Abstract
We present a novel technique for analyzing volatile organic compounds in air samples using a solid adsorbent together with temperature‐programmed desorption and subsequent detection by membrane inlet mass spectrometry (TPD‐MIMS).
The new system has the advantage of a fast separation of compounds prior to the detection by MIMS. The gaseous sample is simply adsorbed on the adsorbent, which is then rapidly heated from 30 °C to 250 °C at a rate of 50 °C/min. Trapped organic compounds are released from the adsorbent into a helium stream at different temperatures depending on the strength of the interaction between the individual compound and the adsorbent. The helium stream carries the desorbed compounds to a membrane inlet (90 °C) equipped with a thin (25 μm) silicone membrane.
The thin membrane and the high temperature of the membrane inlet allows most volatile compounds to diffuse through the membrane into the mass spectrometer in a few seconds. In this fashion we could completely separate many similar volatile compounds, for example toluene from xylene and trichloroethene from tetrachloroethene.
Typical detection limits were at low or sub‐nanogram levels, the dynamic range was 3 orders of magnitude, and the analysis time for a mixture was about 3–4 minutes.
The new system has the advantage of a fast separation of compounds prior to the detection by MIMS. The gaseous sample is simply adsorbed on the adsorbent, which is then rapidly heated from 30 °C to 250 °C at a rate of 50 °C/min. Trapped organic compounds are released from the adsorbent into a helium stream at different temperatures depending on the strength of the interaction between the individual compound and the adsorbent. The helium stream carries the desorbed compounds to a membrane inlet (90 °C) equipped with a thin (25 μm) silicone membrane.
The thin membrane and the high temperature of the membrane inlet allows most volatile compounds to diffuse through the membrane into the mass spectrometer in a few seconds. In this fashion we could completely separate many similar volatile compounds, for example toluene from xylene and trichloroethene from tetrachloroethene.
Typical detection limits were at low or sub‐nanogram levels, the dynamic range was 3 orders of magnitude, and the analysis time for a mixture was about 3–4 minutes.
| Original language | English |
|---|---|
| Pages (from-to) | 773-778 |
| Journal | Rapid Communications in Mass Spectrometry |
| Volume | 12 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 1998 |
| MoE publication type | A1 Journal article-refereed |