气相色谱-质谱法测定洋葱中129种农药残留

建立了组合柱固相萃取-气相色谱-质谱法快速测定洋葱中129种农药残留的分析方法。样品用乙腈均质提取,盐析分配,提取液经C18和PSA组合柱固相萃取净化后供气相色谱-质谱仪(GC-MS)分析。采用选择离子扫描方式,外标法定量。该方法简便、快速,通过优化前处理和上机条件,在最优条件下进行测试,方法的定量下限(S/N≥10)为0.01~0.1 mg/kg,在加标水平为0.1 mg/kg时,方法回收率为63.2%~113.1%,相对标准偏差为5.3%~14.4%。     

QuEChERS提取-气相色谱法测定木棉花中有机磷类残留

建立同时测定木棉花中9种有机磷农药的Qu ECh ERS提取-气相色谱快速检测方法。样品经乙腈溶解,Qu ECh ERS试剂萃取,分散固相萃取净化后,气相色谱-火焰光度检测器检测,在优化条件下,结果显示:9种农药均具有良好的线性关系,相关系数不低于0.995,检出限为0.012~0.316mg/kg,加标回收率为81.6%~103.4%,相对标准偏差为1.6%~4.8%。该方法具有检测结果准确可靠、简便快速等优点。     

分散固相散萃取_气相色谱法测定鱼肉中9种有机磷农药残留

建立了同时检测鱼肉中9种有机磷类农药残留的分散固相萃取-气相色谱联用方法。样品经乙腈进行提取,PSA、GCB和C18进行分散固相萃取净化,结合气相色谱法定性定量分析。添加样品的回收率为70.1%~80.4%,相对标准偏差在5.0%~10.2%,方法最低检出限为0.005~0.01 mg/kg。该法简便、准确,适用于鱼肉中9种有机磷农药残留量的检测。     

顶空固相微萃取-气相色谱/质谱法结合保留指数法测定龙井茶的香气成分

采用顶空固相微萃取(headspace solid phase micro-extraction,HS-SPME)和气相色谱-质谱(gas chromatographymass spectrometry,GC-MS)结合保留指数法分析龙井中的挥发性成分。以茶叶香气成分的种类和数量为参照,考察HS-SPME的最佳萃取条件;同时优化色谱分离条件;利用优化的HS-SPME-GC/MS条件分析龙井茶中的挥发性成分。结果表明,运用HS-SPME-GC/MS能有效测定龙井茶中的挥发性成分,这些挥发性成分中主要含有醇类(31.14%)、酯类(15.66%)、酮类(10.42%)、杂环类化合物(15.00%)等。顶空固相微萃取-气相色谱质谱法结合保留指数分析是一种快速有效分析龙井茶香气成分的方法,可提高定性分析的准确性和效率,使定性结果更加可靠。该定性分析方法也为其他复杂样品中挥发性成分分析提供参考。     

固相微萃取-气相色谱-质谱法在烟草香味成分分析中的应用

采用固相微萃取-气相色谱-质谱(SPME—GC—MS)法定性分析烟叶和成品烟的挥发性香味成分，共鉴定了烟叶中的29种挥发性成分和成品烟中的20种挥发性成分。该方法简单、快速，适用于烟草样品的定性分析检测。     

固相萃取-气相色谱法测定葡萄酒中16种有机磷农药残留

利用固相萃取(SPE)/气相色谱火焰光度(GC-FPD)技术建立了葡萄酒中16种有机磷农药残留量分析方法。样品加水稀释,过HLB小柱和LC-NH2小柱净化,浓缩、定容后,用气相色谱测定,外标法定量。各农药的方法定量限(LOQ)均为为0.01 mg/kg。添加回收实验,16种有机磷农药添加浓度为0.01-0.10 mg/kg时,添加回收率为65.3-92.3%,变异系数≤10%。     

基于SPME-GC-MS分析卷烟包装材料挥发性气体的研究

目的 建立一种高效且准确的分析测试方法,快速检测卷烟包装材料中挥发性气体的类别和含量.方法 基于气相色谱-质谱联用(GC-MS),比较传统顶空-气相色谱-质谱联用(HS-GC-MS)和固相微萃取-气相色谱-质谱联用(SPME-GC-MS)的检测效果,并对SPME-GC-MS检测的各项参数进行优化.结果 确定了SPME-GC-MS定性、定量分析卷烟材料气味的最优分析条件,并对印刷工艺较为复杂的盒包卷烟包装材料进行了高效、准确的检测.结论 建立的SPME-GC-MS方法可以对盒包卷烟包装材料挥发性气体的异味进行定性和定量分析,为盒包材料的品质评价和印刷过程中异味的检测提供了新的策略.     

