Fluorinated HPLC Phases — Looking Beyond C18 for Reversed-Phase HPLC
January 1st 2006Guest columnist Matt Przybyciel reviews the structure, behaviour and applications of both alkyl- and phenyl-fluorinated phases in HPLC. The author presents some guidelines on potential areas of application for alkyl and phenyl-fluorinated phases, in which conventional C8, C18 and phenyl phases might have insufficient selectivity or too strong retention.
The Thermal Conductivity Detector
January 1st 2006Thermal conductivity detectors have been in use since before the beginning of gas chromatography. Essential for fixed-gas detection - no substitute has the same ease of use and stability - thermal conductivity detectors also are employed when the auxiliary or combustion gases required by flame ionization or other detectors are unsafe or impractical. Although they cannot match the sensitivity of ionization detectors, thermal conductivity detectors are the third most used detector, surpassed only by flame ionization and bench-top mass-spectrometry detectors. This month's installment of "GC Connections" takes a look at the operating principles and inner workings of the thermal conductivity detectors.
Precise Sample Preconcentration Coupled with Automated Sampling
December 2nd 2005Dionex has developed an autosampler with very precise sample preconcentration capabilities. When analyte detection is no longer possible even with a large loop injection, sample preconcentration (loading a sample through a concentrator column and eluting the concentrate) is used.
Application Notebook - December 2005
December 1st 2005Contents:- Recent Developments in Columns for UPLC- Transfer of the USP Human Insulin Related Compounds HPLC Method to the ACQUITY UPLC System- Validation of a UPLC Method for a Benzocaine, Butamben, and Tetracaine Hydrochloride Topical Solution- Meeting Analytical Challenges with UPLC-MS- Enabling Significant Improvements for Peptide Mapping with UPLC- Analysis of Prostaglandins with the Quattro Premier XE