This volume represents the proceedings of an international symposium on sample preparation, held at the University of Surrey, and jointly organised by the Chromatographic Society and the Robens Institute. The Chromatographic Society is the only international organisation devoted to the promotion of, and the exchange of information on, all aspects of chromatography and related techniques. With the introduction of gas chromatography in 1952, the Hydrocarbon Chemistry Panel of the Hydrocarbon Research Group of the Institute of Petroleum, recognising the potential of this new technique, set up a Committee under Dr S.F. Birch to organise a symposium on "Vapor Phase Chromatography" which was held in London in June 1956. Almost 400 delegates attended this meeting and success exceeded all expectation. It was to afford discussion of immediately apparent that there was a need for an organised forum development and application of the method and, by the end of the year, the Gas Chromatog­ raphy Discussion Group had been formed under the Chairmanship of Dr A.T. James with D.H. Desty as Secretary. Membership of this Group was originally by invitation only, but in deference to popular demand, the Group was opened to all willing to pay the modest sub­ scription of one guinea and in 1957 A.J.P. Martin, Nobel Laureate, was elected inaugural Chairman of the newly-expanded Discussion Group.