New Method of Analysis of Lipids in Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) Insects by Direct Immersion Solid-Phase Microextraction (DI-SPME) Coupled with GC–MS
Abstract
:1. Introduction
2. Material and Methods
2.1. The Insect Culture
2.2. Chemical Reagents and Equipment Used
2.3. GC–MS Instrument and Analytical Conditions
2.4. The Extraction and Analytical Procedures
2.4.1. Preparation of Diluted Standards
2.4.2. Evaluation of the Effect of Different Solvents on DI-SPME for Extraction of Lipids from T. castaneum
2.4.3. Comparison of Lipid Compositions between Two Insect Species in Acetonitrile
2.5. Data Processing and Analysis
3. Results and Discussion
3.1. Effect of Direct Immersion on SPME Extraction in Solvent
3.2. Effect of Extraction Solvents
3.3. Comparison of Lipid Compositions between Two Insect Species
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Acknowledgments
Conflicts of Interest
References
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No. | Solvent | Compound Numbers | The Rate of Total Expected Compounds (%) | Number of Compounds Only Detected in Solvent |
---|---|---|---|---|
1 | Acetonitrile | 41 | 77.4 | 5 |
2 | Hexane | 23 | 43.4 | 1 |
3 | Ethanol | 25 | 47.2 | 0 |
4 | Methanol | 28 | 52.8 | 1 |
5 | Acetonitrile and ethanol (1:1 v/v) | 34 | 64.2 | 0 |
6 | Acetonitrile and water (1:1 v/v) | 22 | 41.5 | 0 |
7 | Ethanol and water (1:1 v/v) | 27 | 50.9 | 0 |
8 | Ethanol and acetonitrile and water (2:2:1 v/v/v) | 30 | 56.6 | 1 |
Chemical Standards | Formula | RT (min) | R2 | LOD (µg/g) | |
---|---|---|---|---|---|
1 | p-benzoquinone | C6H4O2 | 4.84 | 0.995 | 0.47 |
2 | p-benzoquinone, 2-methyl- | C7H6O2 | 6.72 | 0.976 | 0.36 |
3 | 1-pentadecene | C15H30 | 16.17 | 0.999 | 0.22 |
4 | Palmitic acid | C16H32O2 | 23.44 | 0.990 | 0.84 |
5 | Henicosane | C21H44 | 25.35 | 0.939 | 0.21 |
6 | Linolenic acid | C18H30O2 | 25.99 | 0.937 | 0.87 |
7 | Linoleic acid | C18H32O2 | 26.13 | 0.989 | 0.87 |
8 | Oleic acid | C18H34O2 | 26.43 | 0.993 | 0.89 |
9 | Docosane | C22H46 | 26.60 | 0.964 | 0.13 |
10 | Arachidic acid | C20H40O2 | 28.21 | 0.963 | 0.65 |
11 | Tricosane | C23H48 | 31.30 | 0.961 | 0.13 |
12 | Tetracosane | C24H50 | 32.24 | 0.920 | 0.21 |
13 | Pentacosane | C25H52 | 33.06 | 0.923 | 0.24 |
14 | Hexacosane | C26H54 | 34.41 | 0.961 | 0.14 |
15 | Heptacosane | C27H56 | 35.27 | 0.988 | 0.08 |
16 | Octacosane | C28H58 | 36.10 | 0.979 | 0.10 |
17 | Nonacosane | C29H60 | 37.40 | 0.987 | 0.08 |
18 | Triacontane | C30H62 | 39.52 | 0.988 | 0.08 |
19 | Hentriacontane | C31H64 | 41.48 | 0.982 | 0.09 |
