In most cases, peak area is preferred over apex intensity for LC‑MS quantification, as it provides a more robust and reproducible measure of signal. Peak area integrates the full chromatographic peak and is therefore less sensitive to fluctuations in peak shape, retention time shifts, or transient signal noise that can affect the apex.
Apex intensity can be useful in certain contexts, particularly for rapid or high‑throughput workflows, but it is more susceptible to variability and may not accurately reflect total analyte abundance, especially for broader or less well‑defined peaks.

For HCP analysis in a GMP context, where robustness and consistency are critical, peak area–based quantification is generally recommended. That said, the most appropriate approach ultimately depends on the method design and should be supported by proper qualification or validation to demonstrate accuracy, precision, and suitability for purpose.

Thomas Kofoed, PhD, CEO of Alphalyse in Denmark, discussed key factors in implementing GMP-compatible LC-MS methods for release assays and highlighted successful cases where this approach has replaced traditional ELISA methods. Don’t miss his presentation and expert insights at the panel discussion.