Chromatography Forum

Hello to all,
Im working in an analysis of a cation and I have problem with the repeatability of the peak area of my analyte between a series of injections.
Im using a system with an IC detector, chemical suppressor and an HPLC waters. I know that in IC needed a full plastic system. The HPLC part in my system contains stain steel parts which cannot be replaced with plastic ones.
Is there any possibility the stain steel parts be the cause of the peak area variability?

Thanx in advance

Is there any possibility the stain steel parts be the cause of the peak area variability

*Anything* is possible, but unless you tell us what the analyte/mobile phase/column are, there is no way to say any more.

Well, the analyte is the choline cation, the mobile phase is methanesulphonic acid (6mM) and im using the column IonPac CS19 with a relevant guard.

Those should be compatible with stainless steel.

I would recommend to have a metal free system when working with MSA as an eluent.

Could the problem be that you're using plastic syringes and filters for your final sample prep step and introducing semi-random amounts of chloride?

Is there a pattern to the variations in area? If areas are generally drifting up or down, you might have to consider chilling your samples as they may not be stable.