Procedures for Lab ware Clean-up
University of Vermont
*All lab ware we use is either Teflon or HDPE. The following clean-up procedures
are for use with these types of materials. HDPE should not be left in the
acid bath for extended periods of time.
Procedures for Lab ware Clean-up
University of Vermont
*All lab ware we use is either Teflon or HDPE. The following clean-up procedures are for use with these types of materials. HDPE should not be left in the acid bath for extended periods of time.
Laboratory Set-up:
20% Nitric Bath
A 30 L Teflon tub with lid and a Nalgene casing is filled with 20% HNO3 and resides inside a hood. A quartz heater is immersed in the acid to regulate temperatures from 20 - 70oC. The bath should be changed occasionally, but water may need to be added to replace that lost by evaporation from the 20% HNO3 solution.
Washing Bags
Draw string bags made from Teflon mesh and Teflon cord sit inside the Nitric bath. The draw strings loop onto a hook attached to the outside of the bath, so the bags can be easily reached. All lab ware should be placed in these bags so you do not have to reach into the acid to retrieve the lab ware.
5% Nitric Bath
A 10L Teflon tub filled with 5% HNO3 and covered with lid sits on a hotplate inside a hood. The hotplate is kept on "warm" when in use, which is about 38OC. The solution is changed after every 15-20 uses. Water may need to be added occasionally to replace that lost by evaporation.
Washing Procedures
Teflon beakers, lids, and watch glasses:
Before this step, all lab ware should have been rinsed to waste with 1% HNO3 and nanopure water as a part of the sample prep procedures. Dirty lab ware should be stored in a closed plastic container until its ready to be cleaned.
1) Place lab ware in Teflon washing bags. Make sure all beakers sink and are fully immersed in the bath. Pull draw string tight and loop end onto hook outside the bath. Close the lid to the tub and turn the temperature setting up to 7 or 8 so the bath will heat to about 700C. Leave the lab ware in the heated bath for at least 4 hours. Do not leave the heater on overnight. Because of its high chemical resistance, the Teflon lab ware can remain immersed in the bath indefinitely.
2) When you are ready to take the lab ware out of the bath, turn down the heater. If the bath is allowed to cool down for a couple of hours, at least, the acid will not react as quickly with the Neoprene glove material.
Pull the bag out of the bath, holding it suspended above the tub. Rotate the bag in all directions to drain acid from the beakers. Spray the bag with nanopure water and allow the rinsate to drain back into the 20% bath. Dump the contents of the bag into the clean HDPE basin. Return the empty bag to the 20% bath and close the lid. Rinse and hang up neoprene gloves, and change to clean disposable plastic gloves. Rinse the beakers in nanopure water. Place the beakers in the 5% HNO3 bath. Repeat this procedure with all lab ware in the wash bags. Set the hotplate to "warm" and leave contents overnight.
3) The next morning, remove contents of the 5% bath using Teflon tongs and place them in a clean plastic colander. Rinse the lab ware thoroughly with nanopure water over the hood sink. Put the lids on beakers and put them into storage containers to keep them clean. Place lab ware that will be used dry, in the clean oven.
Any lab ware made of HDPE (graduated cylinders, bottles, etc.)
Since HDPE is not as resistant to hot HNO3 as Teflon, this type of lab ware should be drenched with 1% HNO3 using a squirt bottle, or immersed in a tub of 1%, then rinsed thoroughly with nanopure water.
PROCEDURE FOR ACID CLEANING
NEW TEST TUBES AND PIPETTE TIPS
10/09/97
1. Rinse two 4 liter jugs and the white colander with clean 1% nitric from the squirt bottles, then rinse them with nanopure.
2. Fill one of the jugs with approximately 3 liters nanopure, then add 45 ml. concentrated HNO3 to make it 1%.
3. Using clean gloves, put pipette tips or plastic vials and lids in acid-filled jug, submerging them to ensure they are completely washed by the acid. Close lid tightly and shake jug several times.
4. Pour off the 1% nitric into the other clean 4 liter jug for reuse, being careful not to pour out the contents with the acid.
