Regiospecific analysis of Mono and Diglycerides in Glycerolysis products by GC x GC TOF-MS.

Comprehensive bidimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOF-MS) was used for the characterization of regiospecific mono- and diglycerides (MG-DG) content in the glycerolysis products derived from five different lipids included lard (LA), sun flower seed oil (SF), corn oil (CO), butter (BU), and palm oil (PA). The combination of fast and high temperature non-orthogonal column set namely DB17ht (6 m × 0.10 mm × 0.10 μm) as the primary column and SLB-5 ms (60 cm × 0.10 mm × 0.10 μm) as the secondary column was applied in this work. System configuration involved high oven ramp temperature to obtain precise mass spectral identification and highest effluent’s resolution. 3-Monopalmitoyl-sn-glycerol (MG 3-C16) was the highest concentration in LA, BU and PA while monostearoyl-sn-glycerol (MG C18) in CO and 1,3-dilinoleol-rac-glycerol (DG C18:2c) in SF. Principal component analysis accounted 82% of variance using combination of PC1 and PC2. The presence of monostearoyl-sn-glycerol (MG C18), 3-Monopalmitoyl-sn-glycerol (MG 3-C16), 1,3-dilinoleol-rac-glycerol (DG C18:2c), 1,3-dipalmitoyl-glycerol (DG 1,3-C16), and 1,3-dielaidin (DG C18:1t) caused differentiation of the samples tested

Effect of the Scots pine defoliation by herbivorous insects on chemical composition of needles, litter and soil

Effect of a weak defoliation by the larvae of the lappet moth and nun moth on chemical composition of needles, litter and soil in the 33−years old Scots pine stands was studied. The four variants were tested: I – larvae feeding, litterfall with frass and damaged needles, II – larvae feeding, but litterfall excluded (collected), III – no larvae, litterfall from the variant II spilled around trees, IV (untreated) – no larvae, litterfall without frass and damaged needles. No changes in chemical composition of litter and soil after two years of weak spring defoliation were found. However, there was a significant decrease of soluble carbohydrates and 5 sesquiterpenes as well as an increase of total monoterpenes in needles of trees in the variant II in comparison to other variants. All of those compounds are carbon−based, thus trees probably only relocated this element to a higher production of monoterpenes to make needles less attractive as a food source