LC-MS¶

Definition¶

Liquid Chromatography Mass Spectrometry (LC-MS) is a hyphenated analytical technique that combines the separation power of HPLC with the detection and identification capability of mass spectrometry.

Overview¶

LC-MS is a powerful tool for peptide analysis that simultaneously provides both separation (like HPLC) and molecular weight identification (like MS). It is widely used for identity confirmation and detailed impurity characterization.

Technical Explanation¶

How LC-MS Works: 1. HPLC separates sample components by retention time 2. As each component elutes, it enters the mass spectrometer 3. The MS ionizes the compound and measures mass-to-charge ratio (m/z) 4. Data is presented as a total ion chromatogram (TIC) plus mass spectra for each peak

Advantages Over HPLC Alone: - Simultaneous separation and identification - Each peak is identified by molecular weight - Can distinguish co-eluting compounds with different masses - Provides structural information through fragmentation (MS/MS) - Higher sensitivity for impurity detection

Importance in Peptide Documentation¶

LC-MS provides the most comprehensive quality assessment — combining purity (HPLC separation) with identity (mass confirmation). RPL Peptide uses LC-MS for identity verification and impurity characterization in its quality control workflows.

Frequently Asked Questions¶

Q: Is LC-MS better than HPLC for purity analysis? A: LC-MS provides additional identity information for each peak, making it superior for impurity identification. However, HPLC with UV detection remains the standard for quantitative purity determination due to better UV response linearity.

Q: Does every COA include LC-MS data? A: Most comprehensive COAs include LC-MS data for identity confirmation. Purity is typically reported from HPLC-UV analysis. RPL Peptide COAs include both HPLC purity data and MS identity confirmation.