VARIABLES AFFECTING THE INTRODUCTION OF LARGE-SAMPLE VOLUMES IN CAPILLARY GAS-CHROMATOGRAPHY USING A PROGRAMMED-TEMPERATURE VAPORIZER

The dependence of the programmed-temperature vaporizer (PTV) solvent s plit sampling technique on eight experimental variables affecting the introduction of large sample volumes in capillary GC was evaluated. Th e simplex method was used to improve the sensitivity of the analysis s ignificantly by optimization of the operating conditions, namely sampl e volume, flow-rate during sampling, initial PTV temperature, length o f the adsorbent bed, nature of the trapping material used in the glass liner, speed of sample introduction, elimination volume and solvent e limination temperature. With this method, reliable determinations of s everal volatile components at sub-ppb concentrations were obtained usi ng a flame ionization detector, without the need for prior enrichment of the sample.