20 | Cholesterol | C27H46O | 39.98 | 0.948 | 0.34 |
21 | Dotriacontane | C32H66 | 42.45 | 0.935 | 0.26 |
Compounds | RT (min) | NIST RI | Calculated RI | Qualitative m/z | GC Response (105) ± SD, n = 4 | Relative GC Response | Distribution Coefficient B/(A + B) × 100 | ||
---|---|---|---|---|---|---|---|---|---|
Cuticular Extraction (a) | Homogenized Body Extraction (b) | Cuticular | Homogenized Body | ||||||
2-methylbenzoquinone | 6.73 | 1116 | 1117 | 122 | 14 ± 1 | 29 ± 39 | 0.13 | 0.49 | 66.64 |
2-ethyl-p-benzoquinone | 8.66 | 1215 | 1212 | 108 | 47 ± 8 | 46 ± 4 | 0.41 | 0.78 | 49.27 |
1,4-benzenediol, 2-methyl- | 13.55 | 1223 | 1234 | 124 | 16 ± 3 | 65 ± 2 | 0.14 | 1.1 | 80.52 |
1,2-benzenediol, 4-ethyl- | 15.07 | 1392 | 1388 | 138 | 30 ± 3 | 105 ± 2 | 0.26 | 1.78 | 77.65 |
7-dodecenol | 15.83 | 1465 | 1468 | 165 | 72 ± 12 | 84 ± 4 | 0.63 | 1.43 | 53.86 |
1-pentadecene | 16.26 | 1502 | 1504 | 154 | 1250 ± 172 | 1336 ± 4 | 10.98 | 22.70 | 51.66 |
Benzene, 1-ethoxy-4-isothiocyanato- | 16.54 | 1527 | 1528 | 166 | 2 ± 0.3 | 2 ± 0.1 | 0.02 | 0.03 | 43.78 |
1-(2-hydroxy-4-methoxyphenyl)propan-1-one | 17.07 | 1538 * | 1558 | 151 | 47 ± 2 | 33 ± 3 | 0.40 | 0.56 | 41.42 |
7-hexadecene, (Z)- | 17.82 | 1620 | 1605 | 152 | 39 ± 1 | 28 ± 3 | 0.34 | 0.47 | 41.75 |
1,8,11-heptadecatriene, (Z,Z)- | 18.98 | 1655 | 1653 | 149 | ND | 11 ± 0.4 | ND | 0.19 | 100 |
cis-7-tetradecen-1-ol | 19.14 | 1660 | 1661 | 179 | 515 ± 60 | 357 ± 31 | 4.52 | 6.06 | 40.9 |
2-hexadecanol | 19.50 | 1702 | 1705 | 182 | 453 ± 36 | 374 ± 17 | 3.98 | 6.37 | 45.23 |
Myristic acid | 20.44 | 1752 | 1755 | 185 | ND | 0.82 ± 0.09 | ND | 0.01 | 100 |
Palmitoleic acid | 23.10 | 1936 | 1938 | 192 | 4 ± 0.3 | ND | 0.04 | ND | 0 |
Palmitic acid | 23.60 | 1954 | 1956 | 199 | 17 ± 2 | 143 ± 12 | 0.15 | 2.44 | 89.54 |
Linolenic acid | 26.15 | 2115 | 2119 | 222 | 3 ± 0.2 | 72 ± 5 | 0.03 | 1.23 | 96.01 |
Oleic acid | 26.25 | 2134 | 2125 | 220 | ND | 92 ± 4 | ND | 1.57 | 100 |
Stearic acid | 26.57 | 2153 | 2157 | 227 | 5 ± 0.6 | 45 ± 5 | 0.05 | 0.77 | 89.68 |
Unknown | 31.52 | - | 2505 | - | 12 ± 2 | 4 ± 0.4 | 0.10 | 0.08 | 26.71 |
Pentacosane | 33.30 | 2500 | 2515 | 238 | 33 ± 3 | 14 ± 0.7 | 0.29 | 0.24 | 30.49 |
Hexacosane | 33.85 | 2600 | 2612 | 266 | 174 ± 27 | 59 ± 3 | 1.53 | 1.00 | 25.3 |
Unknown | 34.06 | - | 2618 | - | 27 ± 2 | 38 ± 4 | 0.23 | 0.65 | 58.52 |
2-methylhexacosane | 34.28 | 2661 | 2684 | 294 | 105 ± 10 | 5 ± 0.7 | 0.92 | 0.08 | 4.418 |
13-methylheptacosane | 34.41 | 2731 | 2741 | 296 | 289 ± 22 | 274 ± 19 | 2.53 | 4.66 | 48.72 |
11-methylheptacosane | 34.82 | 2734 | 2750 | 309 | 2358 ± 186 | 969 ± 85 | 20.71 | 16.5 | 29.11 |
