Fig. 4

Gas chromatography-mass spectrometry analysis of extracts of Ph. papatasi eggs and first instars. Eggs (4.15 mg) were extracted with acetone containing 2 µg tridecanoic acid as internal standard (IS). Total ion chromatogram of egg extract (a) and extract of first-instars (c) are depicted. Mirrored downward chromatograms (b, d) show the respective acetone control. Dodecanoic acid (DA) and isovaleric acid (IVA) were identified. The retention times of the analyses in (c) and (d) are slightly different from those in (a) and (b) because they were run at different times. *Cyclosiloxane contaminants from plastic and plaster