GC法测定瑞草油中四组分与鉴别桉油

以GC法测定瑞草油各组分时,采用20% PEG-20 M固定相,正葵醇为内标,柱温以每min 4℃从170℃升至210℃。四组分的方法回收率、变异系数(n=5)、及其线性浓度范围分别为:樟脑97.44±1.04%、9.0～130mg/mL;薄荷脑99.68±0.97%、28.0～40.0 mg/mL;水杨酸甲酯97.16±0.48%、4.0～6.0 mg/mL;水杨酸乙酯100.44±1.13%、4.0～6.0 mg/mL。经测定三批样品的结果表明,本法具有操作简单、快捷、准确等优点。     

Adsorption of Oil Substances by Carbon Monolith and Their Subsequent Determination by GC/GC/MS

Moscow University Chemistry Bulletin - A monolith based on foamed graphite is used for the sorption of hydrocarbons (alkanes, cycloalkanes, arenes) as markers of oil pollution. This material is...     

环氧蓖麻油合成条件优化

在无溶剂条件下制备环氧蓖麻油,对参加环氧化反应的有机酸和催化剂进行选择,研究了反应时间和反应温度对产物环氧值的影响。通过正交实验对环氧化合成条件进行优化,结果表明,蓖麻油／乙酸／双氧水／磷酸（质量比）=1：0．15：0．8：0．01,反应温度50℃,反应时间3h,所得产品环氧值达6．95％,采用FT-IR和1HNMR方法对产品进行了表征。整个过程操作简单,反应时间短,反应条件温和。     

反气相色谱法测定苯乙烯-氧乙烯-苯乙烯三嵌段聚合物的表面能

 采用反气相色谱法测定了苯乙烯 氧乙烯 苯乙烯三嵌段聚合物 (PS PEO PS)的色散成分的表面能 (γsd) ,研究探讨了温度及嵌段聚合物链段结构组成对γsd 的影响 ,并确定了γsd 与温度的数学关系式。研究结果表明 :在 70℃～ 12 0℃范围内 ,PS PEO PS的表面能较低 ;随着PS PEO PS表面组成中氧乙烯 (EO)成分的增加 ,色散成分的γsd 增大 ,且对温度的变化极其敏感 :随温度的升高 ,γsd 急剧地呈线性下降。     

Thermal,Rheological and Mechanical Properties of Biodegradable Poly(propylene carbonate)/Epoxidized Soybean Oil Blends

Biodegradable poly(propylene carbonate)(PPC)/epoxidized soybean oil(ESO) blends with different component ratios were prepared by melt blending to improve the performance of PPC. The phase morphology, thermal properties, rheological properties and mechanical properties of the blends were investigated in detail. SEM examination revealed good interfacial adhesion between PPC matrix and ESO.According to DSC and DMA, as the content of ESO increased, the glass transition temperature of the PPC compone...     

Determination of Organophosphorus Pesticides in Soybean Oil, Peanut Oil and Sesame Oil by Low-Temperature Extraction and GC-FPD

A low-temperature clean-up method for residue determination was developed and validated for 14 organophosphorus pesticides in soybean oil, peanut oil and sesame oil by gas chromatography with flame photometric detector (GC-FPD). A different matrix influenced the response and retention time of pesticides. Hence matrix-matched calibration standards were used to counteract the matrix effect. The pesticide responses in blank samples of soybean oil, peanut oil and sesame oil were within the linear range of 0.02–1 mg kg⁻¹ and the correlation coefficients were higher than 0.9989. Average recoveries obtained from different oil samples at three fortified levels were higher than 50% with relative standard deviations (RSDs) of less than 15%. The limit of detections (LODs) of studied pesticides ranged from 2 to 5 μg kg⁻¹. Thirty-nine commercial samples were analyzed, and the results were confirmed by gas chromatography–mass spectrometry (GC–MS) in selective ion monitoring (SIM) mode.     

