what is cut off for tetraalkylammonium sal (HPLC) ?

[JOCAPEN]

I m sorry friends, but I have one doubt.....I need to analysis for organic acids, but the literature recomends TBA....I know the advantages when you use this ion par, but I have been problems because the low wavelength (2100 nm UV detector) for 0,002M TBAI pH 3,5 mobile phase??

[Uwe Neue]

You can purchase a version of this reagent that is good for use down to 200 nm from Waters: low-UV PIC A, part number WAT084189

[JOCAPEN]

Now, I need to check the specification about the PIC-A Waters, but are you now the criteria (TBA/ cloride/ phosfate or sulfate) for ionic compounds....

[Bruce Hamilton]

Just to clarify, if I recall correctly, Waters PIC A ( tetrabutylammonium ) comes as two forms.

"Low UV PIC A" ( tetrabutylammonium hydrogen sulphate ) which can be used down to 200nm, and "PIC A" ( tetrabutylammonium phosphate ) which can be used down to 240 nm. Those cutoffs apply to the recommended concentrations.

Make sure to look at the correct product specifications. There are pure forms of tetrabutylammonium salts available from Romil, Sigma-Aldrich, and other suppliers.

Bruce Hamilton

[Uwe Neue]

Ion-pair reagents have been sold by Waters since the 1970s, and the high-purity form has been sold since at least the early 1980s. Waters was a leading supplier of these reagents, whose use goes back to the work of Brian Bindlingmeyer, who was then a Waters employee, and his team.

[JOCAPEN]

This question about TBA...started with the article Determination of glycolic acid in cosmetic products by solid-phase extraction and reversed-phase ion-pair high-performance liquid chromatography...this work have been used TBAI but 210 nm UV detection.....but I know this salt is no good, when used low UV....sometimes....is possible