RP-HPLC测定南、北五味子中三种木脂素类成分的含量

采用反相高效液相色谱(RP-HPLC)法检测五味子中三种木脂素类成分的含量。色谱柱为Agilent C18色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇-水(75∶25),流速1.0 m L/min,检测波长250 nm,柱温30℃,进样量10μL。结果表明,3种成分的进样量分别在4~800、4~400、4~400μg/m L范围与各自峰面积积分值呈良好的线性关系(r分别为0.999 3,0.999 8,0.999 9),平均回收率分别为98.44%,98.86%和97.84%,RSD分别为1.24%,1.87%和1.18%(n均为5)。北五味子中五味子醇甲、五味子甲素和五味子乙素含量分别为7.196,1.344,3.476 mg/g,南五味子中不含五味子醇甲,五味子甲素、五味子乙素的含量依次为59.065,3.213 mg/g。该方法快速、准确、重现性好,可用于南、北五味子中木脂素类成分的分析,评价不同来源五味子的质量。     

五味子药材中醇甲和酯甲的测定

五味子以100%甲醇溶解,用超声波清洗器提取20 min,建立一种同时对五味子药材中五味子醇甲和酯甲定性和含量测定的HPLC-MS方法。色谱条件:色谱柱ZORBAXEclipse XDB-C18(150 mm×4.6 mm i.d.,5μm),流动相甲醇-水(体积比65∶35),流速0.8 mL/min,检测波长220 nm,柱温20℃,进样量20μL。质谱条件:电喷雾离子源(ESI+源),扫描范围(m/z):300~600,干燥气温度350℃,干燥气流速8.0 mL/min,雾化气压力275.8 kPa。结果表明,五味子醇甲和酯甲分别在1.3~83.2μg和1.04~66.56μg浓度范围内具有良好的线性关系,相关系数r分别为0.998和0.997,平均加标回收率分别为100.7%和99.7%,RSD均小于2%。本方法灵敏度高、操作简便、结果准确,可用于五味子中五味子醇甲和酯甲定性及定量的测定。     

HPLC法测定舒肝益脾颗粒中五味子甲素的含量

采用高效液相色谱法测定舒肝益脾颗粒中五味子甲素的含量,Agilent—EclipseXDB—C18色谱柱（4．6mm×250mm,5μm）,以乙腈-水进行梯度洗脱,流速1．00mL／min,柱温30℃,检测波长254nm,进样量10μL。结果表明,五味子甲素浓度在0．632—25．28μg/mL范围内与峰面积呈良好的线性关系,r=0．9995;加样平均回收率为99．08％,RSD=0．84％。本方法操作简便,分离效果较好,准确可靠,适用于舒肝益脾颗粒中五味子甲素的含量测定。     

利用HPLC法建立五味子醇甲的检测方法及其方法学考察

[目的]通过高效液相色谱法(HPLC法)建立五味子醇甲的检测方法及其方法学考察。[方法]利用高效液相色谱仪对五味子醇甲进行测定,[结论]本方法操作简单,准确可靠,结果稳定,重复性好,可用来测定五味子醇甲的含量。INERTSLLODS_SP C18(150 mm×4.6 mm,5μm);流动相为甲醇-水(77︰23);流速为1 mL/min;检测波长:254 nm;柱温:30℃;进样量20μL,回归方程为y=38235x+2579.1,R~2=0.9997。[结果]五味子醇甲在6.72~15.12μg/mL范围内,峰面积与进样量呈良好的线性关系。     

HPLC法测定北五味子果实中五味子甲素含量

采用高效液相色谱法,测定了五味子果实中五味子甲素的含量,检测波长为254nm,标准曲线线性关系R2为0．9992,相对标准偏差为0．59％,平均加样回收率为99．16％。结果表明,此方法准确度较高,为五味子生药及成品药中五味子甲素含量测定提供了一种切实可行的方法。     

五味子中木质素类活性成分的高效液相色谱分析

本文建立了五味子药材中五味子醇甲、五味子甲素和五味子乙素含量的测定方法。方法：采用反相高效液相色谱法,使用Kromasil C18柱（250mm×4．6mm,5μm）,以乙腈一水梯度系统为流动相,流速1．0mL·min-1,检测波长218nm。结果：五味子醇甲、五味子甲素、五味子乙素线性范围分别为19．92～398．4、6．24～124．8、12．5～250μg·mL-1,平均回收率分别为99．5％、98．6％、98．5％。结论：本法可用于五味子药材的质量控制。     

五味子药材HPLC指纹图谱的研究

采用HPLC/UV测定五味子药材甲醇提取液的指纹图谱,并对不同产地的五味子的指纹图谱进行比较.色谱条件:ODS色谱柱,甲醇-水线性梯度洗脱,流速1.30 mL·min-1,检测波长220 nm,柱温30℃.结果发现指纹图谱中有22个色谱峰为共有峰,根据其相对保留时间和紫外光谱,确定五味子甲素、五味子乙素、五味子丙素、五味子醇甲、五味子醇乙、五味子酯甲6个成分,并计算了13个样品间相似度.研究证实五味子指纹图谱可用于全面控制五味子药材的质量.     

HPLC法测定复元胶囊中五味子醇甲的含量

建立复元胶囊中五味子醇甲的含量测定方法。采用高效液相色谱(HPLC)法对复元胶囊中五味子主要成分五味子醇甲(C₂₄H₃₂O₇)进行含量测定;流动相为甲醇-水(65∶35),检测波长为250 nm。五味子醇甲(C₂₄H₃₂O₇)在4.096～40.96μg/mL范围内溶液浓度与峰面积存在良好的线性关系,定量限为0.399μg/mL,检测限为0.120μg/mL,平均回收率为94.4%,RSD为0.6%(n=6);精密度试验、重复性试验、稳定性试验均良好。该方法灵敏度高、准确可靠,可以有效地控制复元胶囊的质量。     

紫外辐射对五味子叶片中五味子甲素含量的影响

采用UVA、 UVB、 UVC三波段紫外光为五味子新鲜叶片进行辐射,研究波长、辐射时间及样品处理方式对五味子叶片中五味子甲素含量的影响。结果表明紫外辐射提高了五味子甲素的含量,但不同辐射波段对甲素含量增加幅度大小不一。其中以UVB为最佳紫外辐射,五味子甲素含量有明显增加,以6天为宜,含量最高提高了88.2%。     

RP-HPLC测定雷公藤药材中雷公藤甲素

采用反相高效液相色谱法-紫外检测器(RP-HPLC-UV)测定雷公藤药材中雷公藤甲素的含量,色谱柱为Kromasil C18柱(150 mm×4.6 mm,5μm),甲醇∶水溶液(45∶55)为流动相进行等度洗脱,流速1.0 mg/min,进样量20μL,紫外检测波长λ=218 nm。结果表明,每个样本分析时间约10 min,雷公藤甲素保留时间约6.103 min,雷公藤甲素与其他成分分离效果良好,标准曲线y=0.206 7x+2.123 9,r=0.993 3(n=5),线性范围0.01~0.1 mg/m L(r=0.993 3),回收率为96.00%~99.03%,RSD≤2%。本方法专属性强,准确可靠,可以用于雷公藤药材中雷公藤甲素的含量测定。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。