Chromatography Forum

Hi all,

I have a need to determine the level of TBAC in a material.

For an ion pairing agent the compound seems well retained on a C18 column (standard ACN:Water 0.03%TFA) and is easily detected by LCMS (obviously as the quat ammonium ion).

However, the RSD for 6 replicate injection is ~20% and the Linearity has an R2 = 0.8164. A spiked sample recovered only ~70% of the TBAC.

I've also tried it under 0.1% formic acid conditions but observed the same results.

This instrument produces acceptable results for other compounds - so any idea as to the reason for this compound specific variability?

Many thanks in advance,

Serp.

Hi all,

I have a need to determine the level of TBAC in a material.

For an ion pairing agent the compound seems well retained on a C18 column (standard ACN:Water 0.03%TFA) and is easily detected by LCMS (obviously as the quat ammonium ion).

However, the RSD for 6 replicate injection is ~20% and the Linearity has an R2 = 0.8164. A spiked sample recovered only ~70% of the TBAC.

I've also tried it under 0.1% formic acid conditions but observed the same results.

This instrument produces acceptable results for other compounds - so any idea as to the reason for this compound specific variability?

Many thanks in advance,

Serp.

Given the immense difficulty in completely removing an IP reagent from a C18 column which has been used in IP chromatography, I am not surprised at you results.


Have you tried using less non-polar stationary phases, they may improve your results.

HILIC column may work better