ADDING SEDIMENT TO CELLS/COLUMNS

ERDC TN-DOER-C10

March 2000

cell in ~15-mL increments, being careful not to let column dry out. Recap

bottom end.

ADDING SEDIMENT TO CELLS/COLUMNS.

1) Mix preweighed freeze-dried sediment with diatomaceous earth (1:4 by weight).

The diatomaceous earth adsorbs any water associated with the sample that would

cause inefficient extraction.

2) Transfer the mixture to the conditioned packed cell using a small funnel with short

1/2-in. stem. Record cell serial numbers with weights of sediment. It is

important to track the cells via their serial numbers. Labeling with tape will not

work, since the cells will be exposed to high temperature. Markers are not

desirable because even permanent ink can be lost upon exposure to solvents.

3) Fill the remaining space in the cell with Ottawa Sand, leaving just enough room

for a cellulose filter.

4) Install the cellulose filter and seat snugly with the dowel.

5) Screw on the end cap by hand (do not overtighten).

6) Repeat these procedures for all samples.

7) Turn on the ASE 200, press the menu button, set up the following parameters, and

save under a method number:

Parameter

Setting

Parameter

Setting

Temperature

100 C

Flush volume

60 mL

Pressure

1,500 psi

Cycles

Static Time

5 min

Purge

60 sec

Heat

5 min

Flush percent

60 vol.

8) Select the method/schedule button and the method number under which the

program was saved. Type in the appropriate starting vial/cell number.

9) Place the cells in the tray, with the serial numbers on top (if samples are put in the

tray in the wrong direction, the extract will not pass over the SA/SG and will not

be cleaned).

10) Label the 60-mL collecting vials with the corresponding serial number on the cells

and place the vials in the correct position in the carousel.

11) Press Start. Extraction should take about 30 minutes per sample.

12) After all samples have been extracted, pour the contents of the vials into

numbered, solvent-rinsed, graduated Zymark tubes, rinsing each vial once with

approximately 2-3 mL of DCM.

SOLVENT EXCHANGE.

1) Concentrate the extract in the graduated Zymark tube to 1.5 mL.

2) Add 1.5 to 2.0 mL iso-octane and concentrate the extract again to 0.2 mL.