Archaeological Sample Prep for San Elijo
Melissa Trout
May 11, 2002

1. Rinse cut off bottles (numbered 1-12) w/ dH₂O to clean
   
   
2. Fill with 15 mL of 10% HCl (can do by eye or measure)
   
   
3. Put 1,3,5, or 15 cc spoon size of sample from bag into HCl (if syrupy add more HCl)
   
   
4. Add 1 tracer to each and allow time to dissolve
   
   
5. Make sure large screens are clean
   
   
6. Rinse side with dH₂O from squirt bottle, wait 5 seconds, pour until level with test tube holder onto screen over funnel into plastic test tubes (with same sample number)
   
   
7. Balance opposite tubes
   
   
8. Centrifuge for 3-4 minutes
   
   
9. Decant, wash out bottles and allow mud to dry out in large beaker (avoid putting sediment down the drain)
   
   
10. Add HF slowly in fume hood (make sure to wear goggles, face mask, shoes, pants, apron) with test tube in ice and water. First, add until level with edge of test tube holder and see if sample is reacting. Slowly, add until more than half full.
    
    
11. Cover with saran wrap and fasten with rubber band and identify as containing HF. Let sit overnight.

After HF Overnight

1. Set up spare rack of large tubes behind the samples with wooden stirrers
   
   
2. (Wear face mask when rinsing HF) Remove saran wrap from sample, make tubes level by adding dH₂O, centrifuge for 4 minutes.
   
   
3. Decant into waste container, stir, add dH₂O (until level about 1” from top of tube) and stir more
   
   
4. Centrifuge 4 minutes, decant into waste container, stir
   
   
5. Add ¾” of concentrated HCl (count to 3 while pouring) then add dH₂O to rest of tube
   
   
6. Centrifuge, decant into waste
   
   
7. Transfer samples to little tubes (marked with same sample numbers) in blue racks using as little dH₂O as possible. If you can’t get all the material into one tube, get into 2, centrifuge, decant, and condense into one tube.
   
   
8. Level tubes with dH₂O
   
   
9. Centrifuge 4 minutes, decant, stir well (if you see a layer of lighter silicates here add more HCl and centrifuge, then rinse with dH₂O and centrifuge)
   
   
10. Set up the hot water bath (with tap water) on hot plate on continuous heating. Put squirter bottle of 10% KOH and bottle of dH₂O in the water bath. MAKE SURE TO LOOSEN THE TOPS OF THESE BOTTLES WHILE IN THE BATH and tighten when pouring
    
    
11. Pour 120 mL of acetic acid into a beaker.
    
    
12. Pipet 4.7 mL of acetic acid into each tube and stir (do not add dH₂O)
    
    
13. Centrifuge 4 minutes, decant into waste cup but do not dispose of until acetolysis is complete, stir
    
    
14. Add 5 mL acetic anhydride (push liquid up past line in neck of bottle, and 5 mL will dispense automatically)
    
    
15. Stir, remove stir rod
    
    
16. Point tube away from body and pipet 0.55 mL of H2SO4 into samples with acetic anhydride still in them – do NOT stir now. Be cautious - if water is left in the sample there could be an explosive reaction.
    
    
17. Centrifuge 4 minutes, decant into cup
    
    
18. Add 4.7 mL acetic acid (again) and stir
    
    
19. Centrifuge 4 minutes, decant into cup, dispose of material into waste container
    
    
20. Add KOH (use hotmits and remember to tighten top) up to fill line, stir
    
    
21. Centrifuge 4 minutes, decant into waste
    
    
22. Add hot dH₂O (remember to tighten top) and stir
    
    
23. Centrifuge 4 minutes, decant into waste
    
    
24. Repeat water rinses until clear (at least 3 times)
    
    
25. NYTEX IF NECESSARY (to nytex get white nytex screen, and cut off urine sample cup and make a sieve. Wash sample into sieve using dH₂O and add dH₂O + soap already in squirter bottle to break up material. Wash through sieve repeatedly with dH₂O from squirter bottle. Set down on a paper towel and see if water on towel is clear – if dark run through more water. Use a funnel to wash back into previous tube. Centrifuge, decant and continue on with next step.
    
    
26. Transfer to 4 mL vials using touchplate to get all sediment out of tubes
    
    
27. Add 3-5 drops of dye (not the stronger dye)
    
    
28. Centrifuge 10 minutes
    
    
29. Get out remaining water using disposable pipets and red bulb. (Press below the bulb to suck water up and to dispense press to side of bulb. If bulb gets full of air press above bulb)
    
    
30. Add 3-5 drops glycerine from squirter bottle
    
    
31. Place in dessicator. Stop air, turn red valve, wait for top to open.
    
    
32. Leave for a few days, checking to make sure samples don’t dry out. If necessary add more glycerine.