Chromatography Forum

Hi everyone,


We think we are seeing increase matrix effect on injected samples over time (years).

Standards injections look ok though.

Any ideia what specific part could be replaced / cleaned in the LC-MS/MS to overcome this?


Thank you all for your time and help.

Maybe your matrix changes over the years?
Matrix effects originate from co-eluting substances which facilitate or quench the ionisation process of your target molecule.
I my be wrong, but I think as long as your standard performs as expected, replacement or cleaning of hardware is not required.

Maybe your matrix changes over the years?
Matrix effects originate from co-eluting substances which facilitate or quench the ionization process of your target molecule.
I my be wrong, but I think as long as your standard performs as expected, replacement or cleaning of hardware is not required.

Thank you very much for your time and reply, bunnahabhain.

We have liver and urine samples, so.. matrix changes over the years is not impossible (feeding products and protocols in the market do change over time) but we do not believe it to be the most likely source of the problem.

We have seen, since equipment was new, a slow change into less sensitivity / greater matrix effect in injections.

We strongly believe there is equipment parts erosion behind this effect, but we battle about what it might be.

Any thoughts?

Thanks

Do you perform routine preventative maintenance and cleaning on a regular basis?

Also, what model is the instrument you are using? Different instruments have different parts that can cause such a problem.