Signal selective amplification: A solution for an improved detection of amphetamines with QCL equipped portable GC-IRAS spectrometers

In this article we are presenting a signal selective amplification method that was used for improving the automatic detection of amphetamines based on their infrared absorptions recorded in the narrow spectral window in which the QCL source of a new portable GC-IRAS spectrometer is emitting (1550-1330 cm
^-1
). The expert system developed for class identity assignment is based on Principal Component Analysis (PCA) and distinguishes the amphetamines according to their toxic effect (stimulant and hallucinogenic amphetamines). The detection efficiency and accuracy was evaluated by using Cluster Analysis (CA).