毛细管气相色谱法测定热不稳定有机磷农药辛硫磷

The thermo-labile organophosphorous pesticide Phoxim was determined by capillary gas chromatographywith flame phototnetric detector. When high linear velocity H_2(>200cm/s) was used as carrier gas,the thermo-decomposition of Phoxim was considerably reduced.The most important gas chromatography conditions,injectortempereture and column head pressure,were studied.The thermo-decomposition preducts were identified by gaschromatography-mass spectrometry.     

用氢为载气的氢火焰检测器进行多种农药制剂的气相色谱分析

探讨了用氢为载气的氢火焰离子化检测器,进行多种农药制剂气相色谱分析时的优点。分别使用５％ＳＥ－３０／ＣｈｒｏｍｏｓｏｒｂＧＡＷＤＭＣＳ填充的１ｍ×３ｍｍｉ．ｄ．玻璃柱,ＳＥ－３０的１２ｍ×０．３２ｍｉ．ｄ．石英毛细管柱进行试验,已成功地应用于十一种有机磷杀虫刑、五种氢基甲酸酯杀虫剂和八种拟除虫菊酯的测定。     

[Ir(COD)(diphos)Cl配合物活化sp^3 C-H键及其促进CO、CO2插入Ir-C键反应性能的研究

本文利用[Ir(COD)(μ-Cl)]2与双膦螯合配位体之间的反应合成了三个新的配合物[Ir(COD)(diphos)]Cl(diphos=dmpe、depe、dppe),用IR、NMR、电导和元素分析测定了结构.以CH3CN为反应底物分别考察了它们活化sp^3C-H键的能力及其反应规律.在此基础上进一步研究了使CO、CO2插入生成的Ir-CH2CN键的可能性.结果表明:在温和条件下进行这一插入反应是可能的,并用光谱方法证实有相应的含羰基、羧基的金属配合物的生成.     

有机磷化合物的研究 X:五价膦(磷)酸酯与卤代烷在卤化钠存在下的酯烷基交换反应

A detailed study on the ester alkyl exchange reaction of various types of quinique-valent phosphorus esters with alkyl halide in the presence of sodium bromides was reported. This ester alkyl exchange reaction was evidently influenced by the structure of phosphorus esters and alkyl halides as well as by the nature of the halides of metal ions. In contrast with the reaction without sodium hadlide, the alkyl phosphinmate is more reactive than phosphonate and phosphate by treatment with alkyl halide in the presence of sodium halide. This is consistent with the high nucleophilicity of >P(CO)O- as leaving group. The reactivity of butyl halides was decreased in the following order: n-BuBr>i-BuBr=s-BuBr>t-BuBr. Alkyl iodide was proved to be more reactive than the corresponding bromide and chloride. However, the use of iodioe is limited by the formation of alkene resulted from the elimination of HI. These structural effects show the general characteristics of a nucleophilic substitution reaction. A reaction mechanism involving the formation of sodium salt intermecutiate was proposed based on the concept of HSAB principle. This reaction may, however, be used as a convenient method for the preparation of mixed esters of quinque-valent phosphorus acids.     

全自动凝胶净化-浓缩-固相萃取/气相色谱-质谱法测定紫皮石斛中有机磷农药残留

建立了以凝胶渗透色谱(GPC)和固相萃取(SPE)净化、气相色谱-质谱(GC-MS)法同时测定紫皮石斛中10种有机磷农药残留的方法。样品用乙腈超声提取,提取液经GPC去除类脂杂质和大分子物质,后经Envi-Carb/NH2固相萃取柱净化,选择离子(SIM)监测模式检测,外标法定量。在26min内10种农药得到很好的分离,农药残留量在0.02~0.5μg/mL,方法的线性良好,相关系数为0.997 3~0.999 9,农药加标浓度为0.05mg/kg和0.2mg/kg时,加标回收率在70.4%~115.8%,相对标准偏差在2.8%~9.6%,满足国家标准要求,检出限为0.005 2~0.011mg/kg。方法简便、快速、灵敏、准确,能够运用于石斛中多组分有机磷农药残留的定性和定量分析。     

气相色谱法同时测定果蔬中常见有机磷农药残留量

利用气相色谱法测定食品中7种常见的有机磷农药残留量,优化提取条件、载气流速等实验条件,在样品提取时采用超声波法,乙腈作为提取体系,提高农药的萃取效率。经气相色谱法测定,外标法定量,结果表明,本方法在0.05μg·mL~(-1)～10.0μg·mL~(-1)浓度内有较好的线性关系,该方法对甲拌磷、乙拌磷、甲基对硫磷、马拉硫磷、喹硫磷、杀扑磷、毒死蜱七种有机磷农药有较好的分离效果,检出限范围为0.04μg·L~(-1)～0.12μg·L~(-1),在固定加标量的条件下,方法的回收率范围为81%～99.6%,相对标准偏差低于10%,符合分析方法要求。该方法可用于蔬菜水果中7种有机磷农药残留的同时测定。     

中药中有机磷农药残留量的毛细管气相色谱测定方法

建立了中药中多种有机磷农药残留量的毛细管气相色谱测定方法，样品以丙酮一石油醚(1 2)混合溶剂为提取剂，应用超声波提取，固相吸附层析柱净化(弗罗里硅土和中性氧化铝2：1)，采用GC—FPD法同时测定中药中多种有机磷农药残留量，检测限浓度为0．011-0．017μg／mL方法回收率为84.5％-108．9％。该法简便、准确，能满足实际样品分析。