Why is LC/MS/MS a better confirmation technique than GC/MS?
Gas chromatography/mass spectrometry (GC/MS) requires the drugs of interest to be put in the gas or vapor phase. This requires heating to very high temperatures. Sometimes it is additionally necessary to treat the sample with other chemicals (derivatizing agents) in order to get the drugs sufficiently able to be volatilized. This can result in loss of much of the analyte due to chemical instability at high temperatures. Thus much drug can be lost, and limits of detection are compromised. In addition, once volatilized into the gas phase, many drugs take a long time to go through the column of the gas chromatograph. Thus run times are long, and again much compound can be lost to thermal instability. In liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) the compounds travel underivatized through a chromatography column in solution at or near room temperature. Nothing has to be volatilized, there is no degradation due to heat, and the run time through the columns is very
