Changes in PAH and 3-MCPDE contents at the various stages of Camellia oleifera seed oil refining

Objectives:Polycyclic aromatic hydrocarbons(PAHs)and 3-monochloropropane-1,2-diol ester(3-MCPDE)were studied in camellia oil.It is important to study the changes in the content of PAHs and 3-MCPDE at different refining stages(from crude oil to the final refined oil product)to elucidate the influence of the refining procedures on their change.Materials and methods:The PAHs and 3-MCPDE in camellia oil from different refining stages(from crude oil to the product)of a plant were analyzed by gas chromatography–mass spectrometry and calculated by the internal standard method.Results:The overall PAH content was(79.64±2.43)μg/kg in crude camellia oil.After refining treatment,the PAH content decreased to(18.75±0.55)μg/kg.The 3-MCPDE content increased during the refining process from 0 mg/kg in the crude oil to 4.62 mg/kg in the refined oil product.Conclusions:This is the first study to simultaneously monitor changes in both PAH and 3-MCPDE contents during the production of camellia oil.These results confirmed the effectiveness of the refining method on PAH removal and the increase in 3-MCPDE at high temperature.It is suggested that novel processing methods or refining parameters need further optimization to decrease the overall concentrations of PAHs and 3-MCPDE in camellia oil.

Hydrogen bonding-induced oxygen clusters and long-lived room temperature phosphorescence from amorphous polyols

Developing non-conjugated luminescent polymers(NCLPs)with fluorescence and long-lived roomtemperature phosphorescence is of great significance for revealing the essence of NCLPs luminescence,which has gradually attracted the attention of researchers in recent years.Herein,polymethylol(PMO)and poly(3-butene-1,2-diol)(PBD)with polyhydroxy structures were prepared and their luminescence behaviors were investigated to reveal the clusteroluminescence(CL)mechanism.Compared with polyvinyl alcohol with non-luminescent behavior,PMO and PBD exhibit cyan-blue fluorescence with quantum yields of ca.12%and green room-temperature phosphorescence with lifetimes of ca.89 ms in the solid state.Both fluorescence and phosphorescence exhibit typical excitation-dependent CL behavior.Experimental and theoretical analyses show that the strong hydrogen-bonding interaction of PMO and PBD greatly promotes the formation of oxygen clusters and the through-space n-n interaction of oxygen atoms,enabling fluorescence and phosphorescence emission.Our results have enormous implications for understanding the CL mechanism of NCLPs and provide a new polymer design strategy for the rational design of novel NCLPs materials.