摘要 |
A method and apparatus for identifying and analyzing vapor elements, using a preconcentrator collector. The preconcentrator collector collects and preconcentrates chemical vapors to be detected and identified before chromatographic analysis using surface acoustic wave gas chromatograph (SAW/GC) technology. The preconcentrator collector is used in conjunction with a sensor in an SAW/GC detector in the apparatus. A physical parameter associated with the sensor changes in a defined manner upon exposure of the sensor to an unknown vapor, permitting identification of the individual vapor elements. The preconcentrator collector of the invention includes a body portion having an inlet and an outlet, and a stack of collector plates disposed in the body portion. The collector plates are made of a material that is easily micromachinable and easily cleanable, such as silicon, silica or fused quartz. The outlet of the body portion is connectable to a sampling pump for taking a sample of ambient air into the body portion through the inlet. After the sample is taken, the collector plates trap the chemical vapors in the sample of ambient air and non-trapped vapors exit through the outlet. By using the preconcentrator collector, the present invention achieves more specificity and selectivity simultaneously with high sensitivity. |