## 3 Results and Discussion
5 were detected in the negative-ion mode, while the other 11 compounds were detected in the positive-ion mode. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**Conc.**} & \multicolumn{2}{c}{**Recovery**} & \multicolumn{2}{c}{**Intra-Day**} & \multicolumn{2}{c}{**Inter-Day**} \\ \cline{3-8}  & & \multirow{2}{*}{**Mean (\%)**} & \multirow{2}{*}{**RSD (\%)**} & \multirow{2}{*}{**Accuracy (\%)**} & \multicolumn{2}{c}{**Precision**} & \multirow{2}{*}{**Accuracy (\%)**} & \multirow{2}{*}{**Precision**} \\  & & & & & & **(RSD\%)** & & **(RSD\%)** \\ \hline Solvent Red 24 & 0.54 & 104.54 & 2.07 & 103.76 & 9.23 & 101.85 & 6.22 \\  & 5.40 & 104.59 & 1.39 & 99.99 & 0.70 & 98.85 & 1.46 \\  & 27.00 & 103.45 & 0.55 & 102.09 & 0.08 & 100.84 & 1.15 \\ \hline Solvent Yellow 1 & 0.03 & 93.49 & 3.04 & 84.91 & 9.99 & 91.57 & 6.39 \\  & 0.30 & 103.12 & 1.63 & 102.98 & 0.38 & 101.53 & 1.46 \\  & 1.50 & 101.65 & 1.41 & 102.38 & 0.25 & 100.71 & 1.48 \\ \hline Solvent Yellow 3 & 0.05 & 99.75 & 2.16 & 83.21 & 8.62 & 91.13 & 8.07 \\  & 0.50 & 100.24 & 0.70 & 102.66 & 0.49 & 101.19 & 1.50 \\  & 2.50 & 102.14 & 1.15 & 102.48 & 0.29 & 100.78 & 1.51 \\ \hline \end{tabular}  
* Conc., concentration; RSD, relative standard deviation.  
\end{table} 
Table 4: _Cont._ \begin{table}
\begin{tabular}{c c c c c c} \hline
**Compound** & **Chemical Formula** & **Ion Mode** & **Precursor Ion (\(m/z\))** & **CV (V)** & **Product Ion (\(m/z\))** & **CE (V)** \\ \hline Basic Blue 26 & C\({}_{33}\)H\({}_{32}\)ClN\({}_{3}\) & + & 470.42 & 15 & 349.30 * & 35 \\  & & & & 454.38 & 40 \\  & & & & 333.28 & 50 \\ \hline Basic Red 2 & C\({}_{20}\)H\({}_{19}\)N\({}_{4}\)Cl & + & 315.32 & 15 & 299.30 * & 40 \\  & & & & 210.24 & 50 \\  & & & & 237.26 & 40 \\ \hline Basic Yellow 28 & C\({}_{21}\)H\({}_{27}\)N\({}_{3}\)O\({}_{5}\)S & + & 322.34 & 15 & 160.24 * & 20 \\  & & & & 136.18 & 25 \\ \hline Disperse Brown 1 & C\({}_{16}\)H\({}_{15}\)Cl\({}_{3}\)N\({}_{4}\)O\({}_{4}\) & + & 433.25 & 15 & 197.25 * & 30 \\  & & & & 153.23 & 35 \\  & & & & 357.19 & 30 \\ \hline Disperse Orange 3 & C\({}_{12}\)H\({}_{10}\)N\({}_{4}\)O\({}_{2}\) & + & 243.27 & 15 & 122.18 * & 15 \\  & & & & & 75.22 & 30 \\  & & & & 92.22 & 25 \\ \hline Disperse Yellow 3 & C\({}_{15}\)H\({}_{15}\)N\({}_{3}\)O\({}_{2}\) & - & 268.28 & 15 & 134.23 * & 20 \\  & & & & 92.21 & 25 \\ \hline HC Blue No. 2 & C\({}_{12}\)H\({}_{19}\)N\({}_{3}\)O\({}_{5}\) & + & 286.29 & 15 & 210.29 * & 25 \\  & & & & 241.31 & 20 \\ \hline HC Yellow No. 5 & C\({}_{8}\)H\({}_{11}\)N\({}_{3}\)O\({}_{3}\) & - & 196.21 & 15 & 166.23 * & 15 \\  & & & & 151.19 & 20 \\  & & & & 137.22 & 20 \\ \hline Solvent Orange 4 & C\({}_{13}\)H\({}_{14}\)N\({}_{4}\) & + & 227.33 & 15 & 134.27 * & 30 \\  & & & & 120.24 & 30 \\ \hline Solvent Orange 7 & C\({}_{18}\)H\({}_{16}\)N\({}_{2}\)O & + & 277.31 & 15 & 121.28 * & 20 \\  & & & & 156.24 & 15 \\ \hline \end{tabular}  
* \end{table} 
Table 5: LC-MS/MS MRM transitions of 13 illegal synthetic colorants. The 120 purchased samples were classified into tattoo lipsticks (40), tattoo eyebrows (41), and hair tints (39). Figure 3 shows the results of illegal pigment detection by HPLC-DAD, revealing that three peaks with retention times and UV spectra matching those of Basic Red 2, Basic Yellow 28, and Basic Blue 26 were detected in a tattoo eyebrow product. The contents of these three components (HPLC-DAD) were determined as 0.53 mg/g (Basic Red 2), 31.50 mg/g (Basic Yellow 28), and 0.33 mg/g (Basic Blue 26). The identities of these three compounds were confirmed by positive mode using LC-MS/MS. The total ion chromatogram (Figure 3) of the tattoo eyebrow sample showed peaks at 5.13, 5.97, and 7.62 min corresponding to the peaks for Basic Red 2, Basic Yellow 28, and Basic Blue 26 standards, respectively. The precursor and product ions of these three colorants were the same as those of the respective standards. Basic Red 2 showed a precursor ion at \(m/z\) 315.32 and product ions at \(m/z\) 299.30, 210.24, and 237.26.