“…In practice, numerous types of packed columns possessing a high degree of reproducibility are commercially available. But simple procedures for preparing octadecylsilyl bonded stationary phase have been described (Kingston and Gerhart, 1976;Gilpin et al, 1975) and may be needed, for example, when packing a wide column for preparative-scale separations. Wehrli et al (1978) estimated that 80 % of current separations are done on octadecylsilyl bonded phase columns, commonly called C 18 columns (see Table 1.3).…”