HI, I"m working primarily with octanols and derivatives of them. I am having problems cleaning my syringe out. I have been basically rinsing with water a lot but the inside of the syringes keep turning yellow and that makes it impossible to read. I was wondering if anyone had any suggestions on cleaning or what might be causing me these problems.

We use a commericial syringe cleaning soap--i forget offhand who manufactures it, but it does a good job for us.

Dear christina :

It will not be possible to clean out a syringe used for octanols with water.

I suggest you remove the syringe plunger and sonicate the syringe barrel and plunger separately
in a non-polar organic solvent like benzene or cyclohexane. Keep an eye on the temperature and don't sonicate for more than ten minutes at a time. Try to use a removable needle syringe since the fixed needle types use an adhesive which might dissolve in the sonicating solvent.

Also, Hamilton and Supelco offer a good syringe cleaning device which simply heats the syringe needle to red-heat. This is perhaps the best way to clean out the needle.

Hope this works. Do let me know whether it does.

Rgds.
srinivas

Christina,

Have you tried to use a syringe with a Teflon-tipped plunger? They are available from several manufacturers.

Joh

rinse well with acetone (it is a good all-purpose, ater soluble solvent of intermediate polarity--it should remove octanol). Then soak in a cleaning mixture--the commercial cleaner seems to be a mixture of nitric and acetic acids with a *small* amount of good lab soap (e.g alconox). Acid percentages are small, eg. 5%. To avoid cleaning, regularly rinse the syringe with acetone, and then with at least three volumes of water to prevent carry-over into your samples. Good luck to you.