[dm1217]

Please let me know if this is a good/bad method-

I use a micro liter syringe to inject samples into a gas chromatograph. After injecting, I flush the syringe with acetone 2-3 times  (draw it up, and shoot into flush container.)  When its time for a new sample, I flush out the syringe about 8 times with the new product.  (When I flushed it less times, I was getting a lot of contaminated GC readings, or commonly acetone spikes.)

Hopefully theres a more efficient way of keeping the syringe clean, while eliminating sample contamination?  (This is usually a repetitive part of my job.)

I've also had a problem with black buildup in the syringe. Eventually have to toss them in the can.

All comments will be appreciated 

[nj_bartel]

Someone can probably give a much better answer than this, but it depends a lot on what it is you're putting in the syringe.

[Borek]

What solvent is your sample dissolved in? Use it (instead of acetone) to flush the syringe, there will be no problem with acetone contamination.

[enahs]

Try other solvents. I use methanol for our syringe all the time for when we do direct injection to a mass spec.

Also, after you clean the syringe, take the plunger out and needle off if it is removable. This will allow for the small amounts of cleaning solution left in the device to evaporate. Also make sure to clean the outside of the syringe needle as well. And also clean off the back side of the plunger once also (the side behind the seal that goes into the glass housing).

[dm1217]

Methanol might be better than acetone for syringe cleaning?

I have been using methanol to clean a syringe before a standard reagent moisture test (and acetone before a ketone reagent test)

Much of the system here is carried over from the previous lab tech,  and so now i'm trying to get the system "down to a science"

[enahs]

Methanol might be better than acetone for syringe cleaning?

It all depends on what you are cleaning. The key is to just rinse it well, and let the solvent evaporate out before use.

Another alternative, and a good idea. Say the solution you are injecting is in acetonitrile, well, then flush the syringe out after cleaning once with acetonitrile.

[P]

Also you could rinse more than the 2 or 3 times  -  try 5 or 6, then a couple of times with the new product. The acetone must be fairly cheap in microlitre amounts.