2-methylheptacosane | 35.02 | 2762 | 2766 | 336 | 635 ± 37 | 218 ± 14 | 5.57 | 3.71 | 25.57 |
3-methylheptacosane | 35.58 | 2773 | 2771 | 337 | 1409 ± 147 | 449 ± 17 | 12.37 | 7.64 | 24.17 |
Octacosane | 35.87 | 2800 | 2815 | 323 | 540 ± 35 | 118 ± 10 | 4.74 | 2.00 | 17.9 |
3-methyloctacosane | 36.28 | 2872 | 2849 | 351 | 531 ± 76 | 133 ± 10 | 4.66 | 2.27 | 20.05 |
Nonacosane | 36.60 | 2900 | 2902 | 365 | 177 ± 29 | 30 ± 3 | 1.55 | 0.51 | 14.58 |
Unknown | 36.85 | - | 2908 | - | 165 ± 18 | 41 ± 3 | 1.44 | 0.70 | 19.99 |
Unknown | 37.08 | - | 2911 | - | 437 ± 15 | 393 ± 31 | 3.83 | 6.68 | 47.36 |
Unknown | 37.49 | - | 2917 | - | 457 ± 40 | 23 ± 2 | 4.01 | 0.40 | 4.86 |
13-methylnonacosane | 37.58 | 2930 | 2927 | 379 | 766 ± 74 | 71 ± 7 | 6.73 | 1.21 | 8.52 |
11-methylnonacosane | 37.92 | 2939 | 2950 | 393 | 31 ± 2 | ND | 0.27 | ND | 0 |
Nonacosane, 2-methyl- | 38.13 | 2962 | 2961 | 421 | 229 ± 16 | 79 ± 2 | 2.42 | 1.34 | 25.56 |
3-methylnonacosane | 38.44 | 2974 | 2973 | 395 | 275 ± 17 | 10 ± 1 | 2.41 | 0.16 | 3.351 |
Triacontane | 39.64 | 3000 | 3003 | 239 | 141 ± 17 | 13 ± 1 | 1.24 | 0.22 | 8.425 |
Cholesterol | 40.20 | 3087 | 3060 | 386 | 29 ± 1 | 75 ± 6 | 025 | 1.29 | 73.01 |
Desmosterol | 40.51 | 3125 | 3133 | 364 | 15 ± 2 | 29 ± 1 | 0.13 | 0.49 | 66.06 |
Dotriacontane | 42.37 | 3200 | 3203 | 449 | 36 ± 1 | 13 ± 1 | 0.32 | 0.22 | 26.27 |
Compounds | RT (min) | NIST RI | Calculated RI | Qualitative M/Z | GC Response (105) ± SD, n = 4 | Relative GC Response | Distribution Coefficient B/(A + B) × 100 | ||
---|---|---|---|---|---|---|---|---|---|
Cuticular Extraction (A) | Homogenized Body Extraction (B) | Cuticular | Homogenized Body | ||||||
Palmitic acid | 23.53 | 1954 | 1956 | 199 | 21 ± 3 | ND | 0.53 | ND | 0 |
Linolenic acid | 26.06 | 2115 | 2119 | 222 | 6 ± 0.7 | 51 ± 5 | 0.17 | 4.39 | 88.72 |
Stearic acid | 26.42 | 2153 | 2157 | 227 | 3 ± 0.3 | 13 ± 3 | 0.07 | 1.15 | 83.79 |
Octadecanamide, N-(2-hydroxyethyl)- | 29.16 | 2347 | 2347 | 280 | 17 ± 0.7 | 9 ± 1 | 0.43 | 0.75 | 34.31 |
Unknown | 31.46 | - | 2515 | - | 17 ± 3 | ND | 0.45 | ND | 0 |
11-methylpentacosane | 31.94 | 2535 | 2555 | 281 | 5 ± 0.8 | 3 ± 0.2 | 0.12 | 0.28 | 41.64 |
Unknown | 32.91 | - | 2628 | - | 17 ± 2 | ND | 0.45 | ND | 0 |
13-methylheptacosane | 34.41 | 2731 | 2741 | 296 | 291 ± 56 | 209 ± 26 | 7.52 | 18.10 | 41.77 |
2-methylheptacosane | 34.98 | 2762 | 2766 | 336 | 166 ± 13 | 31 ± 6 | 4.28 | 2.66 | 15.64 |
3-methylheptacosane | 35.34 | 2773 | 2771 | 337 | 154 ± 28 | 7 ± 1 | 3.98 | 0.59 | 4.20 |
