摘要 |
<p>Gas chromatographic methods and apparatus are disclosed whereby improved separation times and efficiency are achieved by provision of a time-programmable curvilinearly-shaped negative temperature gradient along the length of the chromatographic column (2). The gas phase sample traveling through the column (2) always passes to a column zone having a lower temperature than the previous column zone. Accordingly, upon elution, sample band-widths are compressed. Separation times may be decreased when compared to conventional isothermal or temperature programmed gas chromatography.</p> |