## 3 Results and Discussion
### PTR-ToF-MS: Determination of Volatile Compounds from Spirulina
Even in that case, this investigation  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Component**} & \multirow{2}{*}{_m/z_} & **Chemical** & **Teantative Identification** & **Average** & **SD** & **\%** \\ \hline
1 & 27.022 & C\({}_{2}\)H\({}_{3}\)\({}^{*}\) & Acetylene & 34.99 & 8.47 & 2.33 \\
2 & 33.033 & CH\({}_{5}\)O\({}^{*}\) & Methanol & 241.52 & 37.47 & 16.08 \\
3 & 41.038 & C\({}_{3}\)H\({}_{5}\)\({}^{*}\) & Alkylic fragment & 63.76 & 14.62 & 4.24 \\
4 & 43.018 & C\({}_{3}\)H\({}_{5}\)O\({}^{*}\) & Aldehyde fragment & 123.58 & 12.59 & 8.23 \\
5 & 45.033 & C\({}_{2}\)H\({}_{3}\)O\({}^{*}\) & Acetaldehyde & 178.26 & 37.18 & 11.87 \\
6 & 47.049 & C\({}_{2}\)H\({}_{3}\)O\({}^{*}\) & Ethanol & 18.83 & 1.5 & 1.25 \\
7 & 49.011 & CH\({}_{5}\)S\({}^{*}\) & S Compound (methanindiol) & 9.48 & 0.5 & 0.63 \\
8 & 55.054 & C\({}_{4}\)H\({}_{5}\)\({}^{*}\) & Fragment & 24.35 & 2.78 & 1.62 \\
9 & 57.069 & C\({}_{4}\)H\({}_{5}\)O\({}^{*}\) & Alcohol fragment & 40.32 & 9.73 & 2.68 \\
10 & 59.049 & C\({}_{3}\)H\({}_{5}\)O\({}^{*}\) & Propanal & 142.27 & 24.85 & 9.47 \\
11 & 61.028 & C\({}_{3}\)H\({}_{5}\)O\({}^{*}\) & Acetic acid & 414.32 & 44.92 & 27.58 \\
12 & 67.054 & C\({}_{5}\)H\({}_{5}\)O\({}^{*}\) & Fragment & 2.55 & 0.32 & 0.17 \\
13 & 69.069 & C\({}_{4}\)H\({}_{5}\) & 1,3-Pentadiene & 14.95 & 0.97 & 1.00 \\
14 & 71.049 & C\({}_{4}\)H\({}_{5}\)O\({}^{*}\) & Butenal & 8.63 & 0.69 & 0.57 \\
15 & 73.064 & C\({}_{4}\)H\({}_{5}\)O\({}^{*}\) & Propanal\_methyl & 24.53 & 3.9 & 1.63 \\
16 & 75.044 & C\({}_{3}\)H\({}_{5}\)O\({}^{*}\) & Acetol & 1.6 & 0.21 & 0.11 \\
17 & 79.049 & C\({}_{6}\)H\({}_{5}\)F\({}^{*}\) & Benzene & 3.59 & 0.43 & 0.24 \\
18 & 80.05 & C\({}_{6}\)H\({}_{5}\)N\({}^{*}\) & Pryazyne & 6.59 & 2.24 & 0.44 \\
19 & 81.073 & C\({}_{6}\)H\({}_{5}\) & C6 fragments & 4.31 & 0.33 & 0.29 \\
20 & 83.083 & C\({}_{6}\)H\({}_{5}\)O\({}^{*}\) & 2-Methylfuran & 7.41 & 2.69 & 0.49 \\
21 & 85.06 & C\({}_{6}\)H\({}_{5}\)O\({}^{*}\) & 1-Penten-3-one/2-Pental & 4.75 & 1.95 & 0.32 \\
22 & 87.044 & C\({}_{4}\)H\({}_{5}\)O\({}_{5}\)\({}^{*}\) & Diacetyl! & 4.41 & 1.06 & 0.29 \\
23 & 87.091 & C\({}_{4}\)H\({}_{5}\)N\({}^{*}\) & Piperazine & 11.79 & 2.85 & 0.78 \\
24 & 89.059 & C\({}_{4}\)H\({}_{5}\)O\({}_{5}\) & Ethyl acetate/Butanoic acid & 4.87 & 0.76 & 0.32 \\
25 & 91.057 & C\({}_{4}\)H\({}_{5}\)S\({}^{*}\) & Butanehiol & 5.41 & 0.96 & 0.36 \\
26 & 95.061 & C\({}_{5}\)H\({}_{5}\)N\({}^{*}\) & Pyrazine, methyl- & 22.14 & 3.51 & 1.47 \\
27 & 97.085 & C\({}_{6}\)H\({}_{5}\)O\({}^{*}\) & Furan, 2-ethyl & 3.47 & 0.28 & 0.23 \\
28 & 103.075 & C\({}_{6}\)H\({}_{1}\)O\({}^{*}\) & Cyclopentanedecki & 1.65 & 0.45 & 0.11 \\
29 & 107.049 & C\({}_{3}\)H\({}_{5}\)O\({}^{*}\) & Benzaldehyde & 4.48 & 0.25 & 0.30 \\
30 & 109.076 & C\({}_{6}\)H\({}_{5}\)N\({}^{*}\) & 2,6-Dimethylpyrazine & 29.17 & 2.3 & 1.94 \\
31 & 111.1 & C\({}_{6}\)H\({}_{5}\)\({}^{*}\) & 1-Methylcycloheptene & 2.74 & 0.22 & 0.18 \\
32 & 113.1 & C\({}_{6}\)H\({}_{5}\)O\({}^{*}\) & 3-methylcyclopentanedione & 2.35 & 0.87 & 0.16 \\
33 & 115.1 & C\({}_{7}\)H\({}_{5}\)O\({}^{*}\) & Hepanal & 1.78 & 0.54 & 0.12 \\
34 & 123.105 & C\({}_{8}\)H\({}_{1}\)O\({}^{*}\) & Dimethylphenyl/Ethylphenol & 5.01 & 1.43 & 0.33 \\
35 & 125.106 & C\({}_{8}\)H\({}_{1}\)O\({}^{*}\) & (2)-1,5-ocademia-3-one & 1.83 & 0.75 & 0.12 \\
36 & 127.111 & C\({}_{8}\)H\({}_{5}\)O\({}^{*}\) & 1,5-Octadian 3-ol & 2.36 & 0.95 & 0.16 \\
37 & 137.122 & C\({}_{4}\)H\({}_{5}\)O\({}^{*}\) & Unknown & 7.24 & 1.54 & 0.48 \\
38 & 139.211 & C\({}_{6}\)H\({}_{5}\)O\({}^{*}\) & Isophorone/Furan, 2-Pentyl- & 8.39 & 1.48 & 0.56 \\
39 & 151.111 & C\({}_{10}\)H\({}_{5}\)O\({}^{*}\) & Safarnal & 3.57 & 0.87 & 0.24 \\
40 & 153.134 & C\({}_technique proved to be particularly useful and adequate for identifying a high number of low-molecular-weight compounds characterizing the matrix under examination.