LC/MS/MS has emerged in the clinical laboratory only within the past 10 or 15 years. It has a number of advantages over GC/MS:
- Sample pre-treatment or extraction is reduced or even eliminated.
- There is usually no need to derivatize the analyte to make it more volatile and less polar. Polar compounds can easily be analyzed by LC/MS/MS.
- LC/MS/MS also offers a much higher degree of sensitivity and specificity.
However, GC/MS does have some advantages over LC/MS/MS. The price tag is number one; a GC/MS can cost a fraction of an LC/MS/MS system. The GC/MS also gives more structural information due to the high degree of fragmentation seen in electron impact ionization. Therefore, GC/MS identification of unknown analytes by searching through a spectral database or library is only currently practical with GC/MS.