Nuclear quadrupole resonance detection of drugs or explosives

摘要

A method of Nuclear Quadrupole Resonance testing a sample containing a given species of quadrupolar nucleus, the sample being subjected to an inhomogeneous distribution of an extrinsic parameter, the parameter having a variation over the sample over a particular range, comprises applying excitation to the sample at a plurality of different excitation frequencies to excite nuclear quadrupole resonance, such frequencies falling within the resonance frequency range for the nucleus corresponding to the range of the extrinsic parameter, and detecting the resonance response signal. The RF pulses may be phase-modulated. Echoes or FIDs may be detected. A temperature-insensitive resonance frequency may be used. IMAGE