Cleaning the Syringe

[Kaliane]

Hello,

How do you choose the solvent/product to clean the syringe?

I have a problem with the cleaning of the syringe. I use the analysis' solvent to clean the syringe (ethanol, in my case), but the syringe turn color to yelow and black after some time, as you can see. The biggest problem is because, besides changes colors, the syringe clogs, and, consequently, brokes.

How can I solve that problem?

My syringe is Hamilton 80300 701N 10µL (26s/2”/2)

PS: My samples are wine, whisky or juice. The samples are always distilatted.

[James_Ball]

Are these injections done by hand or by autosampler?

The metal plunger tip syringes do not make a perfect seal (very good but not perfect) between plunger and inside of the barrel, so there will be some sample that moves up the barrel beside the plunger. If manual injections, wash by taking the plunger to at least 10ul or a little over and wash 5-6 times that way. At least once per day I would remove the plunger and wipe it carefully with a tissue soaked in solvent to help keep it clean. You may also want to try different solvents such as water, methanol or even stronger solvents, to remove anything that is not completely soluble in the ethanol.

[larkl]

Some labs use something like this. It heats the syringe slightly and can be attached to vacuum. You can pull the piston and squirt a bit of solvent through it.

https://www.analytics-shop.com/us/ht766 ... 4SEALw_wcB

Other labs just use a filtering flask with a syringe port (put a septa in a 1/4" swagelok fitting) and jam that in the hole in a rubber stopper. Hook the flask to vacuum. Insert the syringe, pull the piston and squirt some solvent through it.

I've used acetone almost exclusively for decades for syringe cleaning.

[James_Ball]

Some labs use something like this. It heats the syringe slightly and can be attached to vacuum. You can pull the piston and squirt a bit of solvent through it.

https://www.analytics-shop.com/us/ht766 ... 4SEALw_wcB

Other labs just use a filtering flask with a syringe port (put a septa in a 1/4" swagelok fitting) and jam that in the hole in a rubber stopper. Hook the flask to vacuum. Insert the syringe, pull the piston and squirt some solvent through it.

I've used acetone almost exclusively for decades for syringe cleaning.

Another quick trick similar to this is to fill an autosampler vial with acetone, insert the syringe and remove the plunger, then hold the vial near the septum nut on the inlet for a gently heat, it will expand the acetone and force it up through the syringe.

[MSCHemist]

I use toluene as my A rinse and sample solvent as my B rinse (unless it is MeCl2 I don't like having that floating arround the lab I sub something else in that case).

Toluene dissolves almost anything and it has a higher boiling point so it tends to have more time to rinse out analytes. I had a seminar on this topic a while back and they recommended using a higher boiling solvent for A to help prevent gummy plunger issues. The trade of is a substantial peak will often show up in the chromatogram.