SIMPLEX OPTIMIZATION OF THE ALTERNATING-CURRENT PLASMA DETECTOR FOR GAS-CHROMATOGRAPHY

Several operating parameters for the alternating-current plasma detector for gas chromatography were optimized on the basis of maximization of the peak area response of the detector towards ethylmercury(II)chloride by the modified simplex algorithm. The parameters included in the study were the ac power output, helium make-up flow rate, column flow rate, PMT voltage, and slit width. Univariant values of the optimum were equivalent to most simplex optimum values in this study. Detector evaluation was based on the new optimized response and a new detector interface design and is compared to previous values obtained for this detector. Lower detection limits of 1.10 pg/s were realized, coupled with a relative standard deviation between 1 and 5%. Detector linearity extended over three orders of magnitude.