How to improve signal on a shimadzu LCMS-2020

[seb731]

Dear all,

Our team just acquired a Shimadzu LCMS-2020, since we’re new with LC/MS systems we’re having trouble to ionise our products. To start I wanted to analyse products such as guaiacol, vanillin and cinnamic acid. We achieved a good separation on the HPLC (detected with a PDA), but for the MS part I only see noise. We are using water/acetonitrile as a mobile phase. I tried caffeine and we obtained a better signal but for my products cited above the ration signal/noise is very low, and I’m not sure if I ionise properly my products. I saw on a paper [1] that ammonium formate could improve ionization (besides being a good buffer). Has anybody been working with a LCMS-2020.

Thank you for your help

Cheers

[1] Owen BC, Haupert LJ, Jarrell TM, Marcum CL, Parsell TH, Abu-Omar MM, et al. High-Performance Liquid Chromatography/High-Resolution Multiple Stage Tandem Mass Spectrometry Using Negative-Ion-Mode Hydroxide-Doped Electrospray Ionization for the Characterization of Lignin Degradation Products. Analytical Chemistry. 2012 Jul 17;84(14):6000–7.

[Robert Classon]

Simple phenols like you are looking for are easy to do by LCMS, but you need the proper pH and solvent conditions. We have several applications notes on these, including degredation products from lignins. If you Email me with your contact info, I will send you some applications about analyzing guaiacols and related phenols with your Shimadzu LCMS.

Regards,
Bob Classon
LCMS Business Development Manager
Shimadzu Scientific Instruments
Columbia, MD, USA
rjclasson@shimadzu.com

[seb731]

Thank you for your reply Richard, i'm beginning to understand the importance of the mobile phase and additives on LCMS, by the way I had the same answer from another Shimadzu guy. I was reluctant to use NaOH to improve signal because it's not volatile enough and it's not mentioned on the article above. I have some ideas now for my next trials.
Again thank you for your help

Kind regards

[geethaa9999]

Have anybody used LCMS-2020 Shimadzu? Could you please share your experience. This is twice the price of HPLC with PDA. If this LCMS is worth for money, I would like to buy it. This will help me to make the decision. Other LCMS (Perkin Elmer, Agilent) are double the price of Shimadzu and I cannot afford it.

Otherwise I am thinking to buy Agilent HPLC-PDA for now and then upgrade to LCMS after a year. I am eagerly waiting for your advise.

Thanks