HPLC

Following on from a previous instalment, this month's column assesses evaporative light-scattering detection as a complementary detection mode and builds upon the previous discussion in terms of detector applications.

In this month's column, the authors present a relatively simple method for selecting the appropriate curve-fitting function and thus ensure that the requirements of current guidelines can be met.

This month'ss "Column Watch" is the first of a two-part series that examines new column introductions at Pittcon 2004.

Evaporative light-scattering detection offers a complementary detection mode that can detect nearly all eluted compounds in either isocratic or gradient conditions.

Which curve-fitting function should be used?

This article establishes the estimation of the uncertainty associated with the chromatographic determination of biogenic amines.

Peaks that are too broad can mean that analysts are not using their LC columns very efficiently. In this month's column, John Dolan describes how to determine if peaks are broader than they should be and highlights some of the common system-related causes of peak broadening.

In this article the authors report on a combinatorial natural product discovery methodology that uses a viral vector system to transfer secondary metabolite-related enzymes from C. roseus to tobacco cell cultures. Using high-resolution separation techniques, including HPLC, CE and MS, they describe the analysis of secondary metabolite patterns.

This month's column examines several possible causes of peak splitting and presents some guidelines for isolating the problem source.

Two solutions to the problem of obtaining quantitative information about protein expression are to couple two or more chromatographic modes to increase resolution and to use affinity selection techniques.

Tim Wehr looks at the requirements of multidimensional LC and provides examples of some systems used in proteomics.

Tim Wehr looks at the use of fast LC}MS for high-throughput analysis of pharmaceutical compounds.

This month Tim Wehr discusses traditional approaches to protein characterization.

The authors investigated the analytical capabilities of quadrupole, time-of-flight, and Fourier transform mass analyzers for liquid chromatography electrospray mass spectrometry (LC-MS) applications.

How can you avoid phase collapse when 5% organic solvent is too strong?

This month's "Column Watch" describes moving bed chromatography and how the concept is realized in the form of simulated moving bed chromatography. Also included is an inside look at instrumentation, method development, and applications for industrial purifications.

How can internal LC surfaces be made less reactive?

This installment of "Milestones in Chromatography" looks at two major international meetings held in Las Vegas, Nevada, and Seattle, Washington, that were pivotal in the early development of HPLC.

This month's "Directions in Discovery" gives a brief overview of turbulent- flow liquid chromatography, a technique for fast separations. Two examples demonstrate the use of the technology for high-throughput bioanalytical separations in drug discovery.

Given the increasing number of chiral samples and the time constraints under which chromatographers work, choosing an appropriate chiral stationary phase for the resolution of enantiomers can be challenging. In this article, the authors describe a screening approach for chiral HPLC method development.

Stainless steel is inert – or is it?

This month's "Column Watch" examines developments in column packings. Ron Majors looks at the physical design of packing materials from a performance standpoint and discusses some new packing materials that have unique characteristics.

A scouting gradient is a separation run under a standardized set of conditions and can be used to determine the complexity of a sample and estimate the difficulty of the separation. John Dolan tells why he believes using a scouting gradient is the best way to begin method development.

This "Data File" column shows readers how to incorporate e-mail in chromatography data systems and suggests how other Internet technologies can improve modern laboratory practices.

During the past five years, many manufacturers of HPLC columns have focused on improving stationary phase stability and reproducibility. In this study, the authors use a variety of test solutes to compare the efficiency, selectivity, and hydrophobic retention mechanisms of five commercially available HPLC columns based silica, alumina, zirconia, and polystyrene cross-linked with divinylbenzene as the support.