Liquid Chromatography (LC/HPLC)

I attended session 220, "Sample Preparation: General," on Sunday afternoon. As Frank Dorman of Restek Corporation, who presided over the session noted, the weather here is much nicer than it was last year in Chicago, and he was happy to see a good crowd gathered for this session.

Given the historic and crucial relationship between New Orleans and the sea, it was appropriate to kick off the Pittcon week with a nautical-based session.

A proud student filling in for his esteemed teacher highlighted the first day of technical sessions as Pittcon returned to the Crescent City.

Sunday afternoon's plenary lecture at Pittcon 2008 was presented by Dr. Leroy Hood, President of the Institute for Systems Biology in Seattle, Washington. The lecture was preceded by the Pittcon Heritage Award presentation, which was awarded to Hood.

Pittcon 2008 got off to a great start here in New Orleans. The liquid chromatography sessions at the Ernest N. Morial Center were interesting and informative, such as the session entitled "Liquid Chromatography at the Extreme: Ultra-pressure and High Temperature."

Good morning and welcome to this, LCGC's third year of live, daily coverage from The Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy.

A very efficient way to start an isocratic method development project is to make the first run as a scouting gradient run.

This study evaluates the use of HPLC to estimate the log P (the octanol–water partition coefficient) of two compounds, apocynin and diapocynin. The paper will discuss the effects of an unexpected reversal of retention that occurred when these compounds were chromatographed with various amounts of methanol–water mobile phases.

Trade extra resolution for speed.

Screening for important factors during method optimization or in robustness testing involves two-level screening designs, such as fractional factorial and Plackett–Burman designs, as described in Part 1. This second part on screening designs discusses the experimental protocol for executing these designs and the data analysis of their results.

The use of dual polarization interferometry (DPI) to measure the behaviour of alkyl-modified surfaces under different solvent regimes is described. The empirically observed and modelled behaviour of grafted long alkyl chain adlayers on a silica surface were in good agreement. The empirical data was also compared with data using analogous systems and these also matched well. This approach has the potential to gain much greater insight into the behaviour of reversed-phase (RP) columns and could help to design column surfaces that are resistant to phase collapse.

In 2001, the second glossary of common and not-so-common terms and "buzz words" for reference to HPLC columns and column technology was published. It is time for an update since new terms have arisen or, in some cases, their original meanings have expanded or changed.

High performance liquid chromatography (HPLC) enhances throughput in countless processes, including environmental analysis, dissolution testing, separation of biomolecules, and total drug analysis. To take advantage of the benefits of HPLC technology, samples and solvents must be cleared of particulate contaminants. Doing so protects instrument components and minimizes maintenance costs. This article outlines HPLC technology, explains the importance of sample preparation, and reviews the factors that must be considered when preparing HPLC samples by membrane filtration. The data from experiments to test these factors show that the physicochemical characteristics of membrane filters can affect HPLC results.

In this installment of "Column Watch," Ron Majors examines the various approaches to increasing the speed of high performance liquid chromatography (HPLC) separations.

How to avoid an expensive shot in the dark.

The retention behaviour of several compounds has been compared for their selectivity using reversed-phase high performance liquid chromatography with binary water mobile phases composed of methanol, acetonitrile or tetrahydrofuran as modifiers.

BMC Pediatrics reports on a study characterizing total homocysteine (tHcy) levels at birth in preterm and term infants and identifing associations with intraventricular hemorrhage (IVH) and other neonatal outcomes such as mortality, sepsis, necrotizing enterocolitis, bronchopulmonary dysplasia, and thrombocytopenia.

Gerald Drager and colleagues from University of Hannover in Leibniz, Germany, have developed a system that enables immobilization and purification of enzymes in the same reactor, which can then be used for a variety of enzymatic syntheses. Using this technique it is possible to obtain ready-to-use enzyme reactors from crude protein mixtures within minutes.

A new study by Frost & Sullivan shows that the liquid chromatography (LC) market in the U.S. will grow from an estimated $596.3 million in 2006 to $1.018 billion by 2013, thanks to increasing interest and use from both the commercial and research communities.

Nanostream (Pasadena, Calif.) has launched a portal for its customers to deliver real-time access to company and product information. The portal will also act as a way to facilitate troubleshooting for the company's micro parallel liquid chromatography (uPLC) products and provide product updates.

For the last six months, "LC Troubleshooting" has been concentrating on the process for the development of isocratic methods (those for which the mobile phase composition is constant throughout the run). The use of a gradient scouting run to speed isocratic method development is the subject of this month?s "LC Troubleshooting."

Proteins can be separated according to their isoelectric points on an ion-exchange column using pH gradients in the first dimension and according to their hydrophobicity on an RP column in the second dimension.

How do I get the most out of my efforts?