Improvement of saponification extraction method for fatty acids separation from geological samples

The conventional saponification method could result in lower recoveries and artificial changes of longchain fatty acids. The main reason is the error judgment of the intermediate layer suspended between the aqueous and organic layer during the liquid–liquid extraction process.This study shows that the intermediate layer consists of lots of medium- to long-chain carboxylic salts for their special physical and chemical properties. An improved saponification extraction method is also developed and the results show that the carboxylic salts distributed in the intermediate layer could be obtained completely, which greatly enhances the authenticity and accuracy of fatty acid analysis. Additionally, the possible reasons of formation of the intermediate layer are also discussed.

Paleozoic Multi-Stage Magmatic Events Related to Proto-Tethys and Paleo-Tethys Evolution:Insights from Intrusive Rocks in the Eastern Altyn Orogen,NW China

Abundant mafic-felsic intrusions distributed in the Altyn Orogen record orogenic histories related to Proto-Tethys and Paleo-Tethys evolution.Zircon U-Pb dating of the intrusive rocks in the eastern Altyn Orogen identifies at least three major tectono-magmatic episodes,yielding ages of∼426,∼376–373 and∼269–254 Ma.The first two emplacement episodes correspond to the post-collisional magmatism in the Altyn Orogen.The∼426 Ma granitoids possess adakitic characteristics coupled with enriched isotopes,suggesting that they originated from partial melting of thickened lower continental crust induced by upwelling asthenospheric mantle after slab break-off of the South Altyn Ocean Plate.Next,the∼376–373 Ma mafic-intermediate rocks and coeval granitoids represent a large thermal event that involved mantle melting with induced new juvenile lower continental crust melting in a post-collisional extensional setting.Finally,the∼254 Ma diabase dykes intruded into the∼269 Ma granitoids,which were related to the widespread Late Paleozoic magmatism resulting from Paleo-Tethys Ocean subduction.Post-collisional magmatism in the Altyn Orogen significantly enhances understanding of the tectono-magmatic evolution in the northern Tibetan Plateau.The penetrative influence of Paleo-Tethys Ocean subduction was more extensive than previously thought.

Thermal-induced polycondensation of soluble organic matter in coal of lower maturation stage

A brief discussion is given to the thermal-induced polycondensation of soluble organic matter (SOM) in coal during lower maturation stage, based on laboratory simulation on hydrocarbon generation from coal and on correlation with natural maturation of coal. An essential relationship between the retrogressive variation of SOM and thermal-induced polycondensation during the lower maturation stage has been established.

The simulation of the formation of dibenzothiopheneand dibenzofuron

The results of simulation indicate that biphenyl (BIP) is one of the original materials of dibenzothiophene (SF) and dibenzofuron (OF). It has the fundamental structure of SF and OF. As the radicals that attract electron, its two aromatic nucleuses influence each other, which make the α-H active. The strong electronegative sulphur or oxygen atoms attack the two places of the two aromatic nucleuses, seize the hydrogens and form H 2S or H 2O, the other sulphur or oxygen atoms attacking the two places which have lost hydrogens can put up a bridge and make the BIP molecule which can freely turn become a stable SF or OF molecule. So SF and OF have no definite relation with fluorene (F).