I will be working on a method that specifies a sample injection volume of 100ul, my agilent 1100 system has a default syringe size of 100ul (250ul loop size). I was talking to the analyst who was running this method before, I was told that sometimes OOS results (for example, low assay value) were generated from sample injector malfunction (also done on Agilent 1100), but if the same vial was injected again, the result was fine. I can not change the method, since it is already finalized. I would like to find out if anybody has had experience or has encountered problems injecting at full syringe volume of sample and if so, what are your opinions and/or suggetions. Thank you in advance!

I have not worked with the 1100 but can you get a larger syringe for it? Most likely the problems you are getting are due to air getting in the syringe. Be sure to degass everything as well as possible also see if you can slow down the sample speed. The syringe may degas the sample if it pulls to fast causing a bubble.

Thank you for your advice. The next syringe size is 900 microliter, I think it might be too big. I will look into slowing down the drawing speed. Thanks again.

I would think that a 900 mcl syringe would work. Typically a 10 mcl injection is made using the 100 mcl syringe. A 100 mcl from a 900 mcl syringe is really no different.