"In Praise of Wool": The development of partition chromatography and its under-appreciated impact on molecular biology.

The invention of partition chromatography by the biochemists Archer Martin and Richard Synge in 1941 offered crucial insights into the structure and function of DNA, insights at least as important as those from X-ray crystallography. Even so, the role that partition chromatography played in molecular biological studies is far less well known. Using new archival material, this article describes the origins of Martin and Synge's work, arguing that their achievement was far more than a new technical innovation; it went on to have a profound impact on the development of molecular biology to an extent that scholars have insufficiently appreciated.

Development of capillary liquid chromatography: A personal perspective.

This is a historical account on the development of capillary LC from its beginning to the present day. The first investigations into the viability of capillary LC date back to the late 1970s, a decade after the pioneering efforts in HPLC. The drastically reduced column dimensions were required to counter the slow solute diffusion in liquids. There were numerous instrumental difficulties with sample introduction and detection in the picoliter or even femtoliter volumes. High-efficiency separations were needed in the analysis of complex biological mixtures. Miniaturization brought distinct advantages in spectroscopic and electrochemical detection. Since the 1980s, column technologies underwent significant changes: (a) from glass-drawn microcapillaries to slurry-packed, small-diameter fused silica columns; and (b) in microcapillaries packed alternatively with sub-2-µm particles or monoliths. The viability of LC-MS combination has dramatically promoted the use of small-diameter capillaries. Through "omics technologies", capillary LC/tandem MS accounts for most applications in proteomics, glycomics and metabolomics.

Analysis of eicosanoids by LC-MS/MS and GC-MS/MS: a historical retrospect and a discussion.

Eicosanoids are a large family that derives from arachidonic acid, i.e., eicosatetraenoic acid. Prominent members include prostaglandins, thromboxane and leukotrienes. They are biologically highly active lipid mediators and play multiple physiological roles. GC-MS/MS has played a pivotal role in the identification and quantification of eicosanoids in biological samples. This technology generated a solid knowledge of their analytical chemistry, biochemistry, physiology and pharmacology. Since about a decade, GC-MS and GC-MS/MS are increasingly displaced by the seemingly more simple, rapid and powerful LC-MS/MS in the area of instrumental analysis of physiological substances, drugs and their metabolites. In this article, we review and discuss LC-MS/MS methods published over the last decade from the perspective of the GC-MS/MS user. Our analysis revealed that the shift from the adult GC-MS/MS to the youthful emerging LC-MS/MS technology in eicosanoid analysis is associated with several important challenges. Known pitfalls and problematic issues discovered by eicosanoid pioneers by using GC-MS/MS are often ignored by LC-MS/MS users. Established reference values and intervals provided by GC-MS-based methods are not considered properly in developing and validating LC-MS/MS methods. Virtually, there is a belief in the unlimited capability of the LC-MS/MS technique in eicosanoid analysis, a thought that simulates analytical certainty. LC-MS/MS users should profit from the plethora of solid knowledge acquired from the use of GC-MS/MS in eicosanoid analysis in basic and clinical research.

Sampling and identification of natural dyes in historical maps and drawings by liquid chromatography with diode-array detection.

A simple and rapid liquid chromatographic with diode-array UV-vis spectrophotometric detection (HPLC-DAD) method for identification of natural dyes has been developed. Chromatographic retention of carminic acid, indigotin, crocetin, gambogic acid, alizarin and purpurin has been studied. The mobile phase consisted of 40 mM SDS-10 mM phosphate buffer solution (pH 2.3)-0.1% TFA (eluent A) and acetonitrile (eluent B) using a programmed gradient (5% B to 95% B). Analyses were carried out on a Phenomenex, Luna 5u NH2 100(a) column (250 mm x 4.60 mm i.d., 5 microm particle) and the operating conditions were: 0.6 ml min(-1) flow rate, 20 microl volume injection and 35 degrees C column temperature. Extracts of samples of natural dyes taken from historical maps belonging to The Royal Chancellery Archives in Granada were successfully analyzed using the proposed method including a new technique for sampling.

Csaba Horváth and preparative liquid chromatography.

Few chromatographers have been interested in furthering preparative liquid chromatography. The pioneers, Tswett, Kuhn and Lederer, A.J.P. Martin, Tiselius, isolated fractions but as an intermediate step in the analysis of their samples. The progress in electronics and sensors, and in their miniaturization has lead to the paradoxical situation that the analysts never see the transient pure fractions that their detector quantitates. Yet, over the last 25 years, preparative liquid chromatography has become an important industrial process for the separation, the extraction, and/or the purification of many pharmaceuticals or pharmaceutical intermediates, including pure enantiomers, purified peptides and proteins, compounds that are manufactured at the relatively large industrial scale of a few kilograms to several hundred tons per year. This development that has strongly affected the modem pharmaceutical industry is mainly due to the pioneering work of Csaba Horváth. His work in preparative HPLC was critical at both the practical and the theoretical levels. He was the first scientist in modem times to pay serious attention to the relationships between the curvature of the equilibrium isotherms, the competitive nature of nonlinear isotherms, and the chromatographic band profiles of complex mixtures. The thermodynamics of multi-component phase equilibria and mass transfer kinetics in chromatography attracted his interest and were the focus of ground-breaking contributions. He investigated displacement chromatography, an old method invented by Tiselius that Csaba was first to implement in HPLC. This choice was explained by the essential characteristic of displacement chromatography, in that it delivers fractions that can be far more concentrated than the feed. Remarkably, once the basics of nonlinear chromatography had been mastered in his group, most of the applications that were studied by his coworkers dealt with peptides of various sizes and with proteins. Thus, all the applications of preparative HPLC in the biotechnologies derive directly from Csaba's work. Although displacement did not pan out as a general method, the reasons are related more to practical constraints of the production of pharmaceuticals and to the long period of cheap energy that might be ending now. This report reviews Csaba's work in nonlinear chromatography.

The contributions of Csaba Horváth to liquid chromatography.

This article is not a biographic description of the life of Csaba Horváth, but an attempt to describe his most important contributions to liquid chromatography, as viewed by an author who himself started with HPLC in 1973. With the introduction of columns packed with rigid pellicular particles, which could withstand high pressures, the combination of fast separations with high efficiency was designated high pressure liquid chromatography about 35 years ago. The contribution of Horváth to the birth of modern LC was to imagine the potential for high-speed separations in LC by transferring ideas and technology from gas chromatography. From this time, his strong participation in understanding and describing the processes of separation science made him a leading scientist in fundamental studies of separation principles until his passing away in April 2004. In addition to being one of the forefathers of modern liquid chromatography, Csaba Horváth described both the ionic interactions and the hydrophobic interactions on ion exchangers as well as on reversed phase materials and developed a theoretical basis for understanding these processes. If one person should be mentioned as the inventor of ion-pair chromatography of organic compounds, of hydrophobic interaction chromatography, and of the theoretical basis for reversed phase chromatography, this person is Csaba Horváth. Throughout the last 30 years he also had a strong interest in studying proteins in separation processes, and in the last decade he made valuable contributions to capillary electrochromatography, particularly for separation of proteins on monolithic columns. For this author is difficult to find another person who has had a greater impact on liquid chromatography than Csaba Horváth.