Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids we...Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).展开更多
Carbon quantum dots（CQDs） have emerged as a new generation of photoluminescent nanomaterials with wide applications.Among the various synthetic routes for CQDs,the acid-refluxing method,which belongs to the group of...Carbon quantum dots（CQDs） have emerged as a new generation of photoluminescent nanomaterials with wide applications.Among the various synthetic routes for CQDs,the acid-refluxing method,which belongs to the group of ＂top-down＂ methods,offers the advantage of large-scale production of CQDs and uses cheap and abundantly available starting materials.In this study,we evaluated the potential of fullerene carbon soot（FCS）,a by-product obtained during the synthesis of fullerene,as the starting material for CQD production.It was found that FCS can be successfully converted to CQDs in high production yield in mixed acids,i.e.,concentrated HNO_3 and H_2SO_4,under mild conditions.The fluorescence quantum yield（0） of the as-produced CQDs is in the range of 3%-5%,which is the highest value for CQDs obtained from ＂top-down＂ methods.Importantly,the CQDs prepared by this method show emission in the yellow range of the visible light,which is advantageous for their various potential applications.Further investigations reveal that the CQDs are highly photostable over a wide pH range and show good resistance against ionic strength and long-term UV irradiation.This further expands their potential use under harsh conditions.展开更多
基金National Natural Science Foundation of China(51832007,51872286)National Key Research and Development Program of China(2022YFB3605704)+4 种基金NSFC-Joint Funds for Regional Innovation and Development(U21A20508)Science and Technology Plan Leading Project of Fujian Province(2022H0043,2020H0036)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(2021ZR204,2020zz108)The 14th Five-year Plan Project of FJIRSM(E255KL0101)Science and Technology Service Network Initiative(2019T3006)。
文摘Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).
基金supported by the National Natural Science Foundation of China(21402215 and 61474124)the Hundred Talents Program of the Chinese Academy of Sciences(Y20245YBR1)
文摘Carbon quantum dots（CQDs） have emerged as a new generation of photoluminescent nanomaterials with wide applications.Among the various synthetic routes for CQDs,the acid-refluxing method,which belongs to the group of ＂top-down＂ methods,offers the advantage of large-scale production of CQDs and uses cheap and abundantly available starting materials.In this study,we evaluated the potential of fullerene carbon soot（FCS）,a by-product obtained during the synthesis of fullerene,as the starting material for CQD production.It was found that FCS can be successfully converted to CQDs in high production yield in mixed acids,i.e.,concentrated HNO_3 and H_2SO_4,under mild conditions.The fluorescence quantum yield（0） of the as-produced CQDs is in the range of 3%-5%,which is the highest value for CQDs obtained from ＂top-down＂ methods.Importantly,the CQDs prepared by this method show emission in the yellow range of the visible light,which is advantageous for their various potential applications.Further investigations reveal that the CQDs are highly photostable over a wide pH range and show good resistance against ionic strength and long-term UV irradiation.This further expands their potential use under harsh conditions.
