AssayIndex
Chromatography

Trifluoroacetic acid (TFA)

Mobile-phase additive at 0.1 %. Gives excellent peptide peak shape and suppresses electrospray ionisation. Also the most common peptide counter-ion.

Related terms

Counter-ion
The anion paired with a peptide's basic residues in the isolated salt. Usually trifluoroacetate or acetate. Mass in the vial that is not peptide.
Ion suppression
Reduction in analyte ionisation caused by a co-eluting species or a mobile-phase additive. Trifluoroacetic acid is a strong suppressor.

Where this term appears

The glossary exists to make record pages readable without a chemistry degree. Every technical term on a report resolves here.