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LCGC North America

Temperature affects not only retention but also relative retention in gas chromatography (GC) and therefore, when we change temperature, we also change the selectivity of the separation. This is true as we alter the isothermal separation temperature, but also as we change the slope of the temperature program gradient.

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Special Issues

Internal standard methods are used to improve the precision and accuracy of results where volume errors are difficult to predict and control. A systematic approach has been used to compare internal and external standard methods in high performance liquid chromatography (HPLC). The precision was determined at several different injection volumes for HPLC and ultrahigh‑pressure liquid chromatography (UHPLC), with two analyte and internal standard combinations. Precision using three methods of adding the internal standard to the analyte before final dilution was examined. The internal standard method outperformed external standard methods in all instances.

LCGC Asia Pacific

The CAMAG TLC-MS Interface allows for rapid and contamination-free elution of TLC/HPTLC zones with online transfer to any given HPLC-MS system. Depending on the MS, substances can be identified within a minute.

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The Column

Stereoisomers of chiral compounds - two different forms (isomers) that are identical in composition but are non‑superimposable mirror images of one another - can have dramatically different effects in the human body making it important to ensure the purity of enantiomeric mixtures produced in drug development.

The Column

Gyula Vigh, Emeritus Professor of Chemistry and inaugural holder of the Gradipore Chair in Separation Science at Texas A&M, has been awarded the Arnold O. Beckman Award for Outstanding Scientific Achievements in the field of electrodriven separation techniques sponsored by Sciex Separations, a division of AB Sciex (Massachusetts, USA).

The Column

VWR, a global distributor of analytical products headquartered in Pennsylvania, USA, has announced its acquisition of the analytical instrumentation manufacturer Hichrom Limited based in Berkshire, UK.

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In developing countries, access to medicine is often limited. To make matters worse, widespread counterfeiting often means that even when patients get access to drugs, the drugs are of poor quality. Dr. Mélisande Bernard, of the Agence Générale des Equipements et Produits de Santé, the technical and pharmaceutical service of the public hospital system of Paris, France (Assistance Publique–Hôpitaux de Paris), is helping to address this problem by developing chromatographic methods to detect substandard cardiovascular drugs in Africa.