samples waiting to be tested....

University of Vermont

10/15/97

PROCEDURE FOR TESTING QUARTZ PURITY -- MINERAL TESTING

TO BE DONE UPSTAIRS

HF is a potentially dangerous acids. Under no circumstances should acid be allowed to contact the skin, nor should the fumes be inhaled. Acid 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.

PROCEDURE

From the drawer labeled to be mineral tested, upstairs, select a batch of samples to test for which there is >25 grams of clean quartz with no visible mafics. Clean the quartz with magnet. If mafics remain, do an additional mineral separation and one-step ultrasonic etching BEFORE MINERAL TESTING.

1. Label as many small Teflon beakers as there are samples to test (we have 30 Savillex with lids)

2. For each sample, tare the beaker. Add about 0.5 grams of quartz to the beaker. RECORD QUARTZ WEIGHT ON MINERAL TEST DATA SHEET. Place all beakers in hood. Add ABOUT 5 ml of HF. Place on the hot plate with a closed lid at subboiling (setting 225) for 4 to 8 hours or until the samples are dissolved.

3. When samples are dissolved, remove lids and dry off HF. Dry off uncapped at 300 for about 4 hours. Set the lids next to the samples in order.

4. Take samples off hotplate and allow samples to cool. Arrange samples in the order that samples are entered on the spread sheet.

5. Move the balance into the hood. Tare the balance with beaker in place.

6. Use Eppendorf or repipettor to add about 7 ml of 1.2 N HCl to the sample. Weigh the beaker with acid and record the total weight on MINERAL TEST DATA SHEET.

7. Swirl and if necessary use a disposable pipette to redisolve the sample. Put capped beaker back on hotplate at 225 to redisolve. 10 minutes should be plenty.

8. COOL Beakers. In the HOOD and in order of the test sheet, transfer the sample to a 15 ml test tube (UNWASHED AND WITH A PURPLE CAP), and pull label off beaker and use to label tube.

9. Run samples on ICP and enter data on mineral test sheet.

10. Print two copies of mineral test sheet. Place one in designated note book; take the other and cut out the section with the sample, Al, Fe, Ti and Ca. Cut this into strips for each samples and tape each to the quartz tube that it represents.

11. Samples with Al, Fe or Ti over 150 ppm may need more cleaning and should be called out.