenever water is specified in the test pro- cedure, only distilled water or water of at
18、 least equal purity shall be used. 4.3 Glassware. All glassware subject to heating shall be of heat-resistant glass, for example, Pyrex or equiva- lent. .I i 5. Test The tests described in Sections 6 through 11 shall be made to determine whether the test samples meet the purity requirements listed i
19、n Section 3. Tests shall be made on samples in their “as received” condition. In the last several years, there have been great im- provements in instrumentation for various analyses. Where such techniques have the equivalent precision and bias, they may be used in place of the tests de- scribed in t
20、his standard. 6, Assa y See Table 1. 6.1 Reagents 6.1.1 PAN Indicator. Dissolve 0.050 gram of l(2- pyridylazo) 2-naphthol in 75 mL of methanl., Add 25 mL of water, and mix well. J Available from American Chemical Society, 1155 Sixteenth Street, NiV, Washington, DC 20036. b DANGER: May be fatal or ca
21、use blindness if swallowed. Harmful if inhaled. If swallowed, induce vomiting. Obtain med- ical attention immediately. 3DANGER: Flammable. Keep away from heat, sparks, and flame, Use with adequate ventilation. I ANSI PH4.385 87 H 0724350 OOL3267 7 W Page 3 of 5 pages Table 1 Summary of Requirements
22、K4 EDTA Na4EDTA (“&EDTA Property EDTA Nap EDTA*2H2 O Na4 EDTA*2H2 O Solution Solution Solution Assay, minimum 99% (m/m) 98% (mim) 98% (m/m) 45% (m/m) 39% (m/m) 44% (m/m) .p pH at 25C 2.5 -2.9 4.0-5.3 10.0-11.0 No No 4.6-5.2 (saturated) requirement requirement applicable applicable applicable as KOH
23、as NaOH applicable I Free alkali Not Not Not 2.1% max 1.5% max Not Heavy metals 0.001% (m/m) 0.001% (m/m) 0.002% (m/m) 0.005% (m/m) 0.005% (m/m) 0.005% (m/m) (as Pb) max max max max max max Iron (Fe) 0.001% (mlm) 0.001% (m/m) 0.001% (m/m) 0.001% (m/m) 0.001% (m/m) .% (m/m) max max max max max max NO
24、TE: m/m = mass per mass (weight per weight) 6.1.2 Sodium Acetate Buffer (approximate pH 4.7). Dissolve 34 grams of sodium acetate trihydrate in 500 mL of water, and add 15 mL of glacial acetic aid.4, 6.1.3 Cupric Nitrate, 0.1 Molar Solution. Dissolve 24.2 grams of cupric nitrate 2-1/2 hydrate crysta
25、ls in 700 mL of water, Dilute to 1 liter in a volumetric flask. 6.1.3.1 Standardization. Weigh, to the nearest 0.0001 gram, 0.5 gram of EDTA, 100.00% (J. T. Baker, ULTREX EDTA, or equivalent), into a 250-mL beaker. Add 150 mL of water and 1 mL of sodium hydroxide4 solution (250 g/L). Stir until diss
26、olved. Add 25 mL of sodium acetate buffer (6.1.2). Adjust the pH to 4.5- 5.5 with glacial acetic acid,“,5 or sodium hydroxide4 solution (250 g/L). Heat to 95OC. Add 1 mL of PAN indicator (6.1 .i). While hot, titrate with cupric nitrate (6.1.3) to a blue-green endpoint. (weight in grams of EDTA) (3.4
27、22) mL of cupric nitrate = molarity of cupric nitrate 6,2 Apparatus, In addition to ordinary laboratory equipment, a 50-mL-capacity buret shall be used 6.3 Procedure. Weigh, to the nearest 0.0001 gram, the required sample weight shown in Table 2 for the spe- cific EDTA compound into a 250-mL beaker.
