The document discusses PEEK columns for HPLC and LC/MS. PEEK columns offer better chemical inertness compared to stainless steel columns. This reduces issues caused by metallic impurities interacting with analytes like phosphate groups. PEEK columns are available with InertSustain and Inertsil packing materials in particle sizes from 1.9 μm to 10 μm. They provide excellent peak shapes without analyte adsorption. An ordering guide provides the catalog numbers for various PEEK column configurations.