USGS Open-File Report 02-371, Geochemical Sediment Analysis Procedures, Gamma Aliquots

PLANAR GAMMA ALIQUOT
Materials Required: 2 Decimal Place Balance Titanium Spatula Dried Sample New Aliquot Container (acid-washed Planar-type) Lab Notebook (not pictured)
Label the jar and the lid. Weigh the empty, acid-washed, Planar-type container (with the cap on) and write the weight on the container. Tare the balance with the empty container without the cap.
Transfer the sediment to the gamma jar using a clean, acid-washed titantium spatula. Weigh the sediment - should be between 4 and 50mm in height (measure with ruler or pre-marked vial). Write the sediment weight and height on the container and the cap. Enter weights into lab notebook - these weights will be transferred to an electronic format.

WELL GAMMA ALIQUOT
Materials Required: 2 Decimal Place Balance Titanium Spatula Samples New Aliquot Container (glass, acid-washed Well-type) Tamping Tool (not pictured) Aliquot with water to compare heights (11mm)
Weigh the empty container with the cap on and write the weight on the container. Tare the balance with the empty container (no cap). Add a small amount of sediment to the vial using a small, acid-washed, titanium spatula.
After a few spatulas of sediment are added, tamp down the sediment until no pore spaces are visible.
Repeat adding and tamping sediment until level with the water filled vial (11mm of sediment) which is equivalent to the depth of the sample well on the detector. Weigh the sediment and record weight and height on the vial as well as in a lab notebook.

Geochemical Sediment Analysis Procedures, Open-File Report 02-371