It is an ion-pairing agent that sharpens chromatographic peaks, improving the separation the purification depends on. It also keeps the mobile phase acidic, which suits most peptides.
The cost is that it does not entirely wash out. Lysine and arginine side chains are protonated under those conditions and pair with trifluoroacetate, and that pairing survives lyophilisation.
A peptide rich in basic residues carries proportionally more counter-ion, and the salt can account for a noticeable fraction of the weighed mass. HPLC purity does not see it, because it does not absorb at the detection wavelength.
This is one of the two main contributors to the gap between purity and net peptide content, the other being absorbed water. A certificate reporting both is giving you what you need to calculate from.
For most research applications the counter-ion is inert background. It matters when the exact peptide quantity has to be known, and in sensitive cell work, where TFA has been reported to affect some assays at sufficient concentration.
Where that is a concern, peptides can be supplied as a different salt form. What a buyer should do in any case is read the residual solvent line rather than stopping at the purity percentage.
It is an ion-pairing agent that sharpens chromatographic peaks, improving the separation the purification depends on. It also keeps the mobile phase acidic, which suits most peptides.
No. REVIVE LAB UAE supplies research materials and provides no dosing, administration or protocol guidance of any kind. Every product is sold for laboratory research use only and is not for human or veterinary consumption.
Stock is held in Dubai. An order confirmed before 4 PM Dubai time is dispatched the same working day, reaching Dubai and Abu Dhabi the same day and the remaining emirates within 24 hours. Delivery is AED 40 flat and free over AED 700.
Supplied for laboratory research use only. Not for human or veterinary consumption. REVIVE LAB UAE provides no dosing, administration or protocol guidance.