气相色谱-电子捕获检测器同时测定硝基咪唑类药物

建立了气相色谱-电子捕获检测器同时测定硝基咪唑类药物含量的方法.样品用磷酸盐调节pH约为8.8,乙酸乙酯提取,无水硫酸钠脱水.采用CBP-1毛细管柱分离,电子捕获检测器检测.甲硝唑、替硝唑、奥硝唑分别在0.2～15 μg/mL、5.3～53μg/mL、4.0～40μg/mL范围内与峰面积呈良好线性关系,相关系数r分别为0.9993、0.9996、0.9995.样品加标回收率在95.8%～101%之间,相对标准偏差在1.8%～3.4%之间.本法简便、快速,可用于片剂和注射液中硝基咪唑类药物含量的测定.     

顶空气相色谱法测定盐酸托莫西汀中有机溶剂残留量的研究

建立了盐酸托莫西汀中有机溶剂残留量的顶空气相色谱分析方法.选用大口径HP-快速GC残留溶剂柱为分离柱,FID为检测器,外标法进行定量,并对顶空平衡温度、平衡时间、供试品溶液的制备方法对残留有机溶剂测定的影响进行了研究.甲醇、乙醚、正己烷、乙酸乙酯、四氢呋喃的线性范围分别为 0.41～8.10 μg/mL(r=0.9999)、0.15～3.00 μg/mL(r=0.9995)、0.20～4.01 μg/mL(r=0.9991)、0.32～6.35 μg/mL(r=0.9999)、0.36～7.11 μg/mL(r=0.9999);平均回收率范围96.30%～105.47%,精密度RSD(n=6)2.1%～3.7%;检出限分别为0.2、0.008、0.003、0.04、0.04 μg/mL.     

化妆品中氯霉素的气相色谱-质谱快速分析

研究了用气相色谱-质谱分析化妆品中氯霉素(CAP)的方法.以乙酸乙酯作为提取溶剂,BSTFA TMCS(99 1)作为衍生化试剂,在70℃衍生化60min,用GC-MS(NCI)进行测定.方法的检出限为10 μg/kg,线性范围在0.5～500 ng/mL之间,在10、100、500 μg/kg 3个添加水平,方法回收率为94.4%～95.7%,相对标准偏差为0.23%～1.3%.方法操作快速简单,3 h可以完成整个样品分析.方法已用于化妆品中氯霉素的测定.     

吹扫捕集-气相色谱-质谱法测定土壤中乙酸乙酯和丙烯酸乙酯

建立吹扫捕集-气相色谱-质谱法测定土壤中乙酸乙酯和丙烯酸乙酯的方法。称量5 g土壤样品于40 mL吹扫瓶中,加入5 mL超纯水进行吹扫捕集提取,用DB-624毛细管色谱柱（60 m×250μm,1.4μm）分离,全扫描后进行谱库检索定性,内标法定量。乙酸乙酯和丙烯酸乙酯的质量浓度在5.0～200μg/L范围内与定量离子与内标定量离子色谱峰面积的比值线性关系良好,相关系数分别为0.999 6和0.999 2,检出限分别为1.2、1.4μg/kg。样品加标平均回收率分别为95.8%～108%,79.9%～98.0%,测定结果的相对标准偏差分别为1.92%～13.7%、2.05%～13.8%(n=6)。该方法可用于土壤中乙酸乙酯和丙烯酸乙酯的测定。     

快速溶剂萃取-气相色谱-串联质谱法测定血中巴比妥类药物

提出了气相色谱-串联质谱法测定血中巴比妥类药物(巴比妥、苯巴比妥、异戊巴比妥、司可巴比妥)含量的方法。样品以乙酸乙酯-环己烷(1+1)混合液为萃取剂,经快速溶剂萃取仪提取后,提取液用氮气吹干后以1.0mL甲醇溶解,通过VF-5MS色谱柱分离,采用电子轰击离子源多反应监测模式进行质谱测定。4种巴比妥类药物的质量浓度与其峰面积均在10～1 000μg.L-1之间呈线性关系,检出限(3S/N)在0.07～0.26μg.L-1之间。以空白血液样品为基体进行回收试验,测得回收率在77.8%～93.4%之间,测定值的相对标准偏差(n=7)在2.3%～6.9%之间。     

气相色谱法快速同时测定室内装饰装修材料胶黏剂中的苯、甲苯、二甲苯的含量

建立了快速、同时测定室内装饰装修材料胶黏剂中苯、甲苯、二甲苯含量的气相色谱检测法.样品用乙酸乙酯溶解处理后,用改性的聚乙二醇(FFAP)毛细管色谱柱分离,氢火焰离子化检测器检测,外标法定量.胶粘剂中苯、甲苯、二甲苯的浓度分别在8.58～171.40μg/mL、9.04～180.62μg/mL、8.80～175.92μg...     

