A review of HPLC column packing technology

Congratulations on American Laboratory's 35th anniversary. The history of HPLC and its column technology parallels the history of American Laboratory. The meeting that comes to mind in which HPLC finally had its reckoning was the Fifth Symposium on the Advances in Chromatography, Las Vegas, NV, in 1969. Up until that time, column liquid chromatography was not part of any symposium, but was merely a technique practiced by a few organic chemists purifying their synthetic mixtures. Indeed, most of the technical papers at this 1969 Zlatkis Symposium (as it was then nicknamed, having been founded by the late Albert Zlatkis, Chemistry Professor at the University of Houston, TX) were gas chromatography presentations with a session or two devoted to this new technique. However, the discussion sessions were where the action took place, such as lively forums on columns and detector technology. Most of those notables present were from the GC ranks who discovered a fertile new ground to explore. Even then, GC had achieved a certain level of maturity in terms of the theory and basic studies of band broadening, stationary phase technology, and injection techniques, although further developments in capillary technology were to come in the 1970s. After that pivotal meeting, most of the fundamental chromatography investigators turned their attention from GC to HPLC. The column has always played a major role in the progress of HPLC. The major developments in the late 1960s that turned HPLC from being a stow, relatively insensitive separation technique were 1) the flow-through low-volume UV detector and 2) pellicular packings (also known as superficially porous or porous layer bead packings). The intent of this paper is to focus on the development of HPLC column packings from the early days until the present day. Since this is such a wide area, the article will center mainly on developments in particle morphology and column design. Modern column technologies that make HPLC one of the major tools of practicing chemists will then be discussed.