Chromatography Forum

Hi all I have been having trouble recently with raw materials getting onto the syringe and seemingly finding some nook to hide somewhere and being very hard to clean. I have the 10ul syringe with the screw on needle. After each run I normally rinse 5X with acetone and 2X methanol and hexanes if that is the injection solvent. I acutally took the syringe off and sonicated it in isopropanol and there is still some caryophyllene on one syringe and sulfuryl acetate and sulfurol on the other.

Any suggestions?

Finding what those are soluble in is quite a chore, easy to find not soluble in water, but finally found that all are listed as soluble in alcohol, which usually means ethanol.

Maybe Acetone is not the best choice for first solvent. Try using Ethanol or Methanol first and see if that helps. You may also try Methylene Chloride if you are not using an ECD.

Rig up a vacuum with a septum inlet, stick the syringe needle through, pull the plunger out of the body and rinse the body with plenty of a range of solvents. Then wipe down the plunger with tissue wetted with the same solvents. Hamilton used to sell a syringe cleaner with a septum and vacuum connection.

Peter

Pretty much everything I work with is soluble in acetone which is why I often use it. I don't like using chlorinated solvents in my rinse vials as it is partially open and evaporates into the air and I'd rather breathe in acetone than MeCl2. I can try ethanol though it has less nonpolar dissolving capabilities than acetone.

Rig up a vacuum with a septum inlet, stick the syringe needle through, pull the plunger out of the body and rinse the body with plenty of a range of solvents. Then wipe down the plunger with tissue wetted with the same solvents. Hamilton used to sell a syringe cleaner with a septum and vacuum connection.

Peter

A trick I learned when I first began doing GC work was a reverse to this. Take an autosampler vial filled with the rinse solvent, remove the plunger from the syringe, insert the needle into the vial, then hold the vial to the injection port top. The heat will force the solvent up and out the top of the syringe. Place a tissue at the top to keep the solvent from spilling on everything. With low boiling point solvents like hexane you will empty the vial in a couple of minutes, flushing a 10ul syringe with over a 1ml of solvent quickly.

Rig up a vacuum with a septum inlet, stick the syringe needle through, pull the plunger out of the body and rinse the body with plenty of a range of solvents. Then wipe down the plunger with tissue wetted with the same solvents. Hamilton used to sell a syringe cleaner with a septum and vacuum connection.

Peter

A trick I learned when I first began doing GC work was a reverse to this. Take an autosampler vial filled with the rinse solvent, remove the plunger from the syringe, insert the needle into the vial, then hold the vial to the injection port top. The heat will force the solvent up and out the top of the syringe. Place a tissue at the top to keep the solvent from spilling on everything. With low boiling point solvents like hexane you will empty the vial in a couple of minutes, flushing a 10ul syringe with over a 1ml of solvent quickly.

I like it

Peter