Column Watch: Methods for the Passivation of HPLC Instruments and Columns

Abstract

Metal-analyte interaction is a type of nonspecific adsorption (NSA) that occurs mainly between acidic analytes and active adsorptive sites present in the metal surfaces of the fluidic path of any chromatographic system. NSA represents a chromatographic challenge since it may lead to poor peak shape, low recovery, and poor performance from the high performance liquid chromatography (HPLC) system. As a result, many solutions that circumvent and mitigate this type of secondary interaction have been published or commercialized in the last few years. Such solutions encompass swapping stainless steel components for non-reactive polymers, “biocompatible” metals or alloys, the addition of additives into the mobile phase, pretreating the system with large amounts of sample or strong acids, and the use of coated stainless steel materials. This article explores these solutions in more detail, particularly the recent adaptation and benefits of coated metal surfaces in LC.