number Compound name Characteristic ion (m/z) Retention time (min) Relative abundance (%)
1 1-Methyl- cyclopentene 67 4.756 0.31
2 Benzene 77 5.221 13.89
3 Toluene 91 6.791 9.39
4 Ethylbenzene 91 8.972 2.31
5 m/p-Xylene 91 9.164 13.49
6 o-Xylene 91 10.004 5.19
7 Styrene 104 10.281 0.84
8 (1-methylethyl)-benzene 120 10.597 0.23
9 Propyl benzene 91 11.495 0.79
10 1-Ethyl-3-methyl benzene 120 11.799 6.30
11 1,3,5-Trimethyl benzene 105 12.031 2.43
12 1-Ethyl-2-methyl benzene 120 12.534 1.57
13 1,2,3-Trimethyl- benzene 105 12.939 8.49
14 1-Methyl-2-(1-methylethyl)- benzene 119 13.44 0.29
15 1,2,4-Trimethyl- benzene 105 14.126 2.11
16 1-Methyl-3-propyl- benzene 105 14.42 1.68
17  (1-Methylpropyl)- benzene 173 14.575 0.51
18 2-Ethyl-1,4-dimethyl- benzene 119 14.734 1.79
19 Indane 117 14.979 1.83
20 1,4-Dichloro- benzenea 146 15.284 2.26
21 2-Ethyl-3,4-dimethyl- benzene 119 15.426 1.98
22 2-Ethyl-1,3-ldimethyl- benzene 119 15.745 1.95
23 2-Butenyl- benzene 117 16.062 0.56
24 1-Ethenyl-3-ethyl- benzene 117 16.295 1.21
25 2-Ethyl-1,4-dimethyl- benzene 119 16.661 0.39
26 1,2,4,5-Tetramethyl- benzene 134 16.829 1.30
27 1,2,3,5-Tetramethyl- benzene 134 17.07 1.93
28 (1,1-Dimethylpropyl)- benzene 119 17.243 0.45
29 1-Methyl-3-(1-methyl-2- propenyl)- benzene 119 17.632 0.30
30 2-Ethyl-1,3-dimethyl- benzene 119 17.797 0.31
31 1H-Indene, 2,3-dihydro-5-methyl- 117 18.12 1.67
32 2-Ethyl-1,3-dimethyl- benzene 119 18.301 0.96
33 1-Methyl-4-(1-methylethenyl) benzene 117 18.594 1.75
34 1H-Indene, 1-methyl- 132 18.928 0.24
35 2,3-dihydro-4,7-dimethyl-1H-Indene 131 19.272 2.41
36 1H-Indene, 2,3-dihydro-1,6-dimethyl- 131 19.726 1.22
37 Naphthalene 128 20.811 2.06
38 1H-Indene, 2,3-dihydro-4,7-dimethyl- 131 21.467 0.64
39 2-Ethenyl-1,3,5- trimethyl- benzene 131 21.946 0.57
40 Ethanone, 1-(4-ethylphenyl)- 133 22.191 0.40
41 Naphthalene, 1-methyl- 142 23.95 1.43
42 Naphthalene, 2-methyl- 142 24.628 0.60
aInternal standard
Table 8: Major VOCs identified in Babolroud river water samples.