黄酒中挥发性和半挥发性成分检测固相微萃取条件的优化

采用固相微萃取-气相色谱联用质谱法分析黄酒中的挥发性和半挥发性成分,对萃取时间、萃取温度、预热时间、酒样添加量、盐添加量、解析时间等条件参数进行了优化,最终确定最佳条件为采用50/30 μm DVB/CAR/PDMS萃取头,在20 mL顶空瓶中,加入6 mL黄酒样和2.0 g NaCl,萃取温度60℃,预热时间15 min,萃取时间30 min,解析温度250℃,解析时间6 min。本方法简单快速,干扰少,灵敏度高。     

糖蜜草挥发性成分HS-SPME-GC-MS分析

本文首次采用顶空固相微萃取技术(HS-SPME)提取该植物挥发性成分,然后通过气质联用技术(GC-MS)结合保留指数以及标样对照对化学成分进行了定性,并通过峰面积归一化法计算出各组分的相对百分含量。试验确定了PDMS/DVB固相微萃取对糖蜜草挥发物的萃取效果最好,并从中鉴定出33种化合物占总挥发性成分的90.94%,主要为烷烃和萜烯类化合物。该研究为开发糖蜜草作为水稻螟虫的驱避植物进行害虫安全有效防治提供理论依据,并为驱避性挥发物的田间应用奠定基础。     

采用多次顶空固相微萃取分析拟南芥绿叶挥发性物质

顶空固相微萃取作为一种新的挥发性和半挥发性物质分析技术,被广泛应用于植物样品的定性分析。由于进行顶空分析时,挥发性组分间的基质效应以及较为复杂的扩散和吸附过程,定量分析一直是SPME分析应用的难题。目标分析物的量看作是达到吸附平衡后单一萃取的物质量的总和,则无需考虑分析样品在顶空、萃取涂层间的分配,同时可以消除基质效应。在利用标准物质进行校正后只需要一次顶空萃取,即可求出分析物质的总量。首先利用DVB/CAR/PDMS定性得到拟南芥挥发性物质的组成,然后采用CAR/PDMS涂层定量,分析了拟南芥的3种绿叶挥发性物质,优化后萃取条件为40℃萃取20min,相对标准偏差小于12%,在3株植物样品中这些挥发性物质的量为78.6~158.4ng.g-1。     

固相微萃取气质联用分析百里香花和叶挥发性成分

利用顶空固相微萃取技术(SPME)采集百里香Thymus mongolicus花和叶的挥发性成分,采用GC/MS技术分析鉴定,并用峰面积进行归一化定量。结果表明,从百里香花和叶总离子流图中分别鉴定出24、14种化合物,分别占总峰面积的99.573%和97.187%。百里香花和叶主要成分包括酚类和萜烯类,其中百里香酚在百里香花和叶中分别占35.38%和49.13%。     

HS-SPME-GC-MS分析枸骨叶挥发性成分

以顶空固相微萃取技术(HS-SPME)提取枸骨叶的挥发性成分,采用气质联用技术(GC-MS)结合保留指数法,用峰面积归一法测定相对百分含量。从枸骨叶中鉴定出32个化合物,占总峰面积的91.30%。化学成分主要为植酮(19.64%)、二氢猕猴桃内酯(5.38%)、壬醛(5.10%)和六氢假紫罗酮(3.94%)。     

