Improving LC-MS Analysis of Basic Impurities Using CORTECS C18+, 2.7 µm Solid-Core Particle Columns

This application note describes use of two structurally similar drugs, imipramine and amitriptyline to simulate a difficult mixture of an API and a closely eluting impurity present at low levels. These compounds present a common analytical challenge. Their basic nature leads to poor peak shape in frequently employed formic acid mobile phase conditions. Such phenomena are mitigated with the CORTECS C18+ columns due to the surface charge present. This technology and the solid-core particles afford superior peak shape and higher MS signal. The result is more accurate and reliable characterization of the impurity peaks using HPLC-MS and UPLC-MS instruments.