28、 Add DANGER: Corrosive, causes burns. Avoid contact with eyes, skin, and clothing. Wash thoroughly after handling, In case of contact. flush eves and skin with water. Obtain medical atten- z tion immediateiy. open flame. Use with adequate ventilation. DANGER: Combustible, Keep away from heat, sparks
29、, and 150 mL of water and 1 mL of sodium hydroxide4 solu- tion (250 g/L). Stir until dissolved. Add 25 mL of sodi- um acetate buffer (6.1.2). Adjust the pH to 4.5-5.5 with acetic 95OC. Add 1 mL of PAN indicator (6.1.1). While hot, titrate with cupric nitrate to a permanent blue-green endpoint. (mL o
30、f cupric nitrate) (molarity cupric nitrate) (A) grams of sample = EDTA compound where (A) is selected from Table 2 Table 2 Calculation Factors or sodium hydroxide? Heat to Sample Weight Required Compound mams) (A) 29.23 EDTA NapEDTAe2H20 0.6 10.1 37.23 Na4EDTA02H20 0.7 1 0.1 41.62 Na4EDTA solution 1
31、.7 10.1 38 .O2 K4EDTA solution 1.7 1 0.1 44.46 32.63 (“&EDTA solution 0.5 1 0.1 1.7 1 0.1 7. pH See Table 1. Weigh 5.0 grams of the sample into a 250-mL beaker, and add 100 mL of water. Heat to 70C, stir, cool to 25OC (disregard undissolved material), and measure the pH of the solution using a stand
32、ardized pH meter equipped with a glass-calomel electrode system. ANSI PH4.185-1987 - ANSI PH4.185 87 W O724350 00312bB 7 W Page 4 of 5 pages 8. Free Aikali 8.1 Reagents 8.1.1 Calcium Chloride, 0.5 Molar Standard Solu- tion. Dissolve 50.00 grams of chelometric standard calcium carbonate (assay 99.95%
33、 - 100.5%) in 300 mL of water by slowly adding 86 mL of hydrochloric aid, to dissolve the calcium carbonate. Heat to boil- ing to remove carbon dioxide, cool to room tempera- ture, transfer to a I-liter volumetric flask, and dilute to the mark with water. 8.1.2 Sodium Hydroxide 0.1 Molar Solution (4
34、 g/L). An analyzed reagent solution is recommended. This is commercially available from several vendors. 8.1.3 Sulfuric Acid, 0.05 Molar Solution (4.9 g/L). An analyzed reagent solution is recommended. This is commercially available from several vendors. ? 8.2 Apparatus. See 6.2. 8.3 Procedure. To a
35、 250-mL beaker containing 25 mL of the calcium chloride standard solution (8.1.1) add 25 mL of water, Add 3 to 6 drops of phenolphthalein indicator solution, and then add 0.1 M sodium hydrox- ide4 (8.1.2) until the solution becomes faintly pink. Add a few drops of 0.05 M sulfuric acid4 (8.1.3) until
36、 the color is just discharged, Weigh 6.0 grams of K4EDTA or Na4EDTA solution in a 250-mL conical flask, add 50 mL of water and the neutralized calcium chloride solution prepared above, and titrate with 0.05 M sulfuric acid4 to a faint pink endpoint. (mL H2S04) (M H2 SO4) (8) weight of sample, in gra
37、ms = percent free alkali as NaOH (mL H2 SO4) (M H2 SO4) (1 1.2) weight of sample, in grams = percent free alkali as KOH 9. Heavy Metais (as Pb) See Table 1. NOTE: Although this procedure is written to include ali the compounds listed in the Scope, refer to Table 3 for details appropriate to the spec
38、ific compound being tested. Table 3 Volume of Hydrochloric Acid and of Aliquot Hydrochloric Acid Aliquot Sample (mu mL) EDTA 0,5 20 Na2EDTAo2H20 3.0 20 Na4EDTAo2H20 4.5 10 Na4EDTA solution 2.5 4 K4EDTA solution 2.5 4 (“&EDTA solution 2.5 4 9.1 Reagents Dissolve 1.8 grams of lead acetate trihydrate b
