A new approach for drug screening and detection in urine has been developed and studied. Fast gas chromatography/mass spectrometry (GC/MS) in combination with supersonic molecular beams was applied, employing hyperthernial surface ionization (HSI). Fast GC/MS (less than three minutes) screening of drugs in an untreated urine sample, at a detection limit of less than 100 ppb is shown. For this purpose, a new technique of "in-needle vaporization injection" (INVI) was developed for the introduction of untreated urine into the GC injector, leading to a minimal amount of salt and residue deposit on the GC liner and column. This new technique is compared with conventional syringe injection. Hyperthermal surface ionization of drugs is discussed in terms of ionization efficiency, selectivity and mass spectral appearance.
- Hyperthermal surface ionization