Table 1.
The organic residue VOC composition obtained by HS-SPME and from the residue CH2Cl2 solution after direct GC and GC-MS analysis.
| No. | Compound | RI | A | B | C |
|---|---|---|---|---|---|
| 1. | Acetone | < 900 | 0.3 | 2.8 | - |
| 2. | Acetic acid | < 900 | 0.1 | 2.0 | - |
| 3. | Butan-2-one | < 900 | - | 0.6 | - |
| 4. | Ethyl acetate | < 900 | - | 0.4 | - |
| 5. | Benzene | < 900 | - | 0.2 | - |
| 6. | Propionic acid | < 900 | 0.1 | 2.1 | - |
| 7. | Heptane | < 900 | - | 0.7 | - |
| 8. | Ethyl propionate | < 900 | - | 0.4 | - |
| 9. | Isoamyl alcohol | < 900 | 0.3 | 0.9 | - |
| 10. | Toluene | < 900 | - | 0.5 | - |
| 11. | Butanoic acid | < 900 | - | 1.6 | - |
| 12. | Octane | < 900 | - | 1.6 | - |
| 13. | Furfural | < 900 | - | 0.5 | - |
| 14. | Isovaleric acid | < 900 | - | 0.4 | - |
| 15. | Ethylbenzene | < 900 | - | 0.4 | - |
| 16. | Isoamyl acetate | < 900 | 0.1 | 0.8 | - |
| 17. | p-Xylene | < 900 | - | 0.8 | - |
| 18. | Valeric acid | < 900 | - | 1.2 | - |
| 19. | Heptan-2-one | < 900 | - | 1.0 | - |
| 20. | Nonane | 900 | - | 0.6 | - |
| 21. | Heptanal | 905 | - | 0.4 | - |
| 22. | Isopropylbenzene (cumene) | 932 | - | 0.4 | - |
| 23. | α-Pinene | 941 | 0.1 | 0.2 | - |
| 24. | Camphene | 958 | 0.2 | 0.4 | - |
| 25. | Benzaldehyde | 965 | 0.6 | 20.4 | - |
| 26. | Hexanoic acid (caproic acid) | 994 | 0.1 | 4.6 | - |
| 27. | Octanal | 1007 | - | 0.7 | - |
| 28. | p-Cymene | 1032 | 0.1 | 2.7 | - |
| 29. | Limonene | 1036 | - | 0.5 | - |
| 30. | 2-Hydroxybenzaldehyde (salicylaldehyde) | 1052 | - | 0.2 | - |
| 31. | 1-Phenylethanone (acetophenone) | 1074 | - | 0.7 | - |
| 32. | Heptanoic acid | 1093 | - | 0.8 | - |
| 33. | Fenchone | 1094 | 0.2 | ||
| 34. | Nonan-2-one | 1097 | - | 1.3 | - |
| 35. | 1-Ethyl-4-(1-methylethyl)-benzene | 1110 | - | 1.6 | - |
| 36. | 2-Phenylethanol | 1116 | 1.2 | 3.3 | - |
| 37. | Camphor | 1153 | - | 0.9 | - |
| 38. | Pentylbenzene | 1165 | - | 0.4 | - |
| 39. | Borneol | 1175 | 1.1 | 4.5 | 0.2 |
| 40. | Naphthalene | 1190 | - | 1.2 | - |
| 41. | Octanoic acid | 1191 | 0.5 | 1.4 | - |
| 42. | 2-Methoxy-4-methylphenol (p-cresol) |
1198 | 0.3 | 0.9 | - |
| 43. | 3-Isopropylbenzaldehyde | 1229 | 0.4 | 4.7 | - |
| 44. | 4-Ethyl-2-methoxyphenol (4-ethylguaiacol) |
1286 | 0.4 | 0.9 | - |
| 45. | Nonanoic acid | 1288 | - | 0.5 | - |
| 46. | Bornyl acetate | 1291 | - | 0.6 | - |
| 47. | 1-Methylnaphthalene | 1316 | - | 0.4 | - |
| 48. | p-Acetylacetophenone | 1325 | - | 0.7 | - |
| 49. | 2-Methoxy-4-propylphenol | 1375 | 1.2 | 1.5 | - |