39、(C2H302)2*3H20 in water, Dilute to 1 liter with water, and mix well. Pipet a IO-mL aliquot into a 1-liter volumetric flask, dilute to the mark with water, and mix well. 9.1.2 p-Nitrophenol Indicator Solution, Weigh 2.5 grams of p-nitrophenol, and dissolve in 1 liter of water. 9.1.3 iron Standard (1
40、mL = 0.01 mg Fe). Dissolve 0.70 gram of ferrous ammonium sulfate hexahydrate Fe(NH4)2(S04)2*6H20 in 50 mL of water, and add 20 mL of dilute sulfuric acid4 (1 t 15). Dilute to 1 liter with water, and mix well, Dilute a IO-mL aliquot of this solution to 100 mL with water, and mix well. sodium sulfide,
41、 nonahydrate6 (Na2S*9H20) in 100 mL of water. 9.1.1 Heavy Metals Standard (i mL = 0.01 mg Pb). 9.1.4 Sodium Sulfide Solution. Dissolve 5 grams of 9.2 Apparatus. Two matched Nessler color comparison cylinders, of 50-mL capacity, shall be used. 9.3 Procedure. Incinerate 5.0 grams of the powdered sampl
42、e (or evaporate to dryness and incinerate 5.0 grams of solution) in a platinum crucible, and then ignite the residue at 6OO0C f 25C for 4 hours. After cooling, dissolve the residue in 2 mL of water plus the volume of hydrochloric aid, shown in Table 3. Warm the solution if necessary to dissolve the
43、residue, and transfer the solution with washing to a 100-mL beaker. Pipet 5.0 mL of the Heavy Metals Standard (9.1 .i) into a second 100-mL beaker containing 20 mL of water. Pipet 5.0 mL of Iron Standard (9.1.3) into a third 100-mL beaker containing 200 mL of water. Treat the two standards and the s
44、ample solu- tion as follows: Add two drops of p-nitrophenol indi- cator (9.1,2), and then add dilute ammonium hydrox- ide6, (i t 9), dropwise, until the solution turns yellow. Add dilute hydrochloric aid, (1 t 99), drop- wise, until the solution becomes colorless, and then 6DANGER: Harmful if inhale
45、d. Avoid breathing dust, vapor, mist, or gas. Use only with adequate ventilation. If inhaled, move to fresh air. Obtain medical attention immediately. WARNING: Avoid contact with eyes, skin, and clothing. Wash thoroughly after handling, In case of contact, flush eyes and skin with water. Obtain medi
46、al attention immediately. ANSI PH4.185-1987 - _ ANSI PH4-345 87 0724350 OOi3269 O Page 5 of 5 pages add OS mL excess. Warm on a steam bath for 10 min- utes. Cool, dilute to 50 mL with water, and mix well. To a 20-mL aliquot of this solution containing the Heavy Metals Standard and to an aliquot of t
47、he sam- the solution containing the Iron Standard and the bal- ance of the sample solution for the iron test, Section Dilute to 50 mL with water, mix well, and transfer to Nessler color comparison tubes (9.2). Any color pro- duced in the sample solution shall not exceed that pro- duced in the treate
48、d Heavy Metals Standard solution. * ple solution having the volume shown in Table 3 (save IO), add 1 drop of sodium sulfide solution6 (9.1.4). % 10, Iron (0.001% max Fe) 10.1 Reagents 10.1.1 Acetic Acid Solution, Dilute (i + 8). Care- fully pour 10 mL of glacial acetic aid, into 80 mL of water, and
49、mix well. 10.1.2 Sodium Hydroxide Solution. Weigh 100 grams of sodium hydroxide4 and dissolve in 800 mL of water, then dilute to 1 liter with water. 10.1.3 pH 5 Acetate Buffer. Add 23 grams of anhy- drous sodium acetate to 60 mL of dilute acetic acid4 (10.1 J), and dilute to 1 liter with water. Adjust the final pH of the solution to 5.0 f 0.1 with dilute acetic acid4 (10.1 .i) or sodium hydroxide4 solution (10.1.2). 10.1.4 1 ,lO-Phenanthroline Solution. Dissolve 1 .O gram of 1 ,IO-phenanthroline in 500 mL of water and dilute to 1 liter, 10.1.5 Hy
