Fast temperature programming on a stainless-steel narrow-bore capillary column by direct resistive heating for fast gas chromatography.

A direct resistive-heating fast temperature programming device for fast gas chromatography was designed and evaluated. A stainless-steel (SS) capillary column acted both as a separation column and as a heating element. A fast temperature controller with the deviation derivative proportional-integral-derivative (DDPID) control algorithm, which was suitable for ramp control using ramp-to-setpoint function, was used to facilitate the fast pulse heating. The SS resistive-heating column can generate linear temperature ramps up to 10 degrees C/s and can re-equilibrium from 250 degrees C down to 50 degrees C within 30s. With n-alkanes as the test analytes, the relative standard deviations (RSDs) of retention time were between 0.19 and 0.59% and the RSDs of their peak areas were less than 4% for all but one. The results indicated that this technique could be used for both qualitative and quantitative analysis. Phenolic and nitroaromatic compounds were also analyzed by using the SS resistive-heated system. The combination of a short narrow-bore SS column and rapid heating rates provides sufficient separation efficiency for relatively simple mixtures at drastically reduced analysis time. The total analysis time including equilibration time was less than 2 min for all test mixtures in this study.