When Do We Need Sub-2-µm Superficially Porous Particles for Liquid Chromatography Separations?
July 1st 2018The use of superficially porous particles (SPPs) for modern high performance liquid chromatography (HPLC) is now very common. Initially, SPPs rose as an alternative to sub-2-µm fully porous particles (FPPs). In recent years, many column manufacturers have developed 2-µm and smaller SPP-based products. This article investigates the practical utility of these smaller SPP designs.
Split, Splitless, and Beyond—Getting the Most From Your Inlet
July 1st 2018While capillary gas chromatography has been undergoing a renaissance, with new columns, detectors, data systems, and multidimensional separations, the classical inlets have remained the same: We are still injecting liquid samples with syringes into split and splitless inlets, as we have for nearly 50 years. Split and splitless injections present several well-known and some not-so-well known challenges, mostly arising from heating of the inlet, that make sample injection and inlets a major hurdle for gas chromatographers. These challenges and some ideas for mitigating them are discussed and a case is made for renewed exploration of the cool inlets and injection techniques: cool on-column and programmed temperature vaporization.
Data Integrity and USP : Part 1 Specifications and Suppliers
July 1st 2018This is the first of three articles looking at the impact of the new United States Pharmacopeia (USP) chapter on Analytical Instrument Qualification (AIQ) on data integrity in a regulated chromatography labora-tory. In part 1, user specifications for chromatography systems and the relationship between users and sup-pliers will be discussed.