Unexpected Drop in Peak Intensity During LC-MS Analysis—What’s Going On?
While analyzing maleic and fumaric acids in a biological extract using a Cogent Diamond Hydride™ column, I observed an interesting phenomenon:
After 10 flawless injections—with retention time %RSD around 0.5—the peak intensities dropped by a factor of 10, yet the retention times remained unchanged.
What happened to the column?
Most likely, nothing is wrong with the column. A sudden drop in signal intensity with stable retention times typically points to an issue with the mass spectrometer, not the chromatography.
We recommend checking the following:
- Clean the ion source – Contamination can significantly reduce signal strength.
- Inspect the nebulizer – Clogs or wear can affect ionization efficiency.
Maintaining your MS system is essential for consistent performance, especially in sensitive LC-MS workflows. The Cogent Diamond Hydride™ column is highly stable and unlikely to be the cause in this scenario.