荧光检测-高效液相色谱法测定水质中生物胺

本文以常存在于水中的五种生物胺(腐胺PUT.、尸胺CAD.、组胺HIS.、亚精胺SPD.、精胺SPM.)作为分析对象,优化了液相色谱的测定条件(流动相、发射波长、梯度洗脱程序等)、生物胺的衍生条件以及分散液液微萃取的萃取条件,建立了分散液液微萃取-液相色谱-荧光检测技术应用于检测水中五种生物胺残留的方法。     

分散固相萃取-高效液相色谱串联质谱法测定水产品中氯霉素类药物的残留量

本文采用分散固相萃取技术作为前处理手段,结合高效液相色谱串联质谱(HPLC-MS/MS)高灵敏度和高选择性的优势,建立了一种水产品中氯霉素类药物残留的检测方法。实验探讨和优化了以分散固相萃取净化样液过程中的提取条件、固体吸附剂的用量等。并优化检测方法的色谱、质谱条件,采用多反应监测模式(MRM)对目标物进行定性、定量分析。结果表明,目标物在一定的浓度范围内具有良好的线性关系;方法的检出限为0.07～0.10μg·kg~(-1)。对样品进行三个水平加标实验,目标化合物的回收率为88.81%～102.89%,相对标准偏差(RSD,n=6)为2.30%～4.87%。该方法定性定量准确,灵敏度高,有效去除基质干扰,适用于水产品中氯霉素类药物残留量的定性、定量分析。     

固相微萃取-气相色谱联用法在气态物质定值中的应用

固相微萃取是新型样品前处理手段,可与气相色谱法联用,用于测定体系中痕量物质的量。文章以氮气中苯含量的测定为例,介绍固相微萃取-气相色谱联用法定值的一般过程,并对测量结果的不确定度进行评定。通过结果分析可以发现,利用固相微萃取-气相色谱联用法可对体系中痕量有效成分浓度进行测定,此方法在痕量标准物质定值中具有较高的应用价值。     

等规聚丙烯/豆油体系的非等温结晶动力学

采用差示扫描量热仪(DSC)对等规聚丙烯(iPP)与豆油体系的非等温结晶动力学进行了研究,并用扫描电子显微镜(SEM)观察了等规聚丙烯在豆油中的结晶形态．对实验数据用Ziabicki理论和Jeziorny方法进行处理,求出结晶动力学指数、结晶速率常数和结晶能力等数据,分析了降温速率及iPP初始浓度等对结晶动力学参数的影响．     

顶空气相色谱/质谱法分析大豆油中正己醛含量

建立大豆油中正己醛含量的顶空气质分析方法。将大豆油试样放入密封的气化瓶中,在55℃温度下,使正己醛气化达到平衡时,取液上气体注入GC/MS,经非极性毛细管柱HP-5ms分离,质谱选择离子监测对正己醛进行定量测定。该方法在0.05~1.00μg/mL范围内线性关系良好,相关系数0.9997;最小检测限为3.15ng/mL,方法回收率在90.0~107%之间,相对标准偏差3.4%。该方法前处理简单、快速,定量准确,灵敏度高,可用于实验室检测大豆油中正己醛含量。     

不同油相对负载茶多酚的多重乳液稳定性的影响

采用高压均质和高速剪切的方法,观察其制备的初乳对多重乳液稳定性的影响,并研究了大豆油、芥花油、油茶籽油和葵花籽油四种不同的植物油作为油相对多重乳液稳定性的影响,实验结果表明,用高压均质方法制备的初乳能够获得稳定的、外观细腻的多重乳液。四种不同的油相制备的多重乳液在4000r/min,15min的离心条件下不分层;大豆油作为油相制备的多重乳液在室温下放置两个月分层,芥花油、油茶籽油和葵花籽油,在室温下放置三个月不分层。对四种不同油相制备的多重乳液的粒径进行测量,实验结果表明,油茶籽油的D0.1,D0.5和D0.9三个数据的粒径的稳定性比较好。     

Preparation and Evaluation of 2-(Allylthio)Pyrazine-Loaded Lipid Emulsion with Enhanced Stability and Liver Targeting

To develop 2-(allylthio)pyrazine (2-AP)-loaded lipid emulsion for parenteral administration, various lipid emulsions were prepared with soybean oil, lecithin, and other carriers using homogenization method, and their physical stabilities were investigated by measuring their droplet sizes. The pharmacokinetics and tissue distribution of 2-AP in lipid emulsion after intravenous administration to rats were evaluated compared with 2-AP in solution. 2-AP was lipophilic, sparingly water-soluble, and unstable in aqueous medium. The 2-AP-loaded lipid emulsion composed of 1% of 2-AP, 4% of soybean oil, 4% of lecithin, and 91% of water was physically and chemically stable for at least 8 weeks. It gave significantly faster clearance of 2-AP and higher affinity to the organs, especially the liver, compared with the 2-AP in solution, suggesting that it could selectively deliver 2-AP to the liver. Thus, the lipid emulsion with soybean oil and lecithin could be used as a potential dosage form with the liver-targeting property and enhanced stability of sparingly water-soluble 2-AP.     

