I just recieved a column from SIELC with an aplication for the analysis of thiamine pyrophosphate(TPP) and pyrodoxin 5'-phosphate(PLP)( thanks for the help Vlad Orlovsky from SIELC!). Both were doing fine in the lab of SIELC (i don't know wat lc they usd) but when i run the aplication on my lab, PLP is doing fine but TPP gives a very broad tailing peak. I run the aplication with 0,05 mM formic acid without the column and sea the same: good peak for PLP, broad tailing peak peak for TPP. When i inject without column at pH 9.5 both peaks are fine. i use an infinity 1290 lc with mass spec. does anybody know wat is wrong with my lc and how o solve this?