EQUIPMENT

1. Extraction racks holding ten 40 mL cylindrical glass bottles in a single row.
2. Calibrated 5 g (4 mL) soil scoop.

DIPPING PROCEDURE

1. Label each extraction rack by set number and date. Distinguish between routine and special sets.
2. Additionally label each rack in the following manner:
   1. First Rack "CK" under the first bottle
   2. Second Rack "11" under the first bottle
   3. Third Rack "21" under the first bottle
   4. Fourth Rack "31" under the first bottle
3. Place a level 5 g scoop of check soil into the first bottle of the first rack.
4. Beginning with the first soil sample in the set, place a level 5 g scoop of soil into the next bottle and continue in the same manner until all of the samples in the set have been dipped.
5. Check to make sure that the number of samples dipped matches the number of samples in the set.
6. Redip the tenth set sample and place it in rack position #39 of the fourth rack.
7. Redip the twentieth set sample and place it in rack position #40 of the fourth rack.
8. Do not place any soil in rack position #38 of the fourth rack. This position is reserved for an extraction blank.