Gas Chromatography Detectors - Detector Specifications > Page 2
The ideal GC detector should have a sensitivity of about 10-12 - 10-11 g/ml, and a linear dynamic range of about five orders of magnitude. It should have a catholic response, but be independent of the characteristics of the mobile phase. It should also be insensitive to changes in mobile phase flow rate through the sensor and also changes in temperature and pressure. No existing detector fulfills all these specifications but the FID come close to this ideal performance.
The subject of detector specifications has been touched upon in Principles and Practice of Chromatography and Gas Chromatography but will be treated here in detail. In order to evaluate a detector for use in GC, accurate performance criteria or specifications must be available to assess the pertinence of a particular detector for a given application. Such information is also necessary to permit a rational comparison with other detectors or detectors supplied by competitive manufacturers. The principle characteristics of a GC detector that will satisfy these requirements are as follows.
1. Dynamic Range
2. Response Index or Linearity
3. Linear Dynamic range
4. Detector Response
5. Detector Sensitivity or Minimum Detectable
6. System Dispersion
7. Sensor Dimensions
8. Detector Time Constant
9 Pressure Sensitivity
10. Flow Sensitivity
11. Operating Temperature Range