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 split sampling technique on eight experimental variables affecting the introduction of large sample volumes in capillary GC was evaluated. The simplex method was used to improve the sensitivity of the analysis significantly by optimization of the operating conditions, namely sample volume, flow-rate during sampling, initial PTV temperature, length of the adsorbent bed, nature of the trapping material used in the glass liner, speed of sample introduction, elimination volume and solvent elimination temperature. With this method, reliable determinations of several volatile components at sub-ppb concentrations were obtained using a flame ionization detector, without the need for prior enrichment of the sample.