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7.1-. <br /> particle size larger than specified above, the solid <br /> material would be prepared for extraction by crushing , <br /> cutting or grinding the material so that it passes through <br /> a 9 .5 mm (0 .375 inch) sieve or , if the material is in a <br /> single piece, by subjecting the material to the "Structural <br /> Integrity Procedure" described below. <br /> 4 . The solid material obtained in Step 3 should be weighed <br /> immediately and placed in an extractor with 16 times its <br /> weight of deionized water . Do not allow the material <br /> to dry prior to weighing . For purposes of this test , an <br /> acceptable extractor is one which will impart sufficient <br /> agitation to the mixture to not only prevent stratification <br /> of the sample and extraction fluid but also insure that <br /> all sample surfaces are continuously brought into contact <br /> with well mixed extraction fluid . <br /> 5 . After the solid material and deionized water are placed <br /> in the extractor, the operator should begin agitation <br /> and measure the pH of the solution in the extractor . <br /> If the pH is greater than 5 .0, the pH of the solution <br /> should be decreased to 5 .0 + 0 .2 by adding 0. 5 N acetic <br /> acid . If the pH is equal to or less than 5 .0, no acetic <br /> acid should be added . The pH of the solution should be <br /> monitored , as described below, during the course of the <br /> extraction and if the pH rises above 5 .2, 0 .5N acetic <br /> acid should be added to bring the pH down to 5 .0 + 0 .2 . <br /> However , in an Pvent shall the aggregate amount of_$cid <br />