ELECTRONIC SUPPLEMENTARY MATERIAL

SOLID PHASE MICRO-EXTRACTION (SPME) WITH IN SITU TRANSESTERIFICATION: AN EASY METHOD FOR THE DETECTION OF NON-VOLATILE FATTY ACID DERIVATIVES ON THE INSECT CUTICLE

Stephan Kühbandner*, Joachim Ruther

Institute of Zoology, University of Regensburg, Universitätsstraße 31, D-93053, Regensburg, Germany,

*Author for correspondence:


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Fig. S6

Fig. S1-S6 Total ion chromatograms of fatty acid methyl esters (FAME) from non-volatile fatty acid derivatives (NFADs, upper traces) originating from different insect species. NFADs were sampled by SPME with in situ transesterification using trimethyl sulfonium hydroxide (TMSH). In SPME control 1, the SPME fiber was soaked in TMSH without being rubbed over the insect cuticle to control for the absence of NFAD contamination of the GC/MS. In SPME control 2, the fiber was rubbed over the insects without being soaked into TMSH to exclude the occurrence of free fatty acids on the insect cuticle, which would likewise furnish FAMEs. The following fatty acids were detected: C14 = tetradecanoic acid, C14:1 = (Z)-tetradec-9-enoic acid, C15 = pentadecanoic acid, C16 = hexadecanoic acid, C16:1 = (Z)-hexadec-9-enoic acid, C17 = heptadecanoic acid, C18 = octadecanoic acid, C18:1 = (Z)-octadec-9-enoic acid, C18:2 = (9Z,12Z)-octadeca-9,12-dienoic acid, OCC = other cuticular compounds. Chromatograms within one figure (SPME, SPME control 1 and SPME control 2) are scaled at the same intensity level.

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ELECTRONIC SUPPLEMENTARY MATERIAL

Table S1 Mean amounts of fatty acids from cuticular lipids (ng per individuum ±SE, N=3) analyzed by GC/MS and sampled by solvent extraction/transesterification.

Formula / Mass / Lariophagus distinguendus / Nasonia vitripennis / Drosophila melanogaster / Asobara tabida / Nicrophorus vespilloides / Periplaneta americana
dodecanoic acid / C12:0 / 200 / - / - / 1±1 / - / - / 1±0
unknown fatty acid 1 / - / - / - / - / 1±1 / - / - / 1±1
(Z)-tetradec-9-enoic acid / C14:1 / 226 / - / - / 2±1 / - / - / -
unknown fatty acid 2 / - / - / - / - / 1±0 / - / - / -
tetradecanoic acid / C14:0 / 228 / 1±0 / - / 22±11 / 1±1 / 56±34 / 14±4
unknown fatty acid 3 / - / - / - / - / - / - / - / 1±1
pentadecanoic acid / C15:0 / 242 / - / - / - / - / - / 2±1
C16:1 / C16:1 / 254 / 1±0 / 0±0 / 1±1 / - / 51±30 / 8±4
(Z)-hexadec-9-enoic acid / C16:1 / 254 / 3±0 / 3±2 / 51±28 / 2±1 / 140±80 / 24±11
hexadecanoic acid / C16:0 / 256 / 32±5 / 7±3 / 67±34 / 7±3 / 1400±1100 / 440±150
unknown fatty acid 4 / - / - / - / - / - / - / - / 1±1
unknown fatty acid 5 / - / - / - / - / - / - / - / 1±1
unknown fatty acid 6 / - / - / - / - / - / - / - / 2±2
(Z)-heptadec-10-enoic acid / C17:1 / 268 / - / - / - / - / 88±40 / -
(6Z,9Z,12Z)-octadeca-6,9,12-trienoic acid / C18:3 / 278 / - / - / - / - / - / 1±1
(9Z,12Z)-octadeca-9,12-dienoic acid / C18:2 / 280 / 23±5 / 6±3 / 23±12 / 1±1 / 2200±1700 / 650±200
(Z)-octadec-9-enoic acid / C18:1 / 282 / 60±11 / 13±5 / 120±58 / 7±2 / 6300±4700 / 1200±430
(E)-octadec-9-enoic acid / C18:1 / 282 / - / 2±1 / - / 8±7 / 29±4
octadecanoic acid / C18:0 / 284 / 15±3 / 2±1 / 6±2 / 4±2 / 290±210 / 190±40
nonadecanoic acid / C19:0 / 298 / - / - / - / - / 3±2 / 9±1
unknown fatty acid 7 / - / - / - / - / - / - / - / 11±5
unknown fatty acid 8 / - / - / - / - / - / - / - / 4±2
(11Z,14Z,17Z)-eicosa-11,14,17-trienoic acid / C20:3 / - / - / - / - / - / - / 2±2
unknown fatty acid 9 / - / - / - / - / - / - / - / 2±2
(11Z,14Z)-eicosa-11,14-dienoic acid / C20:2 / 308 / - / - / - / - / - / 13±3
(Z)-eicos-11-enoic acid / C20:1 / 310 / - / - / - / - / - / 22±4
eicosanoic acid / C20:0 / 312 / 1±0 / - / 0±0 / - / 100±7 / 5±2
docosanoic acid / C22:0 / 340 / - / - / - / 1±0 / 60±9 / -
tetracosanoic acid / C24:0 / 368 / - / - / - / - / - / 2±1
total amount / - / - / 140 / 33 / 300 / 23 / 10700 / 2600

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