May Meeting Notice
Tuesday, May 8, 2007
HPLC Column Selectivity How to Identify an “Equivalent” Column
Dr. John Dolan
LC Resources Incorporated
Walnut Creek, CA
Abstract:
In the early days of HPLC, it was thought that all C18 columns were equivalent, and this is reflected in the USP L-1 classification of columns. However, as better manufacturing control and a better understanding of the chromatographic process developed, it was realized that most C18 columns are anything but equivalent. Still, it is a common goal of chromatographers to specify a column with equivalent properties to the primary column, in case of unavailability of the primary column. On the other hand, one may want to locate a column that is maximally different from the current column for “orthogonal” separations, where chromatographic selectivity is not the same, to enable the analysis of hard-to-separate mixtures.
This talk will present a status report on an 8-year study comparing column selectivity. Columns can now be tested with a simple test mixture and selectivity can be compared to other columns used to analyze compounds other than the test compounds. The test procedure describes the column quantitatively in terms of hydrophobicity, steric selectivity, hydrogen bonding to non-ionized acids and bases, and cation exchange ability. A database of more than 300 different C18 and C8 columns has been developed that allows one to quickly identify columns that are equivalent or orthogonal. The fundamentals of the test process and several examples of practical applications in the pharmaceutical industry will be presented.
About the Speaker:
Dr. John Dolan is most widely known as the author of LC/GC’s popular LC Troubleshooting column. As editor of this column for over 20 years, Dr. Dolan has contributed more than 250 installments of practical advice to practicing chromatographers. John has written over 100 technical papers, many of which support the development and practical application of gradient elution LC. His book (with Lloyd Snyder), Troubleshooting LC Systems, is a standard reference in laboratories worldwide. A second book (also with Lloyd Snyder), High Performance Gradient Elution, is in press for publication late in 2006. He is the 2002 recipient of the prestigious Palmer Award given by the Minnesota Chromatography Forum, and the nominee for the 2007 Dal Nogare Award given by the Chromatography Forum of Delaware Valley.
Dr. Dolan managed a regional contract research laboratory for 11 years for LC Resources and later Bioanalytical Systems, Inc. The lab, which he helped found in 1988, specializes in the development, validation, and application of LC-MS/MS methods to determine pharmaceutical compounds in biological matrices. In addition, he is one of the founders of LC Resources, Inc., a company dedicated to training chromatographers around the world. As an instructor for LCR and the American Chemical Society, John has instructed more than 10,000 students in practical LC techniques.
Details:
| Location: | Ace Center |
| Times: | 5:00 PM Executive Committee Meeting 5:45 PM Social "Hour" 6:30 PM Dinner 7:30 PM Presentation |
| Cost: | $30 |
| Dinner Choices: | Fabulous buffet including a wide variety of entrees, salads and desserts to suit any palate! |
NOTICE TO STUDENTS AND FACULTY: Full-time students with valid ID may attend dinner meetings at half-price. Faculty members at colleges and universities are urged to bring one or more students to the meeting. If they do, they also can attend at half-price.