Dears,
I'm developing a method for acrylammide quantification in LC-MS/MS (ion trap). The method features are the following:
- ionization ESI+
- C18 column
-10 microL inj V
-mobile phase H20 / 10% MeOH / 0.1% Formic acid (isocratic)
-acrylammide is extracted in ACN
-the MS/MS conditions were optimised for the target compound (m/z 72 to 55)
After MS/MS conditions optimization I ran some analysis with acrylammide plus the internal standard which is deuterated acrylamide (m/z 75 to 58) in order to built my calibration curve but the peak of the IS was splitted in clearly two different peaks. I do not thing that there is any problem of overloading as the signal is quite low and also I tryed to diluit before injection the sample with the mobile phase to avoid issue linked to the different pH but the results were the same. This splitting occurred only on the deuterated internal standard while the acrylammide peak is well shaped.
Any suggestion about how to solve the problem?
Thanks
Need to see the chromatogram to determine the retention time. What is the % purity of your IS? Read it from the CoA (certificate of analysis)
need to see chromatogram or retention time information. What is the retention time for solvent front (Non-retention peak) and Rt of your IS?
Dear,
find enclosed a picture of the chromatogram. In the upper part there is the IS peak splitted while in the lower there is that of acrylamide, not splitted.
I think what you see on the top chromatogram is not the peak splitting, but you see IS and the native standard at the MRM you are monitoring. To prove this, please inject only IS into the LC/MS. You should see only one peak. Please send me the update.
Is there any difference in the way you treat the IS stock or the Calibration stock? It could potentially be contamination. Unlikely to be splitting as the IS should behave in the same way as your parent compound. You could have also potentially contaminated one of the stock solutions?
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