大豆油脂肪酸甲酯化条件的研究

氢氧化钾-甲醇甲酯化是用气相色谱法测定植物油脂肪酸组成的常用衍生方法。本文采用单因素试验及正交试验,以大豆油中亚油酸为主要考核目标,同时,观察其他主要脂肪酸含量变化,研究氢氧化钾-甲醇法甲酯化的优化条件。     

An inexpensive route to prepare mesoporous hollow silica microspheres using W/O ethanol/edible soybean oil macroemulsion as the template

Mesoporous hollow silica microspheres were prepared by using W/O emulsion consisting of ethanol droplets as a template in edible soybean oil. Ethanol droplets containing ammonia solution were generated by employing ultrasonication in pure soybean oil. The droplets were colloidally stabilized by means of a cationic surfactant, cetyltrimethylammonium bromide (CTAB). Later on, another proportion of soybean oil dissolving tetraethyl orthosilicate (TEOS) was added to the W/O emulsion. The sol-gel reaction of TEOS was achieved only at the interface of the emulsion droplets, resulting in hollow silica microspheres. After washing the resultant with acetone, mesoporous hollow silica microspheres were simply obtained. Throughout this liquid template-based process, mesoporous hollow silica microspheres can be inexpensively synthesized without employing solid templates.     

Encapsulation Study of 6-Methylprednisolone in Lipid Microspheres

The search for new pharmaceutical forms that provide greater security and efficiency is one of the main research activities of pharmaceutical technology. This paper concerns a detailed study of the encapsulation of a glucoconicoid with anti-inflammatory action (6-methylprednisolone) in lipid microspheres, one of the systems used for the transport and delivery of lipid-soluble-type drugs. The method used, in common with previous experiments, was that of the solubilization of the constituents of the oil phase (refined soybean oil, soybean lecithin, cholesterol, and the active agent) and, separately, of the aqueous phase of the emulsion (Tween 80, glycerol, and distilled water). The two phases were then mixed by mechanical shaking, and the micelles were homogenized and filtered through membranes of 1.20-μm pore diameter. To determine the percentage encapsulated of the active agent, the first step was the separation of the encapsulated fraction from the free fraction in the medium by molecular exclusion chromatography or filtration in gel. A dextrose (Sephadex G-50 fine) gel was used for the absorbent or stationary phase, and distilled water was used for the eland, or mobile phase. me determination of the free glucocorticoid in the hydroethanol solution by ultraviolet spectrophotometry at 243 nm permits us to calculate the percentage taken by the microspheres. The formula composed of soybean oil and lecithin in the ratio 1:1.1 (w/w), cholesterol (0.50 g/100 ml), Tween 80 (0.25 g/100 ml), and glycerol (0.63 g/100 ml) produced the greatest quantity of encapsulated active agent: 84.91 ± 4.45%.     

等规聚丙烯/豆油溶液体系的结晶过程研究

采用DSC法对等规聚丙烯(iPP)／豆油溶液的非等温结晶过程进行了研究．研究了聚丙烯浓度和降温速率对结晶温度的影响，结晶温度随降温速率升高而下降，随iPP含量增加略有上升，用自制热台在自然降温条件下对聚丙烯／豆油溶液的浊点进行了测定，结合DSC法的测定结果，绘制了聚丙烯／豆油体系的非平衡相图．另外研究了成核剂对结晶温度的影响，研究发现加入成核剂后iPP／豆油体系的结晶温度提高了15℃以上．     

肉桂油气相色谱与气质联用分析

目的:建立肉桂油中桂皮醛的含量测定方法和鉴定挥发性化学成分。方法:气相色潜法,3mm×4m不锈钢柱,10％PEG-20M为固定液,Chromosorb WAW 60-80目担体,FID检测器,柱温190℃;气质联用,以HP-5毛细管柱,柱温起始120℃保持5min后以5C/min升温至150(保持7min,检测质荷比范围10-425。结果:桂皮醛在2-10mg/mL范围内具良好线性关系,平均回收率为99.98％,RSD为1.3％,气质联用鉴定了39种化合物。结论:方法简便,快速,准确,可有效排除其它成分的干扰。     

Characterization of vegetable oils by electrospray ionization mass spectrometry fingerprinting: classification, quality, adulteration, and aging

An improved approach for the direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis of vegetable oils is described. The more polar components of the oils, including the fatty acids, are simply extracted with methanol/water (1:1) solution and analyzed by direct infusion ESI-MS in both the negative and positive ion modes. This fingerprinting analysis was applied to genuine samples of olive, soybean, corn, canola, sunflower, and cottonseed oil, to admixtures of these oils, and samples of aged soybean oil. ESI-MS fingerprints in the positive ion mode of the extracts divide the oils into well-defined groups, as confirmed by principal component analysis, whereas ESI-MS fingerprints in the negative ion mode clearly differentiate olive oil from the five other refined oils. The method is also shown to detect aging and adulteration of vegetable oils.