Uneven distribution of minor metals and migration of isotopes in polymeric material （polypropylene） - originating under certain physical and chemical conditions-could possibly affect the stability and bio-compatibil...Uneven distribution of minor metals and migration of isotopes in polymeric material （polypropylene） - originating under certain physical and chemical conditions-could possibly affect the stability and bio-compatibility of such material. Unusually high levels of embedded surface metal isotopes from migration effects could affect studies such as tissue engineering and biospecific adhesion of cells to polymeric surfaces. There is, therefore, a general need to know the distribution of metal isotopes in such polymeric materials. We have developed an ultrasensitive technique for assessing the isotopic distribution in polymer matrices, and studying migration of metal isotopes. The technique uses laser ablation linked to an ICP-MS instrument. It is semi-quantitative and capable of high-resolution detection over a wide range of elemental levels. Polymers usually contain catalytic residues and other minor metal impurities. Some of the isotopes of these metals migrate to the surface, while others remain embedded deep in the polymeric product. Such unwanted metallic residues and isotopes could be a potential hazard, and ablative laser technology has the ability to study homogeneity of such distributions in the polymer matrix. The aim of this paper, therefore, is to explore the potential of our method for studying isotope migration using suitable polypropylene samples.展开更多
文摘为探索长期连作状态下烟草根系分泌物内含有的化感物质组成成分,设置石英砂栽培和连作土壤栽培2种烟草培养处理,对2种烟草不同生长时期的根系分泌物进行提取,利用超高效液相色谱串联质谱(ultra-high performance liquid chromatography tandem mass spectrometry,UHPLC-MS/MS)对提取的根系分泌物进行分析,通过数据库比对、差异分析和时间聚类分析等方法筛选连作烟草根系分泌物中潜在的化感物质。结果表明,共筛选出11类潜在化感物质,分别为生物碱、萜类、胺类、有机酸、苯酸及其衍生物、脂肪酸、酚类、氨基酸和多肽、香豆素、肉桂酸及其衍生物和其他。生物碱、萜类、胺类和有机酸4类化合物相对含量占所有化合物的73.3%。L-烟碱、熊果酸、β-氨基丙腈、5-羟基吲哚乙酸、早熟素Ⅱ、单乙基己基邻苯二甲酸、己内酰胺、姜酚、L-乳酸、邻苯二甲酸二乙酯和2,3-二氢-3,5-二羟基-2-氧代-3-吲哚乙酸甲酯是连作烟草根系分泌物中相对含量较高的潜在化感物质。研究结果为烟草根系化感物质的化感作用研究及缓解烟草连作障碍方法研究提供理论基础。
文摘Uneven distribution of minor metals and migration of isotopes in polymeric material （polypropylene） - originating under certain physical and chemical conditions-could possibly affect the stability and bio-compatibility of such material. Unusually high levels of embedded surface metal isotopes from migration effects could affect studies such as tissue engineering and biospecific adhesion of cells to polymeric surfaces. There is, therefore, a general need to know the distribution of metal isotopes in such polymeric materials. We have developed an ultrasensitive technique for assessing the isotopic distribution in polymer matrices, and studying migration of metal isotopes. The technique uses laser ablation linked to an ICP-MS instrument. It is semi-quantitative and capable of high-resolution detection over a wide range of elemental levels. Polymers usually contain catalytic residues and other minor metal impurities. Some of the isotopes of these metals migrate to the surface, while others remain embedded deep in the polymeric product. Such unwanted metallic residues and isotopes could be a potential hazard, and ablative laser technology has the ability to study homogeneity of such distributions in the polymer matrix. The aim of this paper, therefore, is to explore the potential of our method for studying isotope migration using suitable polypropylene samples.
