LCGC North America, Mar 1, 2005 - Chromatography Online
LCGC North America, Mar 1, 2005
Column Watch
New Chromatography Columns and Accessories at the 2005 Pittcon Conference: Part I
By Ronald E. Majors
Pittcon 2005 — the 56th Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy — returned to the Orange County Convention Center, Orlando, Florida, 27 February-4 March 2005. This year's event hosted more than 900 instrument manufacturers and 1aboratory suppliers in more than 2300 booths. In addition to attending the exposition, the conferees were able to listen to numerous oral presentations, view more than 900 posters, check out 38 seminar rooms, or attend one of 150 short courses.
3
Split Peaks — A Case Study
By John W. Dolan
Case studies are good ways to look at specific examples of common liquid chromatography (LC) problems and to draw general conclusions that can be applied to prevent similar problems from happening for other workers. The example in this month's installment of "LC Troubleshooting" comes from a reader who works in the pharmaceutical industry. The sample is a cold-cough syrup analyzed with an ion-pairing LC method. I have disguised the details somewhat to protect the proprietary nature of the method, but there should be sufficient information to help us gain some knowledge of the peak-splitting problem experienced by the user.
GC Connections
What's in a Method?
By John V. Hinshaw
The best approach is to document everything for each hardware configuration as a separate method and then qualify and validate them for each sample or category of sample.
Directions in Discovery
Chromatography Applications in Drug Discovery of Therapeutic Proteins
By Paul K. Ng , Michael H. Coan , Tim Wehr
In this month's installment of "Directions in Discovery," the authors discuss how, with the arrival of combinatorial libraries and high-throughput screening, pharmaceutical firms can develop new models of drug discovery that not only lessen the initial capital outlay involved in drug discovery, but also refine the discovery process.
News
Characterization of Hyaluronic Acid with On-Line Differential Viscometry, Multiangle Light Scattering, and Differential Refractometry
By Jason Waters , Danielle Leiske
Hyaluronic acid (HA) is a naturally occurring, unbranched polysaccharide that consists of alternately repeating D-glucuronic acid and N-acetylglucosamine units. This biopolymer is present throughout all mammalian systems but occurs primarily in synovial (joint) fluid, vitreous humor, and various loose connective tissues (such as rooster comb) (1). HA is of enormous commercial interest for ophthalmic, medical, pharmacological, and cosmetic applications.
Planar Chromatography Versus Column Chromatography: A Performance Comparison
By Pawel K. Zarzycki , Kathrin M. Kulhanek , Roger Smith , Malgorzata A. Bartoszuk , Henryk Lamparczyk
It is hypothesized that in particular cases, conventional planar chromatography provides a more effective and robust system than column chromatography with regard to separation efficiency and peak distribution of mixtures composed of low-retarded analytes. Under similar reversed-phase experimental conditions, a regular distribution of thin-layer chromatography (TLC) spots of four natural estrogens (estetrol, estriol, 17?-estradiol, and estrone) corresponds to strong irregular dispersion of peaks in chromatograms generated by high performance liquid chromatography. In both cases, the efficiency of separation was assessed using simple optimization criteria such as selectivity (?min) and resolution (Rs min). The distribution of chromatographic spots was evaluated using the relative resolution product (r). The results revealed that an excellent separation of the components of interest could be achieved easily using simple nonforced and isocratic TLC. Such an interesting property of planar chromatography is mainly driven by the nonlinear relationship between k and Rf retention factors. This article also reports the practical advantages of TLC for the separation of estrogenic steroid mixtures at different temperatures.
Departments
Calendar
Calendar
Peaks of Interest
Science center awarded $25,000 grant
Products
ESA's model 530 HPLC fluorescence detector uses a 3-D optical design reported to reduce loss of light and increase sensitivity.
Literature
2005 TLC catalog
Short Courses
SHORT COURSES

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LCGC COLUMNISTS 2014

Sample Prep Perspectives | Ronald E. Majors: Ron Majors, established authority on new column technologies, keeps readers up-to-date with new sample preparation trends in all branches of chromatography and reviews developments.
LATEST: UV Detector Problems


Perspectives in Modern HPLC | Michael W. Dong: Michael W. Dong is a senior scientist in Small Molecule Drug Discovery at Genentech in South San Francisco, California. He is responsible for new technologies, automation, and supporting late-stage research projects in small molecule analytical chemistry and QC of small molecule pharmaceutical sciences. LATEST: Superficially Porous Particles: Perspectives, Practices, and Trends


MS — The Practical Art | Kate Yu: Kate Yu brings her expertise in the field of mass spectrometry and hyphenated techniques to the pages of LCGC. In this column she examines the mass spectrometric side of coupled liquid and gas-phase systems. Troubleshooting-style articles provide readers with invaluable advice for getting the most from their mass spectrometers. LATEST: Radical Mass Spectrometry as a New Frontier for Bioanalysis


LC Troubleshooting | John Dolan: LC Troubleshooting sets about making HPLC methods easier to master. By covering the basics of liquid chromatography separations and instrumentation, John Dolan is able to highlight common problems and provide remedies for them. LATEST: Problems with Large-Molecule Separations


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