Criteria for the identification of compounds by liquid chromatography–mass spectrometry and liquid chromatography–multiple mass spectrometry in forensic toxicology and doping analysis Review Article

In contrast to GC–MS, many factors are influencing mass spectra of organic compounds when analyzed by LC–MS. In-source or transport collision-induced dissociation by electrospray ionization or atmospheric pressure chemical ionization demonstrate the need for experimental condition standardization when building-up a library of reference spectra. Magnetic sector, quadrupole, ion trap or time-of-flight filters placed on single or multiple mass spectrometry instruments coupled with HPLC deliver unique mass intensities pattern from the same molecules that are most often not readily comparable between each other. This makes it very difficult or even impossible to rely on any collections of reference data whatever comparison algorithm is applied for library search or manual comparison when full confirmation of identity is required. Typical areas of expertise are very sensitive to sound and complete package procedures to withstand administrative or court’s scrutiny. In this paper, this problem is referred to the specific field of forensic toxicology and doping control in sports. Several official guidelines have been released recently and await confrontation with concrete cases. Closely related areas like residues in living animals and meat products are regulating these aspects with detailed procedures. Basically, they all propose the accumulation of a finite quantity of information about the unknown molecule and the reference substance. These confirmatory packages are briefly exposed, compared and evaluated for their future application to the newest LC–MS techniques that are more frequently used within these critical fields of expertise.