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  1. Place ~2 cm3 (or 5 mL) of undried (preferred) sample into a centrifuge tube (Figure XX).
  2. Add ~25 mL of 10 % Acetic Acid (Figure XX).
  3. Mix and shake well (Figure XX). Let sit for at least 1 hour to decarbonate (until the reaction ceases). Close the centrifuge tube with its cap but not too tight to avoid unnecessary overpressure.
  4. It helps to place the centrifuge tubes on the shaker in the cold room of the Chemistry Lab (Figure XX). Do not tight the tube too strong in the arm as it can break while vibrating. Set a shaking time of about 30 seconds (it is a good start) and a power value of 1. After using the shaker, shake the tube to ensure the reaction has stopped (i.e., no more bubbles).
    Note: Please note that sample with a large amount of carbonate (more than 50%) may require more than 1 treatment of Acetic Acid to reach complete decarbonation.
  5. Next step is to spin the sample in the centrifuge. Make sure to choose the correct tube holders. It is very important to balance the centrifuge, and to evenly distribute weight. Put samples symmetrically opposite.  If you run a odd number of samples, keep the balance by filing up an additional centrifuge tube with DI to have an even number of tubes in the centrifuge. Turn on the centrifuge in the Chemistry Lab (Figure XXA). Press the "Speed" button (Figure XXB) and select a speed of 1500 rpm (rotation per min) by using the arrows to increase or decrease the value (Figure XXD). Press the "Time" button and select a time of 15 min by using the arrows to increase or decrease the value (Figure XXC). Press the "Start" button to start the centrifuge (Figure XXE).
  6. Decant the acetic acid solution and dispose of the acid solution properly in an appropriate sink (Figure XX).
  7. Add 25 mL of DI (nanopure water) to the centrifuge tube (Figure XX). Shake to get rid of the acetic acid. Centrifuge again for 15 min at 1500 rpm. 
  8. Decant the clear water. Repeat the "wash cycle" (i.e., centrifugation) with DI. Wash at least 3 times to remove all Acetic Acid (until it does not smell vinegar too strong).

Figure XX. Decarbonation with acid acetic.

Figure XX. Using the shaker to help decarbonation reaction.


Figure XX. Setting the centrifuge.

Figure XX. Disposal of acid solution and DI washing cycle.

Hydrochloric Acid Treatment

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