Batch of samples undergoing a final etching

University of Vermont

10/27/97

PROCEDURE FOR FINAL ULTRASONIC QUARTZ CLEAN-UP

TO BE DONE UPSTAIRS

SAFETY PRECAUTIONS

Both concentrated HF and HNO3 are potentially dangerous acids. Under no circumstances should either acid be allowed to contact the skin, nor should the fumes be inhaled. These acids should be used ONLY in the fume hood and only if the user is wearing FULL protective clothing including eye protection.

1. ALWAYS WEAR GOGGLES WHEN HANDLING ACID

2. ALWAYS WEAR FULL RUBBER SMOCK, THICK NEOPRENE GLOVES, AND CLOSED TOED SHOES WHEN HANDLING EVEN DILUTE ACID.

3. BEWARE THAT LIDS MAY NOT SEAL TIGHTLY, LIFT BOTTLE BY BASE

4. NEVER WORK LATE AT NIGHT WHEN YOU WOULD BE ALONE.

5. RINSE ANY SPILLED OR SPLASHED ACID IMMEDIATELY WITH COPIOUS AMOUNT OF TAP WATER.

6. TIGHTLY CAP HF BOTTLE AFTER EVERY USE. DO NOT LEAVE UNCAPPED EVEN FOR A MOMENT.

****NOTE WELL!!! Ultrasound can not run more than 14 hours without being topped up with water. Always set the time to limit run time to no more than 14 hours. FAILURE TO DO THIS RESULTS IN REPAIR BILLS > $400 *****

PROCEDURE

Select a batch of 7 mineral tested samples that will be a batch. Place them together in a red tube rack

1. Add quartz from each tube to a different 180 ml Savillex beaker that has been Nitric washed. LABEL beaker and lid with sample name using tape. Do the same for all 7 beakers.

2. Rinse out quartz tubes with 1% HNO3 and then NANOPURE water. Place in the upstairs oven in green rack to dry.

3. Fill beakers with DEIONIZED water until quartz is just covered.

4. Put one beaker at a time in the hood. Add 10 ml HF and 5 ml HNO3. CAP TIGHTLY. Place on ultrasound in lab.

5. Fill ultrasound to within one half inch of top with DI water.

6. Turn on heat, ultrasound, and timer. Let run at 6 to 8 hours. Any longer run than this may cause precipitation of amorphous silica on beaker lids.

7. Drain acid into waste container in hood.

8. Rinse beaker and quartz at least four times with NANOPURE water at >17 Mohms. USE CLEAN GLOVES FOR THIS. Do this in the washing hood and drain into sink. Put beaker with quartz in oven to dry. Drying will take > 12 hours. As soon as quartz is dry, transfer back to 50 ml tube along with label. Set tubes in green rack and put on shelf above balance.

9. Rinse beakers in NANOPURE to remove any quartz. Soak beakers and in 20% nitric bath, rinse, soak in 5% nitric bath, rinse, and put away wet.