IMPLEMENTATION OF THE CHEMICAL-REACTION INTERFACE MASS-SPECTROMETRY TECHNIQUE ON A HEWLETT-PACKARD MASS-SELECTIVE DETECTOR

A microwave-powered chemical reaction interface has been installed in a Hewlett-Packard gas chromatograph-mass spectrometer (GC-MS) system ( 5890 II gas chromatograph-5971 mass-selective detector). The technical details and optimization strategies are discussed. The evaluation of this new setup is presented, showing detection limits of 1 ng of C--13 , N--15, and Cl-containing compounds with signal-to-noise ratios great er than or equal to 3. Selective detection was evaluated with a urine sample from a dog dosed with N-15(3)-midazolam that had been previousl y analyzed by using a differentially pumped research-level quadrupole mass spectrometer. The results show that the detection of N-15 and Cl remains highly selective and the mass-selective detector gives compara ble sensitivity to the larger instrument when the latter is operating over a conventional mass range. The capability for chemical reaction i nterface mass spectrometry can be easily accomplished with an inexpens ive GC-MS system.