乳酸左氧氟沙星眼用凝胶的含量测定

建立一种乳酸左氧氟沙星眼用凝胶中左氧氟沙星含量的测定方法.以C18柱为分析柱,以醋酸铵高氯酸钠-乙腈(82∶18)溶液为流动相.检测波长为293 nm,柱温室温,外标法测定,线性范围为0.01～0.4 mg/mL,线性方程为A=5.541 ×107C～1.438×104,r=1.000,回收率为99.68%,RSD为0.72%.本法简单、快速、准确,可用于乳酸左氧氟沙星眼用凝胶的含量测定.     

高效液相色谱测定40%乙烯利中6-苄氨基嘌呤方法的研究

首次建立了高效液相色谱测定40%乙烯利中6-苄氨基嘌呤含量的方法.色谱柱为Symmetry C18(150 mm×3.9 mm×5 μm);流动相为甲醇-水(V/V=50:50);流速为0.8 mL/min;线性回归方程为y=9.35×106x-3.52×103,r=0.999 8,线性范围为32.9～411 μg;加标回收率平均值为98.2%,RSD为1.42%.     

高效液相法测定清热解毒注射液中黄芩苷含量

目的:测定清热解毒注射液中黄芩苷的含量.方法:采用高效液相色谱法,测定条件为:色谱柱为Agela ODS(5um,4.6×200mm),流动相:甲醇-0.2%磷酸溶液(47:53);检测波长:276nm;流速:1.0ml/min;柱温:30℃.结果:木犀草苷在50.03-500.3μg/ml浓度范围内线性关系良好,r=0.9994,平均回收率为99.5(RSD=0.31%, n=6).结论:该方法稳定、可靠、专属性强,可用于清热解毒注射液中黄芩苷的含量测定.     

3-甲基-4-硝基-5-氯吡唑的HPLC测定法

目的:采用高效液相色谱法测定3-甲基-4-硝基-5-氯吡唑含量.方法:用Waters symmetryC8(3.9mm×150mm,5μm)色谱柱,流动相为乙腈-0.1%磷酸溶液(50:50),流速1mL/min,柱温:25℃,检测波长274nm.结果:在160.48μg/mL～401.20μg/mL范围成线性(r=0.9998,n=5),平均回收率为98.93%,RSD=1.91%.     

HPLC法测定铁甲草中大黄素的含量

建立铁甲草中大黄素的含量测定方法。采用高效液相色谱法(HPLC)测定铁甲草中大黄素的含量,应用Waters XBridgePeptide BEH C18(4. 6 mm×250 mm,5μm)色谱柱,以甲醇-0. 1%甲酸(85∶15)为流动相,流速1. 0 m L/min,柱温35℃,进样量为10μL,检测波长254 nm,测定大黄素的含量。大黄素浓度在5～50μg/m L范围内呈良好线性关系(Y=38315X-16555,R2=0. 9994),平均回收率为98. 94%,RSD为1. 98%(n=6)。本文方法准确灵敏、稳定可靠,可用于铁甲草中大黄素的含量测定。     

UPLC法同时测定蒲黄中两种黄酮类成分

采用超高效液相色谱法测定蒲黄水提液中香蒲新苷和异鼠李素-3-O-新橙皮糖苷的含量。采用UPLC,色谱柱:ACQUITY UPLC~? HSS T3(1. 8μm,2. 1 mm×100 mm),波长:254 nm、柱温:30℃、进样量:1. 4μL、以0. 3 m L/min乙腈-0. 1%甲酸溶液梯度洗脱。香蒲新苷的线性范围为0. 09369～0. 468μg,r=0. 9996(n=6),回收率为104. 76%,RSD=2. 16%(n=6);异鼠李素-3-O-新橙皮糖苷线性范围为0. 1441～0. 72072μg,r=0. 9996(n=6);回收率为103. 31%,RSD=2. 37%(n=6)。表明该方法操作简便,重复性好,结果准确,可用于蒲黄中两种黄酮类成分的含量测定。     

高效液相色谱法测定磺胺氯吡嗪钠含量

采用高效液相色谱法测定磺胺氯吡嗪钠含量,采用C18色谱柱(150mm×4.6mm,5μm),以甲醇为流动相,柱温为25℃,流速1.0mL/min,检测波长280nm。方法的线性范围100-400μg/mL,线性方程A=2.455×104C 28111,r=0.9999,平均回收率100.1%,RSD=0.74%。     

液相色谱法测定氮氧化物吸收液中尿素的含量

建立了液相色谱法测定氮氧化物吸收液中尿素含量的方法。色谱柱为NH2柱(250mm×4.6mm×5μm),采用乙腈(95∶5)流动相实现尿素与杂质峰的完全分离。尿素的浓度在0.0040-0.3000g/L范围内与色谱峰面积呈良好的线性。加标回收率为99.4-103.4%,测定结果的相对标准偏差为0.50%(n=10)。     

HPLC测定诃子全果、果肉及果核中没食子酸的含量

用高效液相色谱法测定诃子全果、果肉、果核中没食子酸的含量。检测方法为:采用Agilent C18柱(250 mm×4.6 mm,5μm),流动相为甲醇-0.1%磷酸(2.5∶97.5),柱温30℃,流速1.0 mL/min,检测波长273 nm。结果表明,没食子酸在0.117 6~1.294μg线性关系良好(r=0.9998);平均回收率为99.2%,RSD=1.3%(n=6)。没食子酸在诃子果肉中含量最高,果核中含量最低。结论:该方法操作简单、准确度高,可用于诃子中没食子酸的含量测定。     

反相高效液相色谱法测定N-（3-叔丁基-1H-吡唑-5-基）-N’-羟基-4-硝基苯甲脒含量

目的:采用反相高效液相色谱法建立质量控制的方法.方法:色谱柱为Inerstil ODS-3(250×4.6 mm,5 μm),流动相为乙腈-水-乙酸-三乙胺(50∶50∶0.2∶0.2),流速为1 mL*min-1,柱温为室温,检测波长为254 nm.结果:空白、中间体及杂质对样品测定不产生干扰;102E的浓度在0.2156～1.394 mg*mL-1范围内与峰面积呈良好线性关系(r=0.999 8,n=5);重复性良好(RSD=0.52%,n=6);检测限为32.5 μg*mL-1;平均回收率为99.61%(n=9).结论:该方法可以用于102E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。