Courtesy of Supelco Inc.
Figure 23. The Separation of a PIANO Standard Mixture
The Nitrogen Phosphorus Detector (NPD)
The nitrogen phosphorus detector (NPD), is a highly sensitive but specific detector and evolved directly from the FID. It gives a strong response to organic compounds containing nitrogen and/or phosphorus. Although it appears to function in a very similar manner to the FID, in fact, it operates on an entirely different principle. A diagram of an NP detector is shown in figure 24.
Figure 24. The Nitrogen Phosphorus Detector