Charged aerosol detection and ion pairing reagents

[lorenk]

Hey, has anyone used tetrabutyl ammonium perchlorate with their CAD? Or does anyone have any replacement suggestions? Thanks!!! -Loren

[LuccasLN]

Hi Loren,

I've never used this additive in a HPLC-CAD MP, but i guess it would not be very healthy for your detector. a CAD works through an evaporation process, therefore everything needs to be volatile, so i would stay away from perchlorate anions. also, since there is ionization involved in the process i would say it is not particularly ideal to have tetrabutylamonium since you could experience some ionization interference cominng from the alkylamonium salt.

Please, what exactly are you looking for with this additive? TBA could be used as an IP reagent or a rather unusual silanol blocker while the perchlorate would operate as a chaotropic IP reagent. are you looking for an IP reagent for a basic or an acidic molecule?

thanks!

[itspip]

I am not familiar with that additive in CAD, I used ammonium acetate for my work. I still kept the concentration at 10 mM which worked fine.

LuccasLN has a good point about the ionization interference too. As for potential replacements, maybe check some of the MS literature since CAD is similar in compatibilities with MS.

[Kostas Petritis]

Many many years ago, I published a paper at LCGC where I tested different concentrations of acids and bases and their combination, including ion pairing reagents using an evaporative light scattering detector to test their volatility. Results were presented in a summary table. The reference and a link to a pdf of that article can be found below (I could not find a link to the LCGC Europe paper itself). Aliphatic amines could be used as ion pairing reagents with ELSD.

Petritis et al. Volatility Evaluation of Mobile-Phase/Electrolyte Additives for Mass Spectrometry
February 2002, LCGC Europe, 15(2):98-102

https://alfresco-static-files.s3.amazon ... e-9090.pdf