HPLC／UV法对银鲫肌肉组织中甲苯咪唑及其代谢产物残留的同时测定

建立了一种用高效液相色谱同时测定银鲫肌肉组织中甲苯咪唑(MBZ)及其代谢物氨基甲苯咪唑和羟基甲苯咪唑的方法.银鲫肌肉组织用乙酸乙酯提取,萃取物旋转蒸发至干后用1 mL二甲基甲酰胺-0.05 mol/L磷酸盐缓冲液(体积比3 ∶ 7)定容.色谱条件:Waters symmetry C18反相色谱柱(250 mm×4.6 mm,5 μm);流动相:乙腈-0.05 mol/L磷酸二氢铵溶液(体积比33 ∶ 67);流速:0.8 mL/min;检测波长为298 nm;检测温度为室温.在10 ～120 μg/kg添加水平,MBZ、MBZ-NH2、MBZ-OH的回收率分别为81% ～86%、71% ～75%、86% ～93%.MBZ的检出限为2 μg/kg,MBZ-OH和MBZ-NH2检出限均为3 μg/kg.     

海产品中残留三唑磷的GC/MS分析

建立了海产品中残留三唑磷农药的毛细管气相色谱-质谱联用检测法.向冷冻干燥后的样品中加入邻苯二甲酸二戊酯作为定量内标,用乙酸乙酯正己烷(11 V/V)提取,浓缩定容后用EI源在SIM检测模式下进行检测.结果表明,三唑磷与内标在SBP-50柱上得到良好的分离,色谱出峰尖锐,没有杂峰干扰.方法在2.5～50 ng/mL浓度范围内线性关系良好,线性方程为Y=8.261×10-4x,相关系数为0.9998.方法的最低检测限低于0.3 ng/mL.当向1.00g样品中添加三唑磷10～500 ng/mL时,平均回收率分别达到95.6%～100.1%,标准相对偏差为2.37%～3.55%.对采自浙江沿海几种海产品测定,三唑磷含量在0～1.34 ng/g范围内.     

高效液相色谱测定肉制食品中五种邻苯二甲酸酯

建立了肉制食品中5种邻苯二甲酸酯类增塑剂(PAEs)含量的检测方法.样品用正己烷提取,C18柱分离,柱温35.0℃,乙腈.水为流动相梯度洗脱,流速1.0 mL/min,紫外检测波长226 nm.5种PAEs分离特异性好,在0.02～10μg/mL之间均具有较好的线性关系,检出限在4.4～13.8 ng/mL之间,高、中、低3水平的回收率均在79.5%～102.0%之间,相对标准偏差均在1.1%～14%之间.方法适用于肉制食品中邻苯二甲酸酯类的检测.     

顶空气相色谱法同时测定新药CBT108中12种残留溶剂

采用顶空气相色谱技术,建立了同时测定新药CBT108中12种残留溶剂的方法。优化了平衡加热时间和程序升温时间以及制样的溶剂,并通过验证确定了本方法的合理性、准确性和可行性。在优化的实验条件下,采用DB-624型毛细管柱(6%氰丙基苯基-94%二甲基聚硅氧烷为固定液,30 m×0.53 mm×3.0μm)分离、氢火焰离子化检测器检测、内标法定量的分析方案,实现了甲醇、乙醇、乙醚、丙酮、乙腈、二氯甲烷、正己烷、乙酸乙酯、四氢呋喃、庚烷、甲苯和四氯化碳共12种残留溶剂的同时分离与测定。12种溶剂在各自的范围内线性关系良好,线性相关系数(R~2)均0.997;以10倍信噪比确定方法定量限,以3倍信噪比确定方法检出限,分别为:甲醇0.024μg/mL、0.0072μg/mL;乙醇0.1μg/mL、0.012μg/mL;乙醚0.01μg/mL、0.005μg/mL;丙酮0.1μg/mL、0.008μg/mL;乙腈1.025μg/mL、0.0615μg/mL;二氯甲烷0.09μg/mL、0.06μg/mL;正己烷0.0174μg/mL、0.0145μg/mL;乙酸乙酯0.25μg/mL、0.008μg/mL;四氢呋喃0.108μg/mL、0.014μg/mL;四氯化碳0.16μg/mL、0.0004μg/mL;庚烷0.0075μg/mL、0.005μg/mL;甲苯0.0445μg/mL、0.0014μg/mL。在3个添加水平下,12种残留溶剂的加标回收率在90.96%~108.67%之间,相对标准偏差为0.1%~5.7%。结果表明,本法简单、快速、重现性好、准确性高,可用于实际药品中以上12种残留溶剂的检测,并可对其它药物中残留溶剂的检测提供参考。     

醋酸铈及醋酸稀土的研制工艺

研究了醋酸铈及醋酸稀土的研制工艺. 分析了醋酸浓度、反应温度、醋酸与碳酸铈固液比、保温时间对碳酸铈溶解收率的影响. 确定了碳酸铈的最佳溶解工艺条件. 在此条件下研制了晶型醋酸铈, 混合醋酸稀土(La, Ce, Pr, Nd)(Ac)3, (Ce, Pr, Nd)(Ac)3,(Pr, Nd, Er, Y)(Ac)3及醋酸钇. 用扫描电镜、热重-差热分析、 X射线粉末衍射分析及化学分析等方法考察了上述晶体的形貌、结构和组成.     

