LCGC Europe-09-01-2006

LCGC Europe

Gradient Performance Problems — A Case Study

September 01, 2006

LC Troubleshooting

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The gradient linearity and step tests are two of the most useful performance tests that can be made for a liquid chromatography (LC) system. These check the linearity of gradient generation and the accuracy of mobile phase proportioning. These tests, and examples of problems detected as a result of these tests, have been the subject of at least seven "LC Troubleshooting" columns over the last 18 years.1–7 We strongly recommend that every LC system undergo these tests at least on an annual basis, and preferably semiannually. When a new and different example of a problem detected by these tests is discovered, it is hard to bypass the opportunity to share it with our readers. So this month, you get yet another example of how an LC system can fail.

The Possibilities and Limitations of Capillary Extraction (CEx): The Case Study of Polycyclic Aromatic Hydrocarbons (PAHs) in Clean-water Samples

September 01, 2006

Capillary Extraction

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Capillary extraction (CEx) is used to study the solventless in-tube extraction of naphthalene, acenaphthene, phenanthrene, fluoranthene, chrysene, benzo(a)pyrene and coronene in aqueous samples prepared by analyte spiking into clean waters or, as an alternative, by using the generator–column method of sample preparation. Analysis of laden extractors is conveniently performed by high-resolution gas chromatography (GC), with a flameionization detector (FID). Extraction set-ups and main extraction variables are investigated from a practical point of view. For 2- to 4-ring polycyclic aromatic hydrocarbons (PAHs), equilibrium times are within a few minutes, analytical sensitivity is in the parts-per-billion (ppb) range and reproducibility is better than 10% relative standard deviation (RSD) (n = 6). Coronene behaviour is unique and presumably determined by extreme hydrophobicity and thus very negligible aqueous solubility: in-tube extraction of coronene seems possible only if starting from oversaturated..

Mapping the history of human migration

September 01, 2006

News

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Applied Biosystems has joined the Genographic Project as a supporting sponsor for the generation of one of the world's largest databases of information, which will reveal the sources of humankind's diversity. The company has signed a multi-year agreement to provide laboratory research equipment and services to each of the ten participating global research centres. The terms of the agreement were not disclosed.

Experimental Design Approaches in Method Optimization

September 01, 2006

Practical Data Handling

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An experimental design can be considered as a series of experiments that, in general, are defined a priori and allow the influence of a predefined number of factors in a predefined number of experiments to be evaluated.

New Technologies

September 01, 2006

New Technologies

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Now there's light in the "black hole" - of a brief case. German-based international leather and bag specialist BREE has created the first illuminated business handbag with Smart Surface Technology. Bree put their trust in innovative solutions. They say, "We had been toying with the idea of illuminating the dark insides of handbags for quite some time, but lacked an elegant solution which not only met our traditionally high demands with regard to style and function, but was also technically feasible."