Justification for Column Selection and Care

The price of a column ( 200 to 800) may be viewed as relatively small compared to the initial, routine, and preventive maintenance costs of the instrument. In fact, a laboratory may find that the cost of a set of air and hydrogen gas cylinders of research-grade purity for FID (flame ionization detector) operation is far greater than the price of a single conventional capillary colunm Consequently, to derive maximum performance from a gas chromatographic system, the colunm should be carefully selected for an application, handled with care following the suggestions of its manufacturer, and installed as recommended in the user s instrument manual. 

The introduction of inert fused-silica capillary colunms in 1979 markedly changed the practice of gas chromatography, enabling high-resolution separations to be performed in most laboratories (1,2). Previously, such separations were achieved with reactive stainless steel columns and with glass colunms. After 1979, the use of packed colunms began to decline. A further decrease in the use of packed colunms occurred in 1983 with the arrival of the megabore capillary colunm of 

53-mm inner diameter (i.d.), which serves as a direct replacement for a packed colunm. These developments, in conjunction with the emergence of immobilized or cross-linked stationary phases tailored specifically for fused-silica capillary colunms and the overall improvements in colunm technology and affordability of mass spectrometry (MS), have been responsible for the wider acceptance of capillary GC. 

Trends. The results of a survey of 12 leading experts in gas chromatography appeared in 1989 and outlined their thoughts on projected trends in gas chromatographic column technology, including the future of packed columns versus capillary columns (11). Some responses of that panel are  

Packed columns are used for approximately 20% of gas chromatographic analyses. 

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