LCGC Europe-07-01-2018

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LCGC Europe

Comprehensive two-dimensional liquid chromatography (2D-LC) was used for detailed profiling of various nonionic ethoxylated surfactants applied in pharmaceutical formulations. Hydrophilic-interaction chromatography (HILIC) and reversed-phase liquid chromatography (LC) were used as the first and second dimensions, respectively. Detection was performed with evaporative light-scattering detection (ELSD) for general profiling and with single-quadrupole mass spectrometry (MS) for structure elucidation of individual peaks and for class-type confirmation of peak-groups.

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LCGC Europe

The 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.

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LCGC Europe

While 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.

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LCGC Europe

This 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.