7:00pm – Presentation- Horacio Pappa, USP
USP Column Equivalency Application: A web-based searchable database offered by USP
Abstract:
The L nomenclature to designate HPLC column types was introduced for the first time in the Fourth Supplement to USP XIX in 1978. Since then the list has grown without pause to 56 descriptions, some of them very broad or with imprecise wording.
For years, this classification system has generated an increasing number of inquiries to USP regarding which column brand is appropriate for a particular compendial procedure. Today, column packings are developed for specific applications, resulting in columns with distinct characteristics even though they belong to the same original USP classification. For example, more than 220 columns currently available in the worldwide market can be classified as L1, but not all of them have the same applications. This situation makes the process of selecting a column for a particular application very difficult.
It is evident that the current classification nomenclature does not provide sufficient information to fulfill the needs of modern liquid chromatography. In an attempt to facilitate the selection of possible columns by the analyst, USP created a website that allows users to search for equivalent columns. The website offers two different approaches; one based on the use of the NIST Standard Reference Material 870, the other developed by Dr. Lloyd Snyder and studied by PQRI.
7:30pm – Presentation- Ronald E. Majors, Ph.D., Agilent
Considerations in High-Throughput and High-Resolution HPLC
In analytical HPLC column technology, there are a number of approaches for developing faster or higher efficiency separations. Most recently the increased use of sub-2-um particles packed into short columns has generated faster separations without sacrificing resolution of the longer columns packed with larger 5-um particles. Longer, high-resolution columns packed with these tiny particles do generate greater pressure. Compared to 5-um columns, columns packed with 2- to 3-um particles provide higher throughput but the efficiency is not as good and the pressure drop is not as high as the sub-2-um columns. Superficially porous particles for large and small molecules provide lower pressure drop than the sub-2-um and offer shorter diffusion path lengths and better efficiency than the 2- to 3-um particles. Monoliths represent another approach for increased speed but flow rates are higher than required for satisfactory MS detection but work is proceeding to come up with smaller internal diameter silica-based monoliths. Instrumentation such as detectors, data systems and mass spectrometers may be challenged to keep up with rapidly eluting peaks coming from high speed columns. High temperature can be used as a variable to further improve throughput, modify selectivity and provide lower pressure drop. This presentation will discuss the pros and cons of each approach and make some recommendations for optimal use of columns of each type.
Biographical Sketch:
RONALD E. MAJORS, Ph.D.
Since 1990, Ronald E. Majors has been employed by Hewlett-Packard/Agilent Technologies, working in the area of sample preparation and chromatography column technology. His current position is a Master Scientist in the Columns and Supplies Division. Ron received his B.S. in chemistry at California State University, Fresno, in 1963 and his Analytical Chemistry Ph.D. degree in 1968 from Purdue University under the direction of L.B. Rogers. His Ph.D. thesis was in the area of molecular-imprinted phases for chromatography and sample preparation. He is the author of over 250 publications in HPLC, GC, sample preparation and surface chemistry. Among his current activities, he is editor for the monthly features, "Column Watch" and "Sample Preparation Perspectives" in LC/GC Magazine for which he is also serves on the Editorial Board. Dr. Majors has served as Chairman of HPLC '86 and Anabiotec '90 and as a member of the Instrumentation Advisory Board of Analytical Chemistry. His current interests include sample preparation especially solid-phase extraction and automation, and HPLC and GC column technology. Ron is a lifetime member of The Chromatography Forum of Delaware Valley, a member of the American Chemical Society, The Chromatography and Separations Chemistry Sub-division of the Analytical Division of the ACS where he had served as Chairman and Secretary. He is also a member of the Chromatographic Society (U.K.) and is a member of the Board of Directors for the California Separations Society (CaSSS). Ron has been an invited lecturer, session organizer, and session chairman at many national and international symposia. Dr. Majors was the 1994 recipient of the Merit Award in Chromatography from the Chicago Discussion Group, the 1998 Award for Distinguished Contributions in Separation Science sponsored by the California Separations Society and, in 2000, the "Salutes to Excellence" Award from the North Jersey Chromatography Discussion Group, the 2006 Palmer Award from the Minnesota Chromatography Forum and, most recently, the Chromatographic Society’s 2007 Martin Gold Medal from the United Kingdom, named for the Nobel Prize winner, A.J.P. Martin.