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Solid-phase microextraction (SPME) analysis of six Italian populations of Ephedra nebrodensis Tineo ex Guss. subsp. nebrodensis.

Chemistry & biodiversity (2011-01-25)
Filippo Maggi, Marcello Nicoletti, Valentina Petitto, Gianni Sagratini, Fabrizio Papa, Sauro Vittori
RÉSUMÉ

Headspace solid-phase microextraction (HS-SPME) coupled with GC/FID and GC/MS was applied for the first time in the analysis of the volatile fraction of an Ephedra species. Notably, six Italian populations (Marche, Abruzzo, and Sardinia) of Ephedra nebrodensis subsp. nebrodensis, covering almost the entire Italian area, were investigated to examine the chemical variability and to support the taxonomy of the species. A fiber screening with polymethylsiloxane (PDMS), Carboxen(TM) /polymethylsiloxane (CAR/PDMS), and polymethylsiloxane/divinylbenzene (PDMS/DVB) coatings, together with an optimization of the extraction conditions were carried out before analysis of the six populations. A total of 119 volatiles were identified in the headspace of different samples, accounting for 63.35-100.00% of the total volatiles. A great variability was found in the qualitative composition of different samples, since only 18 components were in common among all populations. The headspace composition was dominated by sesquiterpene hydrocarbons (52.30-88.32%), with β-maaliene (traces-7.49%), β-patchoulene (traces-1.29%), β-panasinsene (traces-6.85%), α-isocomene (traces-31.25%), α-trans-bergamotene (traces-6.95%), alloaromadendrene (traces-33.20%), α-acoradiene (traces-9.41%), and γ-muurolene (0.61-16.33%) being the most abundant constituents. Noteworthy is the occurrence in a sample of two major unknown sesquiterpenes, one hydrocarbon (24.49%, RI: 1396) and one oxygenated compound (10.37%, RI: 1591), whose mass spectra were reported for the first time. Multivariate chemometric techniques, such as cluster analysis (CA) and principal component analysis (PCA), were used to characterize the samples according to the geographical origin.

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Description du produit

Supelco
Fibres SPME Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, StableFlex
Supelco
Fibres SPME Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 23 ga, StableFlex, for use with autosampler
Supelco
Fibres SPME Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, for use with manual holder
Supelco
Fibres SPME Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 23 ga, StableFlex, for use with manual holder or autosampler, fiber L 2 cm
Supelco
Fibres SPME Divinylbenzene/Carboxen/Polydimethylsiloxane (DVB/CAR/PDMS), needle size 24 ga, StableFlex, for use with autosampler
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Tube ORBO Carboxen-564, W,F,F separators, O.D. × L 6 mm × 75 mm, pkg of 25 ea, for analyte group MEK (methylethyl ketone)
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Adsorbant Carboxen®, matrix Carboxen® 1000, 60-80 mesh, bottle of 10 g
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ORBO-78 400/200 MG PK/25, W,W,W separators, O.D. × L 6 mm × 110 mm, pkg of 25 ea
Supelco
PLOT - Carboxen-1010, L × I.D. 30 m × 0.53 mm, average thickness 30 μm
Supelco
Unité de fibres SPME, carboxène/polydiméthylsiloxane (CAR/PDMS), df 75 μm(CAR/PDMS, for use with manual holder, needle size 24 ga
Supelco
Unité de fibres SPME, carboxène/polydiméthylsiloxane (CAR/PDMS), df 85 μm(CAR/PDMS, needle size 23 ga, StableFlex, for use with autosampler
Supelco
PLOT - Carboxen-1006, L × I.D. 30 m × 0.53 mm, average thickness 30 μm
Supelco
Unité de fibres SPME, carboxène/polydiméthylsiloxane (CAR/PDMS), df 75 μm(CAR/PDMS, needle size 24 ga, for use with autosampler
Supelco
Unité de fibres SPME, carboxène/polydiméthylsiloxane (CAR/PDMS), df 85 μm(CAR/PDMS, needle size 24 ga, for use with manual holder, StableFlex fiber
Supelco
Unité de fibres SPME, carboxène/polydiméthylsiloxane (CAR/PDMS), df 85 μm(CAR/PDMS, needle size 24 ga, StableFlex, for use with autosampler
Supelco
PLOT - Carboxen-1010, L × I.D. 30 m × 0.32 mm, average thickness 15 μm
Supelco
Unité de fibres SPME, carboxène/polydiméthylsiloxane (CAR/PDMS), df 75 μm(CAR/PDMS, needle size 23 ga, for use with autosampler
Supelco
Unité de fibres SPME, carboxène/polydiméthylsiloxane (CAR/PDMS), df 75 μm(CAR/PDMS, needle size 23 ga, for use with manual holder
Supelco
Adsorbant Carboxen®, matrix Carboxen® 572, 20-45 mesh, bottle of 10 g