| 50. | 4-Hydroxy-3-methoxy-benzaldehyde (vanillin) | 1406 | 0.3 | - | - |
| 51. | 1,7-Dimethylnaphthalene ** | 1427 | 0.4 | 0.7 | - |
| 52. | 3,5-Dimethoxybenzaldehyde (syringaldehyde) | 1445 | 0.3 | 0.5 | - |
| 53. | 4-Hydroxy-3-methoxy-acetophenone (acetovanillone) | 1494 | 0.3 | - | - |
| 54. | α-Muurolene | 1507 | 0.6 | 0.9 | - |
| 55. | Calamenene | 1531 | 1.0 | 1.3 | - |
| 56. | γ-Cadinene | 1535 | 0.1 | - | - |
| 57. | α-Calacorene | 1551 | 0.1 | - | - |
| 58. | 2,3-Dimethylbenzofuran | 1578 | 0.3 | - | - |
| 59. | 1-Methyl-7-(1-methylethyl)-naphthalene (eudalin) | 1587 | 0.6 | 0.5 | - |
| 60. | 1,6,7-Trimethylnaphthalene * | 1590 | 0.3 | - | - |
| 61. | 1,6-Dimethyl-4-(1-methylethyl)-naphthalene (cadalin) | 1684 | 1.1 | 0.7 | - |
| 62. | 3,4-Diethyl-1,1′-biphenyl | 1751 | 0.4 | - | - |
| 63. | Anthracene | 1780 | 0.1 | - | - |
| 64. | 4-(1-Methyl-1-phenyl)-phenol (4-cumylphenol) | 1814 | 0.8 | - | - |
| 65. | Cembrene ** | 1912 | 2.0 | 0.7 | - |
| 66. | 2-Methylanthracene ** | 1925 | 1.8 | 0.5 | 0.3 |
| 67. | 1-Methoxy-8-methylnaphthalene * | 1942 | 2.2 | - | 0.3 |
| 68. | Hexadecanoic acid | 1963 | - | - | 0.9 |
| 69. | 7-(1-Methylethyl)-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydro-naphthalene | 1988 | 9.3 | 2.7 | 2.8 |
| 70. | 7-(1-Methylethyl)-1,4a-dimethyl-2,3,4,4a,9,10-hexahydro-phenanthrene | 1996 | 7.7 | 1.0 | 1.9 |
| 71. | 7-(1-Methylethyl)-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydro-phenanthrene | 2023 | 12.2 | 3.4 | 3.6 |
| 72. | 3,6-Dimethylphenanthrene ** | 2049 | 6.6 | 1.0 | 2.9 |
| 73. | 1,4-Dimethoxyphenathrene * | 2103 | 10.0 | 1.7 | 6.8 |
| 74. | 2,3,5-Trimethylphenanthrene | 2167 | 1.2 | - | 3.2 |
| 75. | 7-Ethenyl-1,2,3,4,4a,4b,5,6,7, 9,10,10a-dodecahydro-1,4a,7-trimethyl-1-phenanthrene-carboxaldehyde (pimaral) | 2187 | 0.6 | - | 0.8 |
| 76. | Methyl 8,15-pimaradien-18-oate | 2227 | 0.6 | - | 0.8 |
| 77. | 1-Methyl-7-(1-methylethyl)-phenanthrene (retene) | 2242 | 9.9 | 1.6 | 24.1 |
| 78. | Methyl 8,15-isopimaradien-18-oate | 2256 | 0.5 | - | 0.6 |
| 79. | 4-(2-Ethyl-5-phenyl-1H-pyrrol-3-yl)-pyridine * | 2382 | 0.7 | - | 4.2 |
| 80. | Methyl 6,8,11,13-abietatetraen-18-oate * | 2451 | - | - | 1.7 |
| 81. | Methyl dehydroabietate | 2477 | 6.0 | 1.0 | 33.6 |
| Total identified (%) | 85.1 | 94.7 | 88.7 | ||
RI = retention indices on HP-5MS column; A = solvent-free HS-SPME with the fiber PDMS/DVB; B = solvent-free HS-SPME with the fiber DVB/CARPDMS; C – the residue dissolved in CH2Cl2; - = not identified; * – tentatively identified; ** – correct isomer not identified.