在解析特殊挥发性物质的质谱裂解行为的基础上,建立气相色谱-质谱联用单离子监测(gas chromatography-mass spectrometry with selected ion monitoring,GC-MS SIM)稳定同位素内标法,对不同品种葡萄果实中的58种挥发性物质进行精准的定...在解析特殊挥发性物质的质谱裂解行为的基础上,建立气相色谱-质谱联用单离子监测(gas chromatography-mass spectrometry with selected ion monitoring,GC-MS SIM)稳定同位素内标法,对不同品种葡萄果实中的58种挥发性物质进行精准的定性与定量分析,并探讨不同品种中挥发性物质的含量差异。葡萄果实样品破碎均质后,采用固相微萃取的方法进行高效富集萃取,再进行GC-MS SIM分析。结果表明,在特定的质量浓度范围内该方法线性关系良好,其线性相关系数在0.995 0(除异丙醇为0.967 1)以上;绝大多数目标物的检出限低于1.56μg/kg;除个别挥发性物质的加标回收率较低,不同加标水平目标物样品回收率在60.64%~129.63%范围内,其回收率结果的相对标准偏差均低于19.56%。该方法具有灵敏度高、准确可靠的优点,适用于葡萄等水果蔬菜中挥发性物质的准确定性与定量研究。此外,本实验通过对12个不同品种的葡萄果实样品中挥发性物质的差异分析,探明葡萄果实中的关键性挥发性物质,并挖掘出不同品种葡萄的特色挥发性物质。展开更多
A novel preparation method of phosphorus pentafluoride（PF5） is introduced in details in the article. Phosphorus pentafluoride is mainly used to synthesize lithium ion battery electrolyte salt. In the experiment mesn...A novel preparation method of phosphorus pentafluoride（PF5） is introduced in details in the article. Phosphorus pentafluoride is mainly used to synthesize lithium ion battery electrolyte salt. In the experiment mesneproduct- hexafluorophosphoric acid（HPF6） was firstly prepared-from phosphorus pentoxide（P2O5） and anhydrous hydrogen fluoride（HF）, according to the chemical stoichiometrics, the optimum amount of excess HF used was about 60% and the optimum reaction time was 4 h; then HPF6 was dehydrated by oleum with an excess amount of 35%-- 40% which was heated for 40--50 min at 150 ℃; thus HPF6 was decomposed to a mixture of gases containing PF5; impurity gases were removed through condensation in the presence of cooling water at 0 ℃, then PF5 of high purity was eventually prepared. The production was characterized by inffared（IR） spectrometry and gas chromatography-mass spectroscopy-selected ion monitoring（GC-MS-SIM）. Eventual results indicate that PF5 prepared by the novel method has a high target purity and a low amount of impurity and water.展开更多
基金Supported by the National Basic Research Program of China(No.2007CB613607)
文摘A novel preparation method of phosphorus pentafluoride（PF5） is introduced in details in the article. Phosphorus pentafluoride is mainly used to synthesize lithium ion battery electrolyte salt. In the experiment mesneproduct- hexafluorophosphoric acid（HPF6） was firstly prepared-from phosphorus pentoxide（P2O5） and anhydrous hydrogen fluoride（HF）, according to the chemical stoichiometrics, the optimum amount of excess HF used was about 60% and the optimum reaction time was 4 h; then HPF6 was dehydrated by oleum with an excess amount of 35%-- 40% which was heated for 40--50 min at 150 ℃; thus HPF6 was decomposed to a mixture of gases containing PF5; impurity gases were removed through condensation in the presence of cooling water at 0 ℃, then PF5 of high purity was eventually prepared. The production was characterized by inffared（IR） spectrometry and gas chromatography-mass spectroscopy-selected ion monitoring（GC-MS-SIM）. Eventual results indicate that PF5 prepared by the novel method has a high target purity and a low amount of impurity and water.
