Tivadar Farkas | Authors


LC Column Technology: The State of the Art

In this extended special feature to celebrate the 30th anniversary edition of LCGC Europe, leading figures from the separation science community explore contemporary trends in separation science and identify possible future developments. We asked key opinion leaders in the field to discuss the current state of the art in liquid chromatography column technology, gas chromatography, sample preparation, and liquid chromatography instruments. They also describe the latest practical developments in supercritical fluid chromatography, 3D printing, capillary electrophoresis, data handling, comprehensive two‑dimensional liquid chromatography, and multidimensional gas chromatography.

Additional Studies in the Separation of PEGylated Proteins by Reversed Phase Chromatography

Additional studies were undertaken to better understand the chromatographic behavior of PEGylated proteins in an effort to improve purification and characterization techniques of such proteins. Proteins were PEGylated using larger (20 KDa and 40 KDa) PEGylation reagents that are commonly used in pharmaceutical drug development. Generated PEGylated proteins were separated from unmodified proteins using different reversed phase medias (Jupiter® C4 and Jupiter® C18). In these studies it was found that the Jupiter C18 media provided the best separation of PEGylated proteins from their unmodified counterparts. Such results further clarify good method starting points for developing analytical and preparative separations of PEGylated proteins.

High-Speed Analysis of b-Blockers and Metabolites in Human Plasma by LC–ESI-MS-MS with High-pH Mobile Phase

Beta-blockers are basic compounds that contain a secondary amino group in their structure. The amino substituents are typically an isopropyl group and a larger chain with a hydroxyl group in the beta position from the nitrogen atom (Table I). The simultaneous analysis of ?-blockers in biological samples is meaningful, and is made possible by the similarities in their structure. Gas chromatography (GC)–mass spectrometry (MS) has been the most used technique for their identification and quantification (4–6). However, most ?-blockers are nonvolatile and thus require derivatization via a cumbersome and time-consuming process before GC–MS analysis. In recent years, liquid chromatography (LC) coupled with mass spectrometric detection has evolved as the method of choice for drug analysis in the pharmaceutical, clinical, and forensic toxicology areas (4–8). In contrast to GC–MS, LC–MS-MS generally does not require derivatization and offers superior sensitivity. Moreover, due to the high specificity offered by LC–MS-MS, baseline chromatographic resolution often is not required, allowing for fast analysis in high-throughput environments.