COMPLIANCE INFO_COMPLIANCE INFO 1983-2007

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P-C-1IIC 4.5. 1 Phenolic or cresylic acids or their salts. To 5 milliliters (ml .) of the compound in a 15-m1 . graduated centrifuge tube, add 6 N H2SO4 (sulfuric acid) until a pH of 3 is reached, as indicated by test paper. Shake the tube thoroughly and then allow to separate into two sharp layers. (At any step where separation is required, the tube may be centrifuged to speed separation.) Transfer the top layer to another centrifuge tube. Add cyclohexane to this top layer until the total volume of solution equals 5 ml . Should the cyclo- hexane layer decrease below 5 ml . at any step, additional cyclohexane should be added. Wash the cyclohexane layer with 5 ml . of the wash solution. The wash solution shall consist of 3.8 ml . ethanol and 1 .2 ml . water acidified with 1 N H2SO4 to a pH of 1-3 as shown by test paper: If at any washing ( step the solution becomes soapy or gelatinous, it should be discarded. Transfer the cyclohexane layer to another centrifuge tube, wash twice with an equal volume of water, follow by two washings with an equal volume of 3 percent sodium bicarbonate. To 1 ml . of the cyclohexane layer add 50 ml . of water. Then add 4 ml . of an 8 percent solution of sulfanilic acid con- taining 1 ml . of concentrated H2SO4 in 250 ml . of solution 'and follow by 2 ml . of a freshly prepared 8 percent by weight solution of sodium nitrite. Mix the solution and add 5 ml . of a 10 percent solution of sodium hydroxide. Mix the solution again. After three minutes , compare the solution to the comparison formula of 4.5. 19.2 which has been carried through the test. Any color other than yellow shall be taken as a positive test for phenolic or cresylic type acids. The type of coloration undesired may be determined by adding 0.5 m1 . cresol to 100 ml . of the comparison formula of 4.5.19.2. 4.5.2 Compounds of chlorine. Use ASTM D 808 (Fed. Test Method Std. No. 791 , method 5 51) with the following changes: Change paragraph 6 (e) to read: "Acidify the solution by adding nitric acid (1 : 1) , drop by drop, until acid to methyl red. Filter through quali- tative paper and collect in a second 600-m1 . beaker. Heat the solution to incipient boiling; then add 5 ml . of silver nitrate solution. Without fur- ther heating, allow the beaker and contents to stand in a dark place for 30 a minutes. If no precipitate of silver chloride has occurred, chlorine shall be considered absent. Cloudiness shall be disregarded." Delete paragraphs 6 (f) through 8 (c) of the cited test method. a 9