APPENDIX I. LABORATORY PROTOCOLS FOR SAMPLE PREPARATION AND ACCELERATED SOLVENT EXTRACTION ONE-STEP CLEANUP

ERDC TN-DOER-C10

March 2000

APPENDIX I

LABORATORY PROTOCOLS FOR SAMPLE PREPARATION

AND ACCELERATED SOLVENT EXTRACTION ONE-STEP CLEANUP

Protocol I. Sediment Drying Methods.

MATERIALS AND EQUIPMENT.

Aluminum weigh pans.

Drying oven.

Aluminum foil.

60-mL precleaned jars.

Hexane.

Mortar and pestle.

Freeze-dry system.

II.

SAMPLE PREPARATION.

A. SAMPLE INFORMATION. Upon arrival, sediments are logged describing their

physical appearance, quantity/container size, and label information, and stored at 4 C until

ready for use. Samples are mixed thoroughly to obtain homogeneity before removing

subsamples for the following methods.

PERCENT SOLIDS DETERMINATION.

1) Record the weight of a hexane-rinsed aluminum pan, then tare the pan.

2) Weigh 2-4 g of wet sediment sample onto the tared pan, recording the exact

weight of the sediment, then place in 100 C drying oven overnight.

3) Reweigh the pan and dry sediment immediately upon removal from the oven to

limit the amount of moisture taken up by sediments from the atmosphere.

4) Obtain true dry sediment weights by subtracting the initial pan weight. The dry

sediment weight divided by wet sediment weight multiplied by 100 equals the

percent solids. This value is used to calculate the amount of wet sediment

required to obtain the necessary amount of dry sediment for extraction based on

the percent solids value. For example, if 8 g dry soil are needed and the percent

solids was calculated at 60 percent, (8 g/0.60) = 13.3 g wet weight would be

needed.

FREEZE-DRYING.

1) Appropriate portions of wet sediments (approximately 20-30 g) are placed in

labeled 60-mL precleaned jars. The sample should be spread evenly inside the

jar or at an angle to increase surface area before freezing the sediment in -80 C

freezer for a minimum of 2 hours.