Highlights of HPLC 2009 - - Chromatography Online

Highlights of HPLC 2009

Sep 1, 2009
By: Ronald E. Majors
LCGC North America

Ronald E. Majors

The 34th International Symposium on High Performance Liquid Phase Separations and Related Techniques, which alternates between Europe, Japan, and North America, was held, for the first time, in Dresden, Germany from June 28 to July 2, 2009. More affectionately known as HPLC 2009, the symposium is the premier scientific event for bringing together the myriad of techniques related to separations in liquid and supercritical fluid media. Chaired by Prof. Christian Huber of the University of Salzburg, Austria, HPLC 2009 assembled 1240 scientists from a total of 51 countries. This number included 270 vendor representatives from over 64 exhibitors for the three-day instrument, software, and consumables exhibition. Students constituted nearly a quarter of the conferees, which speaks highly for the next generation of separation scientists. Based upon the number of attendees and exhibitors, the worldwide economic crisis did not play heavily into the support for this important conference.

The five-day plus event had a total of 128 oral presentations in plenary and parallel sessions and over 600 posters in sessions with 20 themes. With an ample social event schedule, 15 vendor workshops (some with free lunch), 12 tutorial educational sessions, and eight short courses, the latter held during the previous weekend, attendees had their hands full deciding how to allocate their time. The tutorials were particularly well attended and covered current topics such as bioanalytical liquid chromatography (LC)–mass spectrometry (MS)-MS, miniaturization, validation, biomarkers, stationary phases, quality by design, speciation, multidimensional LC, microchips, and hyphenated techniques.

Trends in Liquid-Phase Technology and Techniques

Obviously, high performance liquid chromatography (HPLC) was the predominant technology in the technical sessions at the symposium but increased use of electrophoretic techniques, mostly in a capillary format, was strongly evident. From a perusal of the poster and oral presentation abstracts, I broke down some of the major areas of coverage in this year's symposium. These tables are useful to spot trends in the technology, applications of liquid-phase, and detection usage. Many of the topics that are currently "hot" in the separations sciences were introduced in this series.

Table I: HPLC 2009 papers presented by technology or technique

Table I provides a rough breakdown of the coverage of liquid-phase technology and techniques in the separation sciences. Compared with HPLC 2008 (1,2), some slight shifts in technology emphasis were noted. Although column technology always leads the pack, this year, about a quarter of the columns' papers dealt with monoliths, down from a third last year, but with more emphasis on polymeric-based monoliths that have less intelligential property protection compared with silica-based monoliths. Papers dealing with polymeric monoliths outnumbered papers on silica monoliths about 4:1. One exciting new development in polymeric monoliths was those that can separate small molecules; originally the small molecule domain was for the silica-based monoliths only. Three other "hot" areas in column technology this year were the continued interest in sub-2-μm porous packings coupled with ultrahigh-pressure liquid chromatography (UHPLC) instruments; the explosive attention in the technique of hydrophilic interaction liquid chromatography (HILIC) for the separation of polar analytes (23% of all LC column papers touched on this subject); and the new breed of superficially porous packings (also referred to as pellicular, porous layer beads, and fused-core packings) that are said to rival the sub-2-μm particles in terms of column efficiency but with substantially lower pressure drops. A very hot but rather specialized topic was the use multidimensional chromatography — coupled columns, column switching, and the like. Especially strong was the coverage of comprehensive LC×LC, a subject of two thirds of the multidimensional chromatography papers. With chromatographers encountering more complex samples, sometimes with thousands of compounds present, these multidimensional techniques are about the only way to tackle such mixtures.

Sample preparation technology was well represented in the poster papers. Most prominent was solid-phase extraction (SPE) in its various formats: cartridges, pipette tips, 96-well plates, syringe-packed sorbent, as well as selective phases such as molecularly imprinted polymers (MIPs), immunoaffinity phases, restricted-access media, and mixed-mode phases. Liquid-phase microextraction via hollow fibers, electromembrane extraction, and protein precipitation plates with built-in phospholipid removal were new areas getting attention.

Even though there have been reports of its demise, electrodriven separation techniques — for example, capillary electrophoresis (CE), capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), and isoelectric focusing (IEF) — had a strong representation again this year. Recent introductions of improved CE instrumentation on the market could perhaps bring new life into this technique widely used for inorganic anions and cations, enantiomeric compounds, proteins, and drug-stability measurements. A continued lack of interest in capillary electrochromatography (CEC) was noted with only eight presentations at HPLC 2009. Only a few years ago, lecture rooms on CEC topics spilled out into the hallway and the technology was to replace both HPLC and CE. However, the "killer" application for the technique was never found; any separation performed by CEC could be done by gas chromatography (GC), SFC, or LC without all the associated problems.

12 3 4 5 6 7 8 9 10 11 12 13 14