Chromatography Forum

Has anyone had any luck analyzing this compound via LC/MS/MS without hydrolyzing? I am using a Waters Acquity, C18 column, and mostly organic gradient 70% to start. I am unable to see the m/z at the MW upon infusing.

Haven't done the butyl ester, but I have done 2,4-D, 2,4-DP, and 2,4-DB with a C18 column. 0.05% acetic acid and methanol, ramp from 15% organic to 95% organic.

As you already know though, the ESI ionization is going to be quite different for an ester vs. a carboxylic acid. How did you do your infusion? What concentration, what solvent, did you try both positive and negative mode, etc?

I did 2,4-D before using C18 with 0.1% Formic acid/Acetonitrile and it worked well using negative ESI. Not sure how the ester would do though.

I used a syringe at 50 uL/min. I tried infusing a few different formulations – 100 ppb in methanol, 10 ppb in water, and 1 pmm in water. I tried both positive and negative modes.

Thanks,

I used a syringe at 50 uL/min. I tried infusing a few different formulations – 100 ppb in methanol, 10 ppb in water, and 1 pmm in water. I tried both positive and negative modes.

Thanks,

You will probably want to infuse in the solvent mixture that is equal to the mobile phase. If you start at 70% organic I would use that during they infusion. What modifiers are you using? You will need something like Formic or Acetic acid so you can generate ions.

Infusing directly into your MS for tuning? You'll probably want to use a higher concentration. 5 ppm perhaps 10 ppm. What system are you using?

I usually infuse in 50% organic with the analyte at 10ppm. Give that a try with 0.05% or 0.1% acetic or formic acid and see what you get.