顶空气相色谱法检测破伤风抗毒素中的甲苯残留量

目的建立检测破伤风抗毒素中甲苯残留量的顶空气相色谱法。方法参照《中国药典》三部(2015版)"残留溶剂测定法",采用Agilent DB-1301毛细管色谱柱(15.0 m×530μm×1.00μm)及氢火焰离子化检测器;顶空进样器各参数分别为:平衡温度70℃,平衡时间30 min,定量环温度80℃,传输线温度90℃,进样量1 m L;气相色谱仪各参数为:进样室温度100℃,柱温箱温度60℃,检测器温度220℃,载气氮气流速5 m L/min,采集时间5min;并对该方法的系统适用性、专属性、线性范围、准确度和精密度、检测限和定量限进行验证及初步应用。结果甲苯保留时间2.429 min,峰面积的RSD为1.9%,以甲苯色谱峰计算得到的理论塔板数N=12 900,甲苯色谱峰与其相邻色谱峰的分离度R=6.03。方法的专属性强,制品中的其他物质不干扰甲苯的出峰;标准曲线的范围为1.0×10-4%~2.0×10-3%,相关系数r大于0.99;加标试验的回收率分别为96.0%~102.9%、100.7%~111.0%,重复性和日间精密度RSD均小于5%。检出限为2.6×10-6%,定量限为1.0×10-5%。测定10批破伤风抗毒素成品和10批破伤风抗毒素原液,其甲苯残留量均低于检出限,远低于规定的限度0.089%。结论该方法简便、快速、准确度、灵敏度高、精密度好,适用于破伤风抗毒素类制品中甲苯残留量的检测。     

顶空进样与水蒸气蒸馏GC-MS法分析杠板归中挥发性成分

分别采用顶空进样法和水蒸气蒸馏法提取杠板归的挥发性成分,对得到的样品分别进行气相色谱-质谱(GC-MS)分析。对顶空进样得到的挥发性物质和水蒸气蒸馏法得到的挥发油物质进行气质联用色谱分析,在相同条件下用同种检索谱库检索,顶空进样直接得到的挥发性物质进行气质联用色谱分析,得到了42种化合物,含量都大于0.10%,且差别较小;水蒸气蒸馏得到了61种化合物,但含量大于0.10%的只有33种,且差别较大。说明不同的收集方法分别提供了不同沸点和不同状态下杠板归药材中挥发性成分的结构和百分含量;对比综合这两种不同的方法得到的挥发性成分,可得到更全面、更详细的杠板归中挥发性成分的GC-MS实验情况。     

HS-SPME-GC-MS分析槟榔果皮和种子的挥发性成分

采用顶空固相微萃取和气质联用技术(HS-SPME-GC-MS),首次分析槟榔果皮和种子的挥发性成分。从槟榔发黄果皮和青果皮中分别鉴定出29和21种成分,分别占总峰面积的89.18%和71.96%,从发黄果实种子和青果实种子中分别鉴定出20和15种成分,分别占总峰面积的87.47%和70.24%,发黄果皮和青果皮有8个共有成分,发黄果实种子和青果实种子有13个共有成分,四者有5个共有成分。槟榔果皮和种子的挥发性成分具有差别。     

红花檵木花和叶挥发性成分

采用顶空固相微萃取和气质联用技术(HS-SPME-GC-MS),结合保留指数法并用峰面积归一化法,测定红花檵木花和叶挥发性成分的相对百分含量,从花和叶中分别鉴定出26和29个化合物,其占总面积分别为92.14%和73.97%。红花檵木花与叶的挥发性成分具有差别,挥发性成分相对含量花比叶明显高。     

海州常山挥发性成分HS-SPME-GC-MS分析

本文首次采用顶空固相微萃取和气质联用技术(HS-SPME-GC-MS),分析了海州常山花的挥发性成分.从海州常山花中共鉴定出了27种化合物,占挥发油成分总峰面积的94.10％,主要有烷烃、醛、醇和酸类.其中含量较高的成分有2,6,10,14-四甲基十六烷(17.25％)、棕榈醛(10.57％)、1-辛烯-3-醇(6.7...     

Studies on the Aroma Constituents of Fuiien Ti Kuan Yin Tea,Se Chung Tea,Wu-I Shui Hsien Tea and Wu-I Chi Chung Tea in China

This paper reports, for the first time, the aroma constituents of the famous Fujian Oolong tea—Ti kuan Yin Tea, Se Chung Tea, Wu-I Shut Hsien Tea and Wu-I Chi Chung Tea. 70 aroma concentrates of tea samples were identified by the use of (IC-MS, SCOT capillary coumn GC standard sample addition method and IR. Among which benzyl alcohol, translinalooloxide (furanoid), cis-linalooloxide (fuconoid), 3,7-dimeihy-l,5, 7-octatrien-3-ol, β-phenylethanol, translinalooloxide (pyranoid), geraniol, indole, eisjasmone, pasmine laetone, nerolidol and mthyl jasmonate are the typical character the aroma constituents. Consequently the aroma is varied by different varieties of the tea, different regions of their growth and different processing.     