A Bioelectrochemical Method for the Determination of Acetate with Immobilized Acetate Kinase

Abstract

Flow injection determinations of acetate were carried out using immobilized acetate kinase, pyruvate kinase and lactic dehydrogenase with an amperometric method. Two acetate kinases from E. coli and B. stearothermophilus were tested. It was found that the immobilized acetate kinase from B. stearothermophilus was more stable than that from E. coli., but it is much more expensive and less available. Acetate kinase coupling at pH 7.4 using CPG aminopropyl and glutaraldehyde seems to be superior to other immobilization methods. A high immobilization yield can be obtained by immobilization of the three enzymes separately giving high conversions of all the three. Plots of current versus concentration show a useful operating range from 0.3 to 2 mM acetate with a linear response. The detection limit was 0.2 mM at a flow rate of 0.3 ml/min with 200 μl injections. The method is therefore well suited for monitoring of the level of acetate in fermentations with acetate as the carbon source.     

糠偶姻乙酸酯的合成

在碱金属盐存在下,由糠偶姻与乙酸酐酯化为糠偶姻乙酸酯,收率９４％～９８％,ｍ．ｐ．６８℃～６９℃,并通过元素分析和红外光谱进行表征。     

Acid-Catalyzed Methanolysis of Vinyl Acetate Polymers and Copolymers. I. Polyvinyl Acetate

Acid (HCL) catalyzed methanolysis of polyvinyl acetate and of model compounds was carried out in solvent mixtures with various amounts of methanol and tetrahydrofuran. The initial rate was first order vs methanol concentration. The acceleration was mainly dependent on the extension of the chain and was enhanced by a tighter coiling of the macromolecule; it is suggested that coiling favors the trapping of the catalyst ions.     

Acoustical Properties of Binary Mixtures of Heptane with Ethyl Acetate or Butyl Acetate

Mixed solvents rather than single pure liquids are of utmost practical importance in chemical and industrial processes as they provide an ample opportunity for the continuous adjustment of desired properties of the medium. Therefore, ultrasonic velocity (u) and density (ρ) were measured for the binary mixtures formed by heptane with ethyl acetate or butyl acetate at temperatures 293, 298 and 303 K over the entire composition range. Deviation in ultrasonic velocity (Δu), deviation in isentropic compressibility (Δκ_s), and excess intermolecular free length (L^E_f) have been evaluated using the ultrasonic velocity data and the computed results were fitted to the Redlich‐Kister polynomial equation. The values of Δu, Δκ_s and L^E_f were plotted against the molar fraction of heptane. The observed positive and negative values of excess parameters were discussed in terms of molecular interaction between the components of the mixtures. Experimental values of ultrasonic velocity and density were compared with the results obtained by theoretical estimation procedures. The results were discussed in terms of average absolute deviation (AAD).     

制备乙酸乙酯实验的改进

我对新编高级中学课本化学（必修）第二册［实验5—7］中制取乙酸乙酯的实验装置作了改进,并用灯用酒精和37％醋酸代替无水乙醇和冰醋酸,实验效果良好,药品价廉易得,操作简便安全,更适合学生。     

Gasförmige Acetate

Gaseous Acetates Thermoanalytical and mass-spectrometrical observations are undertaken with some acetates and oxiacetates. The volatilization of copper(I) acetate takes place like that of the silver acetate as M₂Ac₂⁺ (besides the deposition of Ag). On the volatilization of the anhydrous compounds Cu₂Ac₄, Cr₂Ac₄, Rh₂Ac₄, and Mo₂Ac₄ in the vacuum of a mass spectrometer is observed that Cu₂Ac₄ vaporizes dissociative as Cu₂Ac₂⁺ (+ 2 “Ac”), while the other compounds vaporize as M₂Ac₄⁺ and simultaneously is formed an oxidic (e.g. Cr₂O₄) or metallic residue. PdAc₂ vaporizes in the mass spectrometer as a trimeric molecule Pd₃Ac₆. M₄OAc₆, which is formed from the dihydrates, vaporizes in a mass spectrometer with M ? Co, Mn as M₄OAc₆⁺. Other complexes of the same type appear as Be₄OAc₅⁺, Mg₄OAc₅⁺, and Zn₄OAc₅⁺.