吐鲁浸膏中精油化学成分的GC-MS分析

利用挥发油提取器测定了吐鲁浸膏的精油含量,用GC-MS分析了浸膏清油的化学成分,鉴定出17种化合物,并采用GC峰面积归一化法定量,探讨了主要成分定量分析的重现性;该法简便、快捷,适用于工厂的浸膏类香料的质量监控和常规分析。     

蒸馏/气相色谱法测定顺丁烯二酸酐生产过程溶剂中非洗提焦油的含量

邻苯二甲酸二丁酯作为顺丁烯二酸酐生产过程中的溶剂,经过一段时间使用后,其中会产生焦油高分子聚合物,它会影响溶剂的使用效率.将溶剂样品经减压蒸馏浓缩后,加入内标物丁二腈,在气相色谱仪中测得其中的邻苯二甲酸酐和邻苯二甲酸二丁酯的质量百分含量,浓缩物中去掉邻苯二甲酸酐和邻苯二甲酸二丁酯含量的剩余物即为样品中的焦油.     

Simultaneous Determination of Oil and Water in Soybean by LF-NMR Relaxometry and Chemometrics

A fast, non-destructive and eco-friendly method was developed to simultaneously determine the oil and water contents of soybean based on low field nuclear magnetic resonance(LF-NMR) relaxometry combined with chemometrics, such as partial least squares regression(PLSR). The Carr-Purcell-Meiboom-Gill(CPMG) magnetization decay data of ten soybean samples were acquired by LF-NMR and directly applied to the PLSR analysis. Calibration models were established via PLSR with full cross-validation based on the reference values obtained by the Soxhlet extraction method for measuring oil and oven-drying method for measuring water. The results indicate that the calibration models are satisfactory for both oil and water determinations; the root mean squared errors of cross-validation(RMSECV) for oil and water are 0.2285% and 0.0178%, respectively. Furthermore, the oil and water contents in unknown soybean samples were predicted by the PLSR models and the results were compared with the reference values. The relative errors of the predicted oil and water contents were in ranges of 1.25%-4.96% and 0.44%-2.49%, respectively. These results demonstrate that the combination of LF-NMR relaxometry with chemometrics shows great potential for the simultaneous determination of contents of oil and water in soybean with high accuracy.     

Synthesis and Thermal Properties of Epoxidized Vegetable Oil

Summary: The novel potential epoxy resins, epoxidized soybean oil (ESO) and epoxidized castor oil (ECO), were synthesized and characterized. The cationic polymerization of ESO and ECO with a latent thermal catalyst, N‐benzylpyrazinium hexafluoroantimonate (BPH), was initiated at 80 and 50 °C, respectively. The cured ECO samples showed a higher T_g and lower coefficient of thermal expansion than those of ESO, due to the higher intermolecular interaction in the ECO/BPH system.

Relationships between ESO or ECO conversion and temperature in the polymerization with 1 wt.‐% BPH for 2 h.     

环氧化蓖麻油的合成及表征

采用酸性氧化铝做催化剂对蓖麻油(CO)进行环氧化,探索环氧化反应时间、反应温度和催化剂等不同条件对蓖麻油环氧化的影响,从而优化出合适的反应条件,采用傅立叶变换红外光谱法(FTIR)、热重分析法(TG)对制备的环氧化蓖麻油(ECO)的结构和性质等进行了研究。利用盐酸-丙酮法对环氧化产物进行环氧值的测定,结果表明,在优化条件下,即采用酸性氧化铝做催化剂,H₂O₂的滴加温度保持在50～55 ℃,反应温度65 ℃,反应时间控制在11.5 h,同时同时加入尿素做稳定剂,可以提高H₂O₂的利用率,使环氧化蓖麻油的环氧值达到2.094×10_-3 mol/g。 对ECO的性能表征结果表明,ECO粘度随着环氧值的增大而增大,随着温度的升高而降低。 ECO在250 ℃前能够基本保持稳定,而后开始分解,有3个明显的热分解阶段：250~390 ℃、390~470 ℃、470~580 ℃,ECO的热稳定性较好。     

