During a sabbatical with Prof JC Giddings in Utah in 1964, Knox was introduced to column liquid chromatography. Back home in 1969, he published a landmark paper with Mohammed Saleem, which suggested that the highest speed in liquid chromatography would be obtained by using 2 micron porous particles. In the 1970s Knox and his Edinburgh research group invented new micro-particulate packing materials for liquid chromatography, now marketed under the trade name Hypersil. He also invented porous graphitic carbon (now Hypercarb), creating an alternative packing material to silica gels for the industry.
