## 3 Results and Discussion
Thus, our group concludes that the three characteristic peaks, ([M+H]\({}^{+}\) and the peaks from the \(\alpha\)-cleavage and \(\beta\)-cleavage processes) are very unique and provide useful information in identifying phenethylamines and tryptamines in actual forensic cases based on the ESI/MS or MALDI/TOFMS methods. Although a direct sample injection is possible based on some LC-ESI/MS methods, which would be an ideal method for rapid screening, thus far, such studies also can be performed by means of MALDI/TOFMS since the sample substrate used in MALDI/TOFMS can be much easily inserted and changed. Our group selected MALDI/TOFMS as the rapid screening tool for the following studies, including actual clandestine tablet, hair and urine samples. Figure 3: EI/MS; ESI/MS; and MALDI/TOFMS spectra of (**a**) 2C-T-7, (**b**) 3,4-MBMB and (**c**) DET (each sample, 0.1 mg mL\({}^{-1}\) methanol), respectively. The major fragments of CHCA are indicated as “**”. **  
Figure 2: A general schematic outline for \(\alpha\)-cleavage and \(\beta\)-cleavage when the EI/MS (electron ionization–mass spectrometry), ESI/MS (electrospray ionization/mass spectrometry) and MALDI/TOFMS (matrix assisted laser desorption/time-of-flight mass spectrometry) methods were used, respectively. \(N\),\(N\)-dimethylryptamine (DMT; Mw: 188) was selected as the model compound. Figure 4a shows a typical mass spectrum obtained by the MALDI/TOFMS method from an actual clandestine tablet, which was seized from the illicit market. CHCA and Nd:YAG laser (355 nm) were used as the matrix and excitation source, respectively. As can be seen from the mass spectrum in Figure 4a, the ion peaks at \(m/z=194\) and \(m/z=58/163\) correspond to the protonated parent ion and the fragments from \(\beta\)-cleavage and \(\alpha\)-cleavage, respectively, indicating that the tablet could contain 3,4-MDMA. The ion peaks at \(m/z=150\) and \(m/z=58/119\) correspond to the protonated parent ion and the fragments from the \(\beta\)-/\(\alpha\)-cleavage, respectively, indicating that the tablet also contains methamphetamine. Furthermore, the ion peaks belong to norepinephrine (\(m/z=152\)) and ephedrine (\(m/z=166\)), raw materials for the synthesis of methamphetamine. The fragment (\(m/z=136\)) from \(\alpha\)-cleavage also was found. Peaks corresponding to caffeine and ketamine also were found, showing that this was a tablet with multiple components. Herein, it should be noted that 3,4-BDB (3,4-benzodioxol-5-yl-2-butylamine) can provide similar pattern with 3,4-MDMA. Hence, in this case, the clandestine tablet should be examined in detail if ion peaks at \(m/z=194\) and \(m/z=58\) were found. In other words, a rapid screening method is important and useful for saving time. Figure 4b shows a typical MALDI-TOF mass spectrum for a 3,4-MDMA spiked hair (black color). The inset shows a 3,4-MDMA spiked white hair. The results indicate that the MALDI/TOFMS method is also useful for rapid screening of hair samples without any pretreatment; however, a black hair absorbs laser emission better than a white hair. Finally, a 0.01 mg mL\({}^{-1}\) DMT standard was spiked to a blank urine sample. The findings show that ion peaks at \(m/z=189\) and \(m/z=58\) can be found (data not shown). The limit of detection of DMT in urine is about 0.001 mg mL\({}^{-1}\). Instead, Figure 4c shows the mass spectrum of a LSD (a tertiary amine with a tryptamine-like structure) spiked urine sample, since LSD is very difficult to detect by GC/MS without derivatization process. As seen in the mass spectrum, several peaks appear, but the peak of the spiked LSD urine sample (0.001 mg mL\({}^{-1}\)) can be clearly observed. The matrix used was 2,5-DHB, since it works better than CHCA. The inset shows the same urine sample before spiking. In Taiwan, if the concentration of amphetamines or related metabolites exceeds 0.0005 g mL\({}^{-1}\), a suspect is judged guilty. The method proposed here provides sufficient sensitivity to permit identification at such a low level of LSD.