Optically heated analyte desorber for gas chromatography analysis

摘要

Analytes are rapidly desorbed from a carbonaceous sorbent powder with improved quantitation and reduced analyte re-adsorption, thermal degradation, and rearrangement. The sample is distributed in a thin layer onto a desorption surface within a chamber. The layer can be a monolayer. Heating light irradiates the sample through a window, directly and rapidly heating the sample while the desorbed analytes diffuse into a vacuum or are removed by a carrier gas. Finally, the sorbent is flushed from the chamber by a transport gas. The desorption surface can be an inner surface of the window, or a surface of a porous frit that divides the chamber into two sections. The frit can be stainless steel or glass. The carrier gas can be helium, argon, or carbon dioxide. The light source can be a tungsten halogen lamp. A heater can control the chamber temperature according to a heating profile.

主权项

1. A system for rapidly desorbing analytes from a carbonaceous sorbent powder for introduction into a gas chromatograph, the system comprising:
a sealed desorption chamber; a desorption surface within the desorption chamber onto which the sorbent powder can be deposited, the sorbent powder having analytes adsorbed thereupon; a transport gas system configured to transport the sorbent powder with a transport gas into the desorption chamber and to deposit the sorbent powder onto the desorption surface as a substantially uniform layer of sorbent powder granules, the transport gas system being further configured to remove the sorbent powder from the desorption chamber after desorption of the analytes therefrom; a heating light source located outside of the desorption chamber; a window included in a wall of the deposition chamber and positioned so as to allow light from the heating light source to uniformly illuminate all of the uniform monolayer of sorbent powder, absorption of the heating light by the sorbent powder causing desorption of the analytes therefrom; and an analyte removal system configured to transport desorbed analytes away from the sorbent powder out of the desorption chamber, and into the gas chromatograph, said analyte removal system being distinct from said transport gas system.