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The third level of sample selection further reduces the size of the subsample to 100 grams which is suitable for the chemical extraction and analysis procedure.
(a) Divide the subsample resulting from conducting the procedures in §761.353 of this part into 100 gram portions.
(b) Use a random number generator or random number table to select one 100 gram size portion as a sample for a procedure used to simulate leachate generation.
(c) Dry the 100 gram sample, selected after conducting the procedure in paragraph (b) of this section, for 10 to 15 hours in a drying oven at 100 ºC and cool it to the analytical laboratory room temperature before analysis using a procedure used to simulate leachate generation. This sample was dried previously in the larger quantity sample at the second level of sampling (§761.353(c)) and is dried a second time here (in the third level of sample selection). This dried and cooled sample must weigh at least 50 grams.
(d) If the dried and cooled sample weighs <50 grams, select additional 100 gram portions of sample one at a time by repeating the directions in paragraph (b) and (c) of this section, and add each additional 100 gram portion of sample to the first 100 gram portion until at least 50 grams of dried material is in the sample to be analyzed using a procedure used to simulate leachate generation.
[63 FR 35462 June 29, 1998]