USGS

U.S. Geological Survey Open-File Report 01-257

By Kinga M. Revesz, Jurate M. Landwehr, and Jerry Keybl


APPENDIX A: COMPLETE STEP BY STEP PROCEDURE

Weighing and Storing Samples:
  1. Samples should be dried overnight in a 90ºC oven and kept in sealed vessels.
  2. Condition balance (this step should be done once a day):
    a. Place empty aluminum boat on balance and close door. Wait for reading to stabilize (the 'g' on the display appears). Tare the balance.
    b. Remove and replace boat and make sure the stabilized weight is 0.000 mg.
    c. Repeat these steps until the balance is stable.
  3. Remove boat from balance, add sample and weigh the filled boat. Repeat until you have 400±20 µg.
  4. Quantitatively transfer sample into a dried sample vessel and seal.
  5. Mark sample ID and weight on the side of the vessel with a permanent marker.
  6. Weigh boat again. It should read 0.000 mg. If it doesn't, there is a problem with the way in which the sample was weighed or transferred.
  7. Repeat steps 2-5 for every sample.

Note:

  1. Do not cross contaminate samples:
  2. a. Make sure aluminum boat always weighs 0.000 mg when empty.
    b. Make sure the spatula and sample area are cleaned using chem wipes.
  3. Always allow balance to stabilize before removing boat.
  4. Use the same boat until it becomes unusable.

Washing Sample Vessels:

  1. Remove marker with chem wipe and Propanol (isopropyl alcohol).
  2. Remove and dispose of the caps; place vessels in tray.
  3. Rinse set of vessels 8 times with tap water and once with de-ionized (DI) water. Use mesh to hold vessels in place when emptying them.
  4. Fill ultrasound with DI water. Place the vessels in the DI water.
  5. Ultrasound the vessels for 30 minutes.
  6. Remove the vessels and empty the water out of them. Place the vessels in a tray.
  7. Dry vessels in a 90ºC oven for at least 24 hours.
  8. Check the seals on the new caps and lay them out to cover the dried vessels with.
  9. Remove vessels one by one from oven; cap dried vessels immediately to keep out moisture.

Loading Samples in Tray:

  1. The needle assembly (sampling arm) must be moved out of the way by the GasBench II controller located on the left side of arm.
  2. At job queue screen, press F1 (MENU).
  3. Turn knob until SETUP is highlighted. Press 'Enter' (button is located inside the knob).
  4. Turn knob until OBJECTS is highlighted. Press 'Enter.'
  5. Turn knob until TRAYS is highlighted. Press 'Enter.'
  6. Turn knob until 2ml-I is highlighted. Press 'Enter.'
  7. Turn knob until OFFSET X (-44.2mm) is highlighted. Press 'Enter.'
  8. Remove sample bath cover.
  9. Load samples using the left upper port as 1. Note port, sample ID, and weight as the samples are entered. The sequence is loaded left to right, top to bottom.
  10. Place vessels containing 100% pure phosphoric acid (H3PO4) into the last 3 ports.
  11. Replace bath cover. (Make sure the hole for the cable is located on the backside of the cover.)
  12. Press F4 (HOME) to return the sampling arm to its normal position.

Flush Samples:

  1. Make sure that the flushing needle is in the GasBench II sampling arm.
  2. Open the valve of the flushing helium tank. Check the flow of the GasBench II regulator marked "Ref 3." It should be set at 21 psi.
  3. ISODAT Settings:
    a. Select GASBENCH from CONFIG column.
    b. Select "A-CON-B" from ENVIR. Column
    c. Select "2. SEQUENCE ACQ." (If the option is not visible, hit ALT-T.)
    d. Make sure TABLE NAME value is highlighted.
    e. Select TABLE DIR from status bar at bottom of screen.
    f. Select FLUSH from options and right-click it.
    g. Check to make sure START LINE and END LINE match what samples you have loaded.
    h. Click SAVE from status bar.
    i. Click MEASURE from status bar to begin flushing.

Add Sample Information to Queue:

  1. Select GASBENCH from CONFIG column.
  2. Select EDIT-B from ENVIR. Column.
  3. Select 2. SEQUENCE EDITOR. If you do not see it, hit ALT-T.
  4. Select CACO3.
  5. Click EDIT from status bar.
  6. Enter GasBench II Port # / GasBench II Method #
  7. Enter Sample ID in SAMPLE IDENT field. Enter must be hit after every change in order for ISODAT to accept it.
  8. Enter process File.
  9. Enter the mass into the SAMPLE SIZE field.
  10. Add any comments concerning the sample that you may have.
  11. Click NEXT LINE from status bar for the next sample.
  12. Repeat steps 6-9 for every sample.
  13. When finished, click EXIT/SAVE from status bar.

Note:
The EDIT MASK and COPY MASK commands can be used to avoid typing repetitive data.

Add Acid:

  1. Move sample arm out of the way (see Loading Samples in Tray, steps 2-7).
  2. Place the gas tight syringe into the acid and suck up 0.1 ml of acid.
  3. Remove the syringe from the acid and wipe the extra acid of the tip with a chem wipe.
  4. Punch the syringe into the rubber septum of the sample vessels. Hold the plunger in place. It is best to punch the septum off center.
  5. Expel the acid and wait 30 seconds to make sure that no acid remains on the needle. Remove the syringe.
  6. Repeat steps 2-5 for each sample vessel in the set.
  7. Press F4 (HOME) to return the sampling arm to its normal position.
  8. Wait 24 hours before running the samples.

Run Samples:

  1. Select GASBENCH from CONFIG column.
  2. Select ACON-B from ENVIR. Column.
  3. Select "2. SEQUENCE ACQ." If this option is not visible, hit ALT-T.
  4. Make sure the TABLE NAME field is highlighted. Select TABLE DIR from status bar.
  5. Select CACO3 and right click on it.
  6. Change START LINE and END LINE to correspond to what samples will be run.
  7. Select SAVE from the status bar.
  8. Select MEASURE from the status bar.

Retrieve Data from ISODAT:

  1. Select GASBENCH and EVAL-B from the CONIG AND ENVIR. Columns.
  2. Select "1. OFFLINE EVALUATION." If this option is not visible, hit ALT-T.
  3. Select Sort Index (default is Spec #).
  4. Choose DIRECTORY from the status bar.
  5. Tag all the runs using the TAG ALL command and parenthesis.
  6. Select ONL-EDIT from the Screen. Column.
  7. Page down to the fourth page.
  8. Enter "NO" in the LIST TYPE field.
  9. Enter "ALL" in the PEAK REPORT field.
  10. Enter "a:\mmddyy.wks" in the FILE NAME field.
  11. Enter "FORMAT1" in the LIST TYPE field.
  12. Enter "LOT" in the FILETYPE field.
  13. Choose EVAL.
  14. When the exporting process is complete, choose EXIT.

Store Data in LIMS:

  1. Open file in Excel. (*.wks file from floppy)
  2. Select filter from the data menu. Filter runs 1, 2, 3, 11, 12, and 13.
  3. Fill the R column with asterisks, once the runs are filtered.
  4. Save the modified file.
  5. Start LIMS.
  6. Choose "Import Analysis."
  7. Choose Mass Spec Delta-XL.
  8. Click Import.
  9. Select the file that will be imported.
  10. Select columns F30 and F31. Check the boxes to import these two columns.
  11. Click Import.


Continue to Appendix B: ISODAT "CAC03" Method , or return to Table of Contents



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