The Basic Column Chromatograph A chromatograph consists of five basic units and these units, although possibly designed differently for different systems, are essential for all types of chromatograph, including both gas and liquid chromatographs. The layout of all the five essential units is shown in figure 24. They consists of a mobile phase supply, a sampling system, a column and column oven including a temperature controller and temperature programming system. The temperature controller and

majority of the added devices and techniques were suggested or describe in the first three international symposia on gas chromatography held in 1956, 1958 and 1960. These symposia, initially organized by the 'British Institute of Petroleum' have been held every two years ever since 1956 and the meetings have remained the major stimulus for developing the technique and extending its capabilities. However, the majority of the techniques and devices that have been incorporated in the modern chromatograph, were described, reported, or discussed in the first triad of symposia.   The layout of the modern gas chromatograph is shown as a block diagram in figure 1.  

The Basic Liquid Chromatograph The basic liquid chromatograph consists of six basic units. The mobile phase supply system, the pump and programmer, the sample valve, the column, the detector and finally a means of presenting and processing the results. A block diagram of the basic liquid chromatograph is shown in figure 1 Figure 1. The Basic Liquid Chromatograph

The Combination of the Gas Chromatograph with Other Spectroscopic Systems   Unfortunately the resolution of the MS 12 was little better than 1 mass unit and so the actual molecular formula of the eluted peak could not be determined by calculation but only by conventional analytical procedures. However, unit mass resolution was often inadequate for accurate spectra interpretation, and further information, such as the presence of functional groups, was found necessary for reliable structure elucidation.   The

Apparatus for use with Capillary Columns   The apparatus used specifically with capillary columns differs very little from the general gas chromatograph. Capillary columns require particular sampling systems and also have a more restricted range of suitable detectors than those usable with packed columns, but other than that, the capillary gas chromatograph is identical to that used with packed columns. A diagram of the lay out of a gas chromatograph used specifically with capillary columns is shown in figure 5.   Gas Supply   The gas supply incudes the usual gas tank, reducing valve and flow controller; the pressures

Introduction Chromatography, in one of its several forms, is the most commonly used procedure in contemporary chemical analysis and the first configuration of chromatography equipment to be produced in a single composite unit and made commercially available was the gas chromatograph. Gas chromatography was invented by A. J. P. Martin who, with R. L. M. Synge, suggested its possibility in a paper on liquid chromatography published in 1941 (1). Martin and Synge recommended that the liquid mobile phase used in liquid chromatography could be replaced by a suitable gas. The basis for this recommendation was that, due to much higher diffusivities of solutes in gases compared with liquids, the equilibrium processes involved in a chromatographic process (see