5. Pour the contents of the jug into the clean colander. Rinse well with nanopure, including the insides of the vials and pipette tips.
6. Dry overnight in the oven at 45-60 oC. Dry vials in styrofoam racks. Dry pipette tips and vial lids in acid-rinsed plastic trays.
7. When contents are dry, store in acid-cleaned, dry, covered containers.
NEW TAMPER CLEANING PROCEDURE
9/30/97
1. Put 50 or so NEW tampers in 500 ml Teflon beaker.
2. Rinse tampers in NANOPURE.
3. Cover tampers with 1% nitric acid and swish around for less than a minute. Do this in a hood.
4. Rinse nitric laden tampers 5 times with NANOPURE. Do this in a hood.
5. Drain NANOPURE.
6. Cover tampers with acetone and swish around for about a minute. Do this in a hood.
7. Drain acetone to acetone waste bottle.
8. Rinse tampers well with NANOPURE.
Place in oven to dry.
TARGET CLEANING PROCEDURE
9/30/97
1. Put 50 or so targets in 500 ml Teflon beaker.
2. Rinse targets in NANOPURE.
3. Cover targets with 1% nitric and sonicate 10 minutes in small ultrasound using beaker covered with watch glass. Do this in a hood.
4. Rinse nitric laden targets 5 times with NANOPURE. Do this in a hood. Fill beaker with NANOPURE and ultrasound for 10 minutes.
5. Drain NANOPURE.
6. Cover targets with acetone, cover beaker with watch glass. Ultrasound for 10 minutes. Do this in a hood.
7. Drain acetone to acetone waste bottle.
8. Rinse targets well with NANOPURE.
9. Place in oven to dry.
10. Seal in bag, put in acid washed box containing clean targets
Quartz Vial Cleaning
9/30/97
1. Count 100 vials into each of two 500 ml clean, flat bottom Savillex beakers.
2. Rinse the vials with copious amounts of NANOPURE WATER.
3. Wash the vials with 1% nitric acid, shaking vigorously
4. Rinse the vials several times to remove nitric acid
5. Place the beakers in the hood. Add sufficient 16% HF (2 times the volume of NANOPURE water to conc. HF ( ~120ml n.p. to ~60ml HF)) to cover the vials by a cm or two.
6. Place the beakers on the hotplate covered with a watch glass and turn hotplate full up. It will take around 30 minutes for HF to boil.
7. Boil 30 minutes.
8. Turn off hotplate and allow to beaker to cool. Drain acid to a waste bottle and rinse the beakers and vials several times shaking well to wash all vials. Do this in the hood.
9. Add sufficient 5% nitric acid to cover vials by 1 to 2 cm (~165ml n.p. to ~15ml HNO3).
10. Return beakers to hotplate and boil for 30 minutes.
11. Allow beakers to cool. Drain acid to waste.
12. RINSE VIALS SEVERAL TIMES IN NANOPURE, THEN RINSE EACH ONE INDIVIDUALLY and try to shake off all excess water.
13. Take half of the vials and repeat steps 5-12, but on step 7, boil for 15 MINUTES ONLY. These vials will be used for Beryllium.
14. Dry in clean oven. Place in washed ziplock bags in batches of 100. Label bags to indicate who cleaned the vials and when they were cleaned. Keep Beryllium vials separate and label bag with blue tape.
15. Place bags in acid washed storage box labeled clean vials. NOTE: Check all vials for holes in the bottom before using them. Discard any with holes.
FUNNEL CLEANING PROCEDURE
9/30/97
1. Fill 250 ml HDPE jar containing dirty funnels with nanopure water. Cap, shake, and drain to waste.
2. Add 1 ml detergent to jar, fill with nanopure, shake, and sonicate for 30 minutes.
3. Drain jar, and rinse funnels several times with nanopure, until suds are gone.
4. Cover funnels with 1% nitric acid and sonicate for 3 minutes. Do this in a hood.
5. Rinse nitric laden funnels 5 times with NANOPURE. Do this in a hood.
6. Refill jar with nanopure and sonicate for 10 minutes.
7. Rinse funnels twice more with nanopure, and drain.
Place in oven to dry.