Liquid Chromatography (LC/HPLC)

Latest News


This month's "LC Troubleshooting" discussion will center on the recommendations of the CDER document, especially in terms of what it means from a practical method performance standpoint.

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Using a fixed length-variant of the kinetic plot method, it is illustrated how an analysis that is performed near the optimal flow-rate of a given commercial column can, in many cases, be performed between 50–200% faster by switching to a longer column and operating it at a higher pressure - at least, if the available instrument pressure admits so. The present article aims to show that short columns are not always the best choice to get the fastest separation.

Italian researchers in Rome (Universita Cattolica and Consiglio Nazionale delle Ricerche) and Cagliari (Universita di Cagliari) have used reversed-phase high performance liquid chromatography with electrospray ionization mass spectrometry to analyze naturally occurring salivary peptides from subjects with autism and compare the profiles with those obtained from age-matched control subjects.

At the beginning of the year, it is good to look back in time- are there things that we can learn from the past? After a series of troubleshooting and method development seminars in Istanbul, Turkey, and Amman, Jordan, John Dolan looks back.

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An ultrafast gradient LC separation method was developed to separate a 5-component drug mixture in 30 seconds, with peak widths of 1 second. maXis mass accuracy at sub-ppm levels and true isotopic pattern of the spectra from the peaks lead to a confident elemental formula assignment for each drug compound with the SmartFormula algorithm.

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Cytosine (chemical name 4-amino-2-hydroxypyrimidine) is a pyrimidine derivative with a hetereocyclic aromatic ring and two substituents (amine and keto groups) attached and is a polar compound of significant biological and pharmaceutical interest. In response to the intended use of bulk cytosine as a raw material in pharmaceutical manufacturing, a method for the determination of the purity of cytosine was developed.

Scientist Cornelia Kasper and colleagues from the Gottfried Wilhelm Leibniz University of Hanover (Hanover, Germany) thought that a liquid chromatography method with short monolithic columns would be a quicker alternative to measure proteins in culture while also having had the potential to separate different proteins.

LC Pumps

This month's "LC Troubleshooting" installment will take a look at the design of these durable pumps and also examine some of the potential weaknesses and how to overcome them.

All the buzz lately about LC columns packed with particles smaller than 3 mm often comes with warnings about extracolumn effects. This month's installment will take a look at what these effects are and more.

A research group from the University of Lisbon (Lisbon, Portugal) studied the use of stir-bar sorptive extraction (SBSE) with polyurethane and polydimethylsiloxane polymeric phases and high performance liquid chromatography with diode-array detection for the analysis of six acidic pharmaceutical compounds in environmental water matrices such as river, sea, and wastewater samples.