| 摘要 |
<p>An apparatus and a method are described for forming a chemical modulation of a substance present in a fluid stream, which utilize a movable device (14), such as a movable heater (14), to induce changes in the retention of a chemical substance flowing through the modulator tube (27). The modulator tube (27) has an inlet, a first portion in communication with the inlet, a second portion in communication with the first portion, and an outlet in communication with the second portion. The method involves causing a chemical modulation comprising moving a retention alteration device (14) relative to a modulator tube (27).</p> |