Synthesis and Characterization of Acrylated Epoxidized Castor Oil Nanocomposites

Renewable resource-based epoxidized castor oil (ECO) was synthesized and used as a prime material to develop acrylated epoxidized castor oil (AECO) networks. AECO nanocomposites were prepared by the sol-gel method from organo-modified montmorillonite (OMMT) clay and silane. It was found that the AECO/1 wt.% OMMT system increased in tensile strength from 28 to 37 MPa and flexural strength from 54 to 63 MPa as compared with the AECO system. The non-isothermal cure kinetics of the bio-based systems was studied using differential scanning calorimetry. The activation energy of the AECO/OMMT system obtained from Kissinger and Flynn-Wall-Ozawa models is lower than that of AECO system.     

大豆含油率分析测定方法的改进

大豆是含高油脂、高蛋白的重要农产品。通常对大豆的含油率测定是采用乙醚作为溶剂，通过索氏(Soxhlet)油脂抽提器测定，一次只能测定一个样品，而且需要近一天时间，操作麻烦。本法在传统方法的基础上，进行研究和改进，试验出大豆含油率的测定新方法。     

海洛因致死案例的司法鉴定

海洛因是我国乃至世界上吸食量最大的毒品之一。随着其滥用状况的恶化,我国因吸食过量而死亡的案例时有发生,因此,从法庭科学角度对其进行鉴定的工作越来越受到广泛的重视。文献[1,2]报道了这方面的工作,本文采用水解和衍生化的方法对一例吸毒死亡案件进行了鉴定,证实了其主体因吸食海洛因过量而致死的事实。     

液液萃取-气相色谱法测定地表水中10种硝基苯类化合物

将水样(200mL)用正己烷(10mL)萃取,所得萃取液经无水硫酸钠干燥后供气相色谱分析。用DB-1701色谱柱,温度在110℃～210℃区间采用程序升温方式进行分离,用电子捕获检测器测定。10种硝基苯类化合物的峰面积与对应的质量浓度在一定范围内呈线性关系,检出限在0.10～2.5μg.L-1之间。用标准加入法测得10种硝基苯类化合物的回收率在86.4%～96.2%之间,测定值的相对标准偏差(n=7)均小于5%。     

Surface Characterization of Sepiolite by Inverse Gas Chromatography

Inverse gas chromatography (IGC) was applied to characterize the surface of sepiolite. The adsorption thermodynamic parameters (the standard enthalpy (ΔH ⁰), entropy (ΔS ⁰) and free energy of adsorption (ΔG ⁰)), the dispersive component of the surface energy (γ _S ^d ), and the acid/base character of sepiolite surface were estimated by using the retention time of different non-polar and polar probes at infinite dilution region. The specific free energy of adsorption (ΔG ^sp ), the specific enthalpy of adsorption (ΔH ^sp ), and the specific entropy of adsorption (ΔS ^sp ) of polar probes on sepiolite were determined. ΔH ^sp were correlated with the donor and modified acceptor numbers of the probes to quantify the acidic K _A and the basic K _D parameters of the sepiolite surface. The values obtained for the parameters K _A and K _D indicated an acidic character for sepiolite surface.     

Phase Transition Behavior of a New Monotropic Liquid Crystal by Inverse GC

A new monotropic liquid crystal with crown ether substituent called Substance M was synthetized and characterized by several methods: ¹H NMR, hot stage polarizing microscopy, differential scanning calorimetry and inverse gas chromatography. Annealing experiments with inverse gas chromatography confirmed the monotropic behavior of the compound. Isothermally in the nematic state, solute probes chosen were chromatographed after different heating times. The changes of the corresponding retention times were studied.     

气相色谱法测定姜味草挥发油中橙花醛与香叶醛

采用水蒸气蒸馏法提取姜味草挥发油,用气相色谱法-氢火焰离子化检测器测定挥发油中橙花醛和香叶醛的含量。橙花醛和香叶醛的线性范围分别为0.0971～0.5826g·L~（-1）和0.1152～0.6912g·L~（-1）方法用于测定4批次姜味草挥发油中橙花醛与香叶醛的含量,橙花醛与香叶醛的质量分数分别为25.00%,29....