## 3 Results
### FTIR-ATR Spectral Profiling  
A characteristic FTIR-ATR spectrum of bee pollen (obtained as an average spectrum of the entire set of multifloral and unifloral bee pollen spectra) with assignation of major underlying molecular vibrations is presented in Figure 1.  
A typical FTIR-ATR spectrum of bee pollen is characterized by the broad absorption observed in the spectral range from 3600 to 3000 cm\({}^{-1}\) with an absorption maximum at 3285 cm\({}^{-1}\), which can be assigned to both N-H stretching vibrations of the protein structure (amide A band) [39; 40], and O-H stretching vibrations of carbohydrates (primarily glucose, fructose, and sucrose) and water. Two IR absorptions, the medium intensity absorption band observed at 2925 cm\({}^{-1}\) and the weaker one at 2854 cm\({}^{-1}\), correspond to C-H stretching (aliphatic C-H groups) and can be described as non-specific IR signals given that they may be related to the molecular vibrations of numerous bee pollen constituents, such as lipids, fatty acids, carbohydrates, cellulose, and other long-chain structures [11; 24; 25; 26; 27]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**No.** & **Compound** & & & & & & **Sample*** & \\ \cline{5-8}  & & RI* & A & B & C & D & E & F \\ \cline{2-8}
21. & Sabinene & 982 & - & - & - & - & 1.21 & - \\
22. & \(\beta\)-Pinene & 985 & 2.16 & 2.37 & 0.86 & 1.57 & - & - \\
23. & Hexanoic acid & 986 & - & - & - & - & - & - \\
24. & 6-Methylhept-5-en-2-one & 989 & 5.81 & 8.33 & 1.91 & 9.56 & 2.50 & 1.53 \\
25. & \(\beta\)-Myrence & 993 & - & - & - & - & - & - \\
26. & Octanal & 1005 & - & 0.89 & 0.33 & - & - & 0.57 \\
27. & (_E,E_)-Hepta-2,4-dienal & 1015 & - & - & 0.65 & - & - & \\
28. & 2-Ethylewan-1-ol & 1035 & - & - & - & 1.23 & 5.41 & 0.87 \\
29. & 1.8-Cineole & 1039 & - & 0.99 & - & 2.45 & - & - \\
30. & Benzyl alcohol & 1046 & - & 1.04 & - & 3.26 & - & - \\
31. & Phenylacetaldehyde & 1050 & 5.46 & 5.69 & 3.67 & 11.79 & 1.57 & 0.44 \\
32. & (_E_)-\(\beta\)-Ocymene & 1053 & 4.06 & 5.27 & - & - & - & - \\
33. & (_E,E_)-Ota-3,5-diene-2-one & 1075 & 0.42 & 2.40 & 5.03 & 1.77 & 1.82 & 0.33 \\
34. & (_E,Z_)-Ota-3,5-diene-2-one & 1096 & 0.30 & 0.29 & - & - & - & - \\
35. & Undecane & 1100 & - & - & - & - & 0.98 & 0.54 \\
36. & Linalool & 1103 & 1.79 & 1.94 & 0.45 & 0.87 & - & - \\
37. & Nonanal & 1105 & 28.67 & 15.53 & 4.60 & 8.14 & 3.65 & 5.19 \\
38. & \(\beta\)-PInjome & 1109 & - & - & - & 1.21 & - & - \\
39. & 2-Phenylethanol & 1122 & - & 2.60 & - & 0.91 & - & - \\
40. & Methyl octanoate & 1128 & - & 0.99 & - & 0.64 & 4.35 & - \\
41. & Lilac aldehyde A & 1146 & - & - & 3.12 & - & 5.61 & 14.69 \\
42. & Lilac aldehyde B & 1155 & - & - & 5.20 & - & 9.00 & 25.04 \\
43. & Lilac aldehyde D & 1169 & - & - & 2.16 & - & 3.28 & 14.51 \\
44. & Ethyl octanoate & 1198 & - & - & - & - & 1.68 & - \\
45. & Dodecane & 1200 & - & 0.51 & 0.39 & 0.40 & 0.62 & - \\
46. & Lilac alcohol A & 1205 & - & - & - & - & - & 2.99 \\
47. & Decanal & 1207 & 1.35 & 0.77 & - & - & - & - \\
48. & Verbenone & 1211 & - & - & - & - & 1.09 & - \\
49. & Lilac alcohol B & 1214 & - & - & 0.24 & - & - & 5.32 \\
50. & \(\beta\)-Cyclocitral & 1223 & - & - & - & - & - & 3.28 \\
51. & Lilac alcohol D & 1232 & - & - & - & - & - & 1.10 \\
52 & Nerol & 1234 & - & - & 1.22 & - & - & - \\
53. & 4-Methoxybenzaldehyde & 1264 & - & - & - & - & 5.66 \\
54. & Methyl decanoate & 1327 & - & 0.49 & - & - & 0.81 & - \\
55. & Tetradecane & 1400 & - & - & - & 0.96 & - & 0.27 \\
56. & \(\alpha\)-Ionone & 1429 & - & - & - & - & - & 0.92 \\
57. & (E)-Geranyl acetone & 1455 & 2.44 & 3.51 & - & 4.07 & - & - \\
58. & (E)-\(\beta\)-Ionone & 1512 & - & - & - & - & - & 2.24 \\
59. & \(\beta\)-Tumerone & 1668 & - & - & - & 0.69 & - & - \\
60. & Heneicosane & 2100 & - & 1.74 & - & 0.90 & 6.17 & 0.66 \\ \hline \end{tabular}  
* A, _pubescens_; B, _Malus_ spp.; C, _S. vulgaris_; D, _R. lutar_; E, _C. biemnis_; F, _P. malable_; RI, retention indices on HP-5 MS column.  
\end{table}