A glove box is an important device used in research laboratories and industry to work with air- and water sensitive compounds, and radioactive and biohazardous materials.
A glove box provides an isolated and enclosed environment with an inert atmosphere.
The gloves are used to work with the chemicals and instruments inside the box allowing for handling of very sensitive materials, which is not always possible with a Schlenk line.
This video will illustrate how a glove box works and how to safely manage the use of chemicals, solvents, and waste inside the box.
The inert atmosphere inside a glove box is established by a closed circulating system using a blower, pluming, and a gas purification system. The purifier ensures that the water and oxygen levels are kept below 1 ppm by circulating the atmosphere. The copper containing catalyst present in the purifier converts oxygen to copper oxide. While molecular sieves are used to absorb and remove the water molecules.
Furthermore, vacuum pumps and inert gas ensure that no contamination is introduced when passing chemicals or instruments through the antechamber into the glove box.
To introduce materials and objects into the glove box, first check if both doors of the antechamber are closed. Fill the chamber with nitrogen by turning the valve to fill, if the chamber is initially under vacuum.
Open the outer door, and transfer the desired object in the chamber, making sure to slide the tray as deep as possible to facilitate easier reach from the inside of the glove box. Then close the outer antechamber door carefully and turn the valve to evacuate.
Wait until the pressure reaches an acceptable vacuum level and then turn the valve to refill, so the chamber will be purged with nitrogen to normal atmospheric pressure.
Wear cotton or nitrile gloves and enter the gloves of the glove box slowly. Be careful when inserting hands into the gloves, because a too sudden movement can cause a rapid pressure change leading to air leakage from outside inside the box through any micro pores. Also, wear nitrile gloves over the glove box gloves to protect them against solvents and chemicals.
Now open the inner door to the glove box and remove the objects from the antechamber and place them in a safe location in the glove box, then promptly close the door.
With both doors closed, turn the valve to vacuum, which is the default position of the antechamber when not in use.
Label and store any synthesized chemicals in an appropriate location within the glove box. Remove any other objects as soon as you are done and clean the area.
Always make sure that all chemicals and containers are properly sealed before the transfer. Make sure the antechamber is filled with nitrogen before ejecting your materials. If you are unsure, repeat the evacuation-purging cycle three times.
Open the inner door, place the objects inside the antechamber, and close the door. Then, open the outer door and remove your objects. Close the door and turn the valve to evacuate and leave it at this default condition.
Maintaining the glove box's inert atmosphere is essential for a safe working environment. Therefore special handling of chemicals, solvents, and equipment has to be assured.
Make sure to always transfer only dry objects and reagents into the glove box to maintain the inert atmosphere and low levels of oxygen and water.
Chemicals, including solvents, have to be dry and deoxygenated. Use a new bottle of the desired chemical to avoid chemicals containing a higher amount of contaminants absorbed from the air.
Certain volatile chemicals such as thiols, amines, or halogens can poison the catalyst making it less efficient. Therefore use a Schlenk line for compounds like these, if possible. Shut off the blower, if a glove box has to be used, to minimize catalyst poisoning.
Furthermore, avoid introducing aqueous solutions and alcohols into the glove box to maintain low levels of water and oxygen.
Use only the required amount of reagents and never transfer full reagent bottles into the glove box, unless these reagents will be permanently stored in the box. Vials can be used for the transfer of solids and non-volatile liquids inside the glove box.
All reagents need to undergo the evacuation-purging cycle, therefore wrap the top of the vials with lab wipes and secure with a rubber band.
Additionally, glass vessels need to be evacuated before insertion into the antechamber to prevent explosions due to the pressure difference. And sharp objects such as needles and razor blades should be handled with extra care to avoid puncturing the gloves of the glove box.
Once in the glove box, solvent and chemical bottles should always be capped and placed back in the appropriate location for storage. Spills must be promptly wiped off and absorbents such as lab wipes removed to avoid damage to the gloves from vapors.
Properly label all designated waste containers inside the glove box. Liquid waste bottles must be capped at all times and needles recapped after use before disposing of them, and in case of a spill any clean up material should be disposed in the solid waste.
If the waste container is full, transfer it out of the glove box and dispose of the waste appropriately in the laboratory waste. Replace the waste container in the glove box promptly.
Maintenance should be performed to ensure longevity of the glove box. Regularly change the vacuum pump oil, 5% hydrogen in nitrogen and heating to reduce the formed copper oxide.
Furthermore, make sure the chambers are always left under vacuum.
You've just watched JoVE's introduction to working with a glove box. You should now understand how a glove box operates, how to safely transfer objects inside and outside the box, and how to handle chemicals, solvents, and waste. Thanks for watching!