A general system for the automation of a backflush equipped gas chromatograph and its application in the determination of fluoride in plasma and faeces.

A fully automated system is described in which a gas chromatograph equipped with a backflush valve is automatically operated under the control of a specially designed timer unit. The system requires minimum data acquisition due to the selection of the signals to be integrated while waste of recorder paper is also avoided. It has the capability of unattended operation of fifty samples which--in the case of fluoride determination--are chromatographed in about four hours.