The use of GC/IR/MS for high-confidence identification of drugs.

We describe the use of a combined gas chromatographic/infrared/mass spectrometric system to identify some common, clinically important drugs. Sensitivity for the serially configured combined system is demonstrated to be in the low nanogram range for strong infrared-absorbing compounds. Linearity for cocaine in the infrared detector was shown to have a correlation coefficient of 0.9914. Vapor-phase infrared spectra are shown to be very reproducible, which is important in identifying drugs such as the barbiturates. Finally, the two completely independent principles of infrared and mass spectral detection lend significant confidence to the correct identification of the various drugs from a single injection of sample.