响应面法优化混合酶-超声波联合提取栀子黄色素工艺研究

以栀子为原料提取栀子黄色素,将混合酶-超声波技术相结合,对栀子黄色素进行了提取的研究。为了获得提取栀子黄色素最佳工艺条件,采用响应面法组合设计试验方法,建立了酶的用量、提取温度、提取时间之间关系。结果表明,最佳工艺条件为酶的用量4.33%,提取温度61.84℃,提取时间65.06 min,在此最佳提取条件下,栀子黄色素的吸光度为0.914。     

响应面法优化超声提取绿茶茶多酚工艺

利用响应面法对超声提取绿茶荼多酚的工艺条件进行优化,在单因素试验的基础上,根据中心组合设计原理采用三因素三水平的响应面分析法,依据回归分析确定最优提取工艺条件。结果表明,其最佳工艺条件为：液料比为40．2mL／g,超声功率为476W,提取时间为15．1min,采用该工艺条件,茶多酚的提取得率达到10．312％,通过响应面法得到一个能较好预测试验结果的模型方程。     

Arsenic removal from groundwater by pretreated waste tea fungal biomass

Arsenic contamination in ground water poses a serious threat on human health. The tea fungus, a waste produced during black tea fermentation has been examined for its capacity to sequester the metal ions from ground water samples. Autoclaved tea fungal mat and autoclaving followed by FeCl3 pretreated tea fungal mat were exploited for removal of As(III), As(V) and Fe(II) from ground water sample collected from Kolkata, West Bengal, India. The biosorption rate tends to increase with the increase in contact time and adsorbent dosage. FeCl3 pretreated and autoclaved fungal mats removed 100% of As(III) and Fe(II) after 30 min contact time and 77% of As(V) after 90 min contact time. The optimum adsorbent dosage was 1.0 g/50 mL of water sample. The results revealed that the FeCl3 pretreated fungal mat could be used as an effective biosorbent for As(III) and As(V); autoclaved fungal mat for Fe(II) removal from ground water sample.     

桦褐孔菌三萜化合物提取工艺的优选

为了提高桦褐孔菌三萜化合物的产量,对其三萜化合物的提取工艺进行了初步优选。试验以桦褐孔菌发酵菌丝体为材料,齐墩果酸为标准品,用香草醛比色法测桦褐孔菌三萜化合物含量。通过单因素实验考察了不同提取剂、提取剂用量、提取温度、提取时间对桦褐孔菌三萜化合物提取的影响。结果表明,提取的最佳工艺为：以异丙醇为提取溶剂,用量为7倍,最佳提取温度为80℃,提取时间2h,在此条件下三萜化合物占菌丝体干质量的9．03％。该工艺的三萜桦褐物的提取率高,可用于桦褐孔菌中三萜化合物的提取。     

Improved preparation of vitexin from hot water extract of Basella alba,the commercially available vegetable Malabar spinach (“Tsurumurasaki” in Japanese) and the application to semisynthesis of chafuroside B

ABSTRACT

Hot water extraction of D-arabinofuranosylvitexin from the raw leaves of commercially available Basella alba “Tsurumurasaki” and subsequent acidic hydrolysis was improved to be a procedure using a high-pressure steam sterilizer to afford vitexin. The amount was estimated to be 14.1 mg from 1 g of dry weight of the raw leaves, whose recovery was calculated to be 95% based on the estimated content of D-arabinofuranosylvitexin in B. alba raw leaves. The product was dehydratively cyclized between hydroxy groups on the carbohydrate and flavone skeletons under modified Mitsunobu reaction conditions in N,N-dimethylformamide to give chafuroside B, which is known to be a bioactive Oolong tea polyphenol. Through these transformations, 10.2 mg of chafuroside B could be semisynthesized from 1 g of dry weight of the raw leaves, and the efficiency was improved compared to that from the extraction from Oolong tea (3.4 μg from 1 g of dry weight).     