Octacosane | 35.82 | 2800 | 2815 | 323 | 45 ± 4 | 33 ± 7 | 1.16 | 2.89 | 42.77 |
Unknown | 37.10 | - | 2912 | - | 321 ± 25 | 15 ± 2 | 8.30 | 1.32 | 4.54 |
13-methylnonacosane | 37.58 | 2930 | 2927 | 379 | 33 ± 3 | 234 ± 21 | 0.84 | 20.3 | 87.79 |
Triacontane | 39.64 | 3000 | 3003 | 239 | 156 ± 30 | 16 ± 2 | 4.04 | 1.44 | 9.59 |
Cholesterol | 40.00 | 3087 | 3060 | 386 | 12 ± 1 | 48 ± 8 | 0.32 | 4.21 | 79.67 |
Hentriacontane | 41.22 | 3100 | 3117 | 435 | 65 ± 3 | 23 ± 3 | 1.69 | 1.98 | 25.93 |
2-methylhentriacontane | 41.53 | 3162 | 3152 | 436 | 68 ± 5 | 28 ± 5 | 1.77 | 2.46 | 29.39 |
3-methylhentriacontane | 42.01 | 3172 | 3182 | 424 | 29 ± 6 | 14 ± 3 | 0.75 | 1.21 | 32.50 |
Dotriacontane | 42.37 | 3200 | 3203 | 449 | 271 ± 51 | 6 ± 0.9 | 7.00 | 0.52 | 2.16 |
10-methyldotriacontane | 42.50 | 3235 | 3218 | 477 | 540 ± 57 | 64 ± 7 | 14.00 | 5.55 | 10.61 |
8-methyldotriacontane | 42.60 | 3240 | 3221 | 450 | 92 ± 6 | 118 ± 9 | 2.37 | 10.20 | 56.17 |
Unknown | 42.78 | - | 3231 | - | 181 ± 12 | 17 ± 2 | 4.69 | 1.46 | 8.53 |
Unknown | 42.87 | - | 3237 | - | 66 ± 12 | ND | 1.70 | ND | 0 |
Unknown | 42.96 | - | 3249 | - | 243 ± 36 | 24 ± 4 | 6.29 | 2.08 | 8.98 |
Dotriacontane, 2-methyl- | 43.22 | 3263 | 3266 | 481 | 260 ± 38 | 30 ± 5 | 6.29 | 2.64 | 10.47 |
Unknown | 43.40 | - | 3276 | - | 240 ± 20 | 42 ± 5 | 6.22 | 3.66 | 14.95 |
15-methyltritriacontane | 44.03 | 3333 | 3323 | 463 | 384 ± 60 | 29 ± 5 | 9.93 | 2.55 | 7.11 |
Unknown | 44.47 | - | 3351 | - | 58 ± 6 | 63 ± 12 | 1.50 | 5.47 | 52.17 |
Tetratriacontane | 44.88 | 3400 | 3387 | 492 | 65 ± 12 | 11 ± 0.7 | 1.68 | 0.95 | 14.40 |
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Alnajim, I.; Du, X.; Lee, B.; Agarwal, M.; Liu, T.; Ren, Y. New Method of Analysis of Lipids in Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) Insects by Direct Immersion Solid-Phase Microextraction (DI-SPME) Coupled with GC–MS. Insects 2019, 10, 363. https://doi.org/10.3390/insects10100363
Alnajim I, Du X, Lee B, Agarwal M, Liu T, Ren Y. New Method of Analysis of Lipids in Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) Insects by Direct Immersion Solid-Phase Microextraction (DI-SPME) Coupled with GC–MS. Insects. 2019; 10(10):363. https://doi.org/10.3390/insects10100363
Chicago/Turabian StyleAlnajim, Ihab, Xin Du, Byungho Lee, Manjree Agarwal, Tao Liu, and Yonglin Ren. 2019. "New Method of Analysis of Lipids in Tribolium castaneum (Herbst) and Rhyzopertha dominica (Fabricius) Insects by Direct Immersion Solid-Phase Microextraction (DI-SPME) Coupled with GC–MS" Insects 10, no. 10: 363. https://doi.org/10.3390/insects10100363