Mass spectrometric detection base peak chromatograms

We convert them to their iso thiocyanates, just by addition of carbon disulfide to the extract (8). Fig. 10 shows the mass spectrum of the derivative of mescaline. The fragmentation is very simple. The molecular ion at m/e 253 and the base peak at m/e 181 contain practically all the spectrometric information. Fig. 11 shows a gas chromatogram of 13 pg of mescaline after conversion to the mustard oil, recorded with mass specific detection of the molecular ion. This is a good example of the sensitivity of the method. 

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