Recovery of catechin compounds from Korean tea by solvent extraction

Catechin compounds from Korean green tea as potential sources of anticancer and antioxidant components were target materials in this work. The methodologies of solvent extraction and partition were utilized to recover catechin compounds from green tea. The optimum experimental condition was obtained by optimizing operating factors, such as, the extraction solvent, extraction time and operating temperature. After extracting the green tea with water at 80 degrees C for 40 min, the extract was partitioned with water/chloroform, which was best suited to remove caffeine impurity from the extract. Further, the resulting extract was partitioned water/ethyl acetate to deeply purify the catechin compounds of EGC, EC, EGCG and ECG. The experimental result in this work could be extended to preparative HPLC to obtain EGCG on commercial scale.     

响应面法优化超临界CO2萃取茉莉花蕾精油及抗氧化活性的研究

为研究超临界CO2萃取茉莉花蕾获得精油的最佳工艺及抗氧化活性,实现资源的综合利用。实验考察了夹带剂用量、原料颗粒大小、萃取压力、萃取温度和动态萃取时间对茉莉精油产率的影响,进一步以响应面实验设计优化挥发油的提取工艺参数,以GC-MS分析挥发油组成及相对含量,并测定精油清除DPPH自由基及还原铁离子能力。结果表明,最佳工艺参数为:夹带剂乙醇用量为0.2mL/g,花粉颗粒为40目,萃取压力20MPa,萃取温度46℃,动态萃取时间1.6h。在此条件下茉莉精油的产率为13.67%,远高于同时蒸馏萃取法(2.87%)和超声辅助提取(2.45%)。超临界萃取精油的主要香气成分与茉莉鲜花基本一致,并且具有较好的清除自由基和还原铁离子能力。实验证明超临界萃取技术提取茉莉花蕾得到茉莉精油品质高,可为其资源综合利用提供参考。     

Headspace solid-phase microextraction and capillary gas chromatographic-mass spectrometric determination of rivastigmine in canine plasma samples

A simple, rapid and sensitive method for determination of rivastigmine in plasma samples was developed using headspace solid-phase microextraction (HS-SPME) and gas chromatography with mass spectrometry (GC-MS). The optimum conditions for the SPME procedure were: headspace extraction on a 65-microm polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber; 0.5 ml of plasma modified with 1.0 ml of sodium hydroxide-sodium carbonate solution (0.7 M:0.5M); extraction temperature of 100 degrees C, with stirring at 2000 rpm for 30 min. The calibration curve showed linearity in the range from 0.2 to 80 ng/ml with regression coefficient corresponding to 0.9965 and coefficient of the variation of the points of the calibration curve lower than 10%. The quantification limit for rivastigmine in plasma was 0.2 ng/ml. The method was applied to determination of rivastigmine in canine plasma samples from animals after a single oral administration.     

设施番茄果实生长与环境因子的关系

在设施环境下,研究环境因子与番茄果实生长的关系,以期为设施番茄精准管理提供参考。以1h为步长,记录设施内温度、光照强度及空气湿度,每7d进行1次果径测定,将采集的环境数据细分为7个变量,分析7个变量与果实日增量随时间的变化,采用DPS软件进行逐步回归,建立显著环境因子与果实日增量的回归模型。春茬两个棚环境因子随时间动态变化规律较一致,秋茬日光温室与其有所不同。番茄品种'粉冠’和'金棚’果实日增量呈现先升高后降低的趋势,品种'珍琪’果实日增量变化波动较大。3个设施内影响果实日增量的显著环境因子有所不同,7个环境变量之间相互影响、相互制约。剔除不显著的环境变量后,建立了3个番茄品种果实日增量与显著环境变量的回归模型,确定了7个环境因子对果实生长的影响及果实生长适宜的环境变量范围。