Separation of methyl linolenate and its analogues by functional mixture of imidazolium based ionic liquid-organic solvent-cuprous salt

Methyl linolenate was separated from its analogues by a new extraction system constructed by solvent,imidazolium based ionic liquids and cuprous salt. Firstly, the effect of ionic liquid on the dissolution of CuCl in acetonitrile, N,N-dimethylformamide(DMF), methanol and water was evaluated by visual observation.[C4Mim][Cl]can improve the dissolution of CuCl in acetonitrile. Then, for the new system as acetonitrile-ILs-CuCl, extraction equilibrium, distribution ratio and selectivity of methyl linolenate and its analogues were determined by gas chromatography analysis and the mass balance. The extraction time, IL structures and CuCl concentrations were investigated. Distribution ratio decreased slightly, but selectivity increased significantly with the addition of CuCl,[C4Mim][Cl] or [C4Vim][NTF2] into acetonitrile.[C4Vim][NTF2] had higher selectivity than [C4Mim][Cl].But the selectivity of the system combining CuCl with [C4Vim][NTF2] was much lower than with [C4 Mim][Cl].For the CuCl-[C4Mim][Cl]-acetonitrile, the extraction efficiency was better than CuCl-acetonitrile, increasing Cu^+ concentration effectively improved the separation selectivity when ratio of CuCl/[C4Mim][Cl] was less than 1. Compared with previous aqueous AgNO3 extractions, the method of using CuCl is a much cheaper and practical way to enrich unsaturated fatty acid.

Application of silver-based dihydric alcohol to the extraction of methyl linolenate with high extractability and stability replacing ionic liquids

A novel silver-based dihydric alcohol extractant was substituted for ionic liquids to enrich methyl linolenate(C18-3)from tallow seed oil methyl ester in this study.The interactions among dihydric alcohol,Ag(I)and C18-3 were explored by FT-IR spectroscopy.The effects of dihydric alcohol structure,carrier Ag(I)concentration,temperature and initial feed concentration on extraction yield and selectivity were reported.The good extraction performance was achieved by 1,4-butanediol containing AgBF4.The complexation of Ag(I)with C18-3 was dominant in extraction operation rather than physical partition.Furthermore,a multi-step reverse extraction method was proposed to obtain C18-3 product and regenerate the extractant.1-Hexene as the stripping phase can facilitate C18-3 reverse extraction.The content of C18-3 in the product was up to 93.36%,and the yield was 73.76%.This work opened a new route for the utilization of the dihydric alcohol properties to manipulate the carrier efficiency for extracting unsaturated fatty acid methyl esters at a lower cost.

Prototethyan orogenesis in southwest Yunnan and Southeast Asia

The Prototethyan Ocean has been suggested as an Early Paleozoic Ocean developed at the Gondwana northern margin. However, its spatial pattern, subduction style and closure time in SW Yunnan and SE Asia still remain unknown. The Prototethyan evolution in SW Yunnan and SE Asia and its internal connection with the South China Kwangsian(Ordo-Silurian)intracontinental orogenesis are also poorly constrained. By summarizing and analyzing the Early Paleozoic geological records in the Sibumasu and Indochina blocks, the eastern South China and SW Japan, this paper proposes the existence of a giant OrdoSilurian igneous belt along the Gondwana northern margin. A preliminary limitation has been obtained regarding the source nature and migration pattern of the igneous belt. Our data allow us to propose a model of the Early Paleozoic Andean-type active continental margin along the East Gondwana northern margin. This is the foundation to determine the southward subduction of the southern branch of the eastern Prototethyan Ocean underneath the Sibumasu and Indochina blocks along the YunxianMenghai(SW Yunnan)-Thailand Peninsula and the Tam Ky-Phouc Son suture in Central Vietnam, respectively, and the eastward linkage with the Early Paleozoic Osaka subduction zone in SW Japan across the peripheral Sanya area. These data synthetically indicate an easterly-diachronous and propagating Andean-type Cambrian(Furongian)-Silurian(Llandovery) orogenesis along the Gondwana northern margin from Nepal, NW India, South Tibet, Qiangtang to Central Vietnam across South Indochina and Sibumasu. This paper reconstructs the Early Paleozoic locations of the Sibumasu and Indochina fragments, as well as SW Japan and South China continent in the Gondwana northern margin, and proposes the far-field effect on the South China Kwangsian intra-continental orogenesis from the subduction of the Early Paleozoic Prototethyan southern branch.