RP-HPLC法测定朝鲜蓟中绿原酸的含量

建立了朝鲜蓟中绿原酸测定的高效液相色谱法。采用DiamandC_(18)色谱柱(200×4.6mm 5μn)(迪马公司色谱专家),以乙腈-水-甲酸(体积比23∶230∶1.2)淋洗,用紫外检测器于328nm处测定,各组分的色谱峰达到基线分离。绿原酸在7.2～360 ng/mL 范围内线性关系良好,线性方程为Y=6.379×10~(-4)-0.597,线性相关系数r=0.9999;平均回收率为102.37%;RSD=1.422%(n=7)。并对朝鲜蓟不同部位的绿原酸含量进行了测定,结果满意。     

高效液相色谱法测定向日葵花盘中绿原酸含量

建立了向日葵花盘中药用成分绿原酸的高效液相色谱(HPLC)定量分析方法。色谱柱:Agilent XDB C18(4.6 mm×50 mm,1.8μm);流动相:乙腈:0.1%磷酸(11∶89);流速:0.5 mL/min;检测波长:328 nm。通过测定,向日葵花盘中绿原酸含量为0.227%。方法精密度RSD为0.13%,重复性良好,平均回收率为102.69%,绿原酸浓度在0.67～67μg/mL呈良好线性关系,r=0.99998。该方法稳定、可靠,可作为该药材的质量控制方法。     

HPLC同时测定蒲公英中咖啡酸和绿原酸的含量研究

目的:建立蒲公英中咖啡酸和绿原酸含量的HPLC测定方法。方法:采用Agilent ZorbaxSB-C1(85μm,150 mm×4.6 mm),流动相为甲醇-磷酸盐缓冲液(23:77,V/V),pH=4.0,流速0.8 mL/min,检测波长为323 nm,柱温为室温。结果:在0.00780～0.04160 mg/mL范围内咖啡酸含量与其峰面积呈良好的线性关系,平均加样回收率为98.92%;在0.00848～0.04784 mg/mL范围内绿原酸含量与其峰面积呈良好的线性关系,平均加样回收率为99.13%。结论:采用HPLC测定蒲公英中咖啡酸和绿原酸的含量简便、准确、选择性好,可用于蒲公英中咖啡酸和绿原酸的含量测定。     

RP-HPLC法测定厄贝沙坦的含量及有关物质

目的:建立RP-HPLC法测定厄贝沙坦的含量及有关物质。方法:采用ShimadzuVP-ODS(150mm×4.6mm,5μm)色谱柱,乙腈-0.02mol/L磷酸二氢钾溶液(用磷酸调节pH=2.6()40:60)为流动相,检测波长245nm,流速1.0mL/min。结果:厄贝沙坦与各杂质及降解产物分离良好,在4-240μg/mL范围内线性关系良好(r=0.9999),平均回收率99.73%,RSD为0.77%,最低检出限0.6ng。结论:该方法简便、快速、准确,可用于厄贝沙坦含量及有关物质的测定。     

反相高效液相色谱法同时测定生物转化液中苯乙酮和肉桂酸

建立RP-HPLC法测定生物转化液中苯乙酮和肉桂酸的含量。色谱条件:采用Kromasil-100AC18柱(250 mm×4.6 mm,5μm);以甲醇-水-冰醋酸(体积比为75∶25∶0.05)为流动相;流速为1.0 mL/min;检测波长为246 nm;柱温为室温。结果表明,苯乙酮在1.60~320.0μg/mL范围内呈良好线性关系(r=0.999 2);肉桂酸在2.00~400.0μg/mL范围内呈良好线性关系(r=0.999 6)。苯乙酮和肉桂酸的平均回收率分别为100.42%和101.75%,相对标准偏差(RSD)分别为1.3%和1.7%。     

HPLC法测定天山花楸叶提取物黄酮苷的含量

为了建立天山花楸叶中总黄酮苷含量的测定方法,对样品酸水解处理再进行HPLC分析,色谱柱为Waters-C18(150 mm×4.6 mm,5μm),柱温25℃,使用可变波长检测器;流动相为甲醇-乙腈-0.4%磷酸水溶液,梯度洗脱程序为0 min(12∶20∶68)-10 min(52∶0∶48)-18 min(72∶0∶28);流速1.0 mL/min,检测波长为360 nm。结果表明:槲皮素浓度在5.98～47.84μg/mL之间与色谱峰面积呈良好的线性关系,回归方程A=66.96C-5.9964,r=0.9995。平均回收率94.86%,RSD=1.9%;山柰素浓度在4.04～28.28μg/mL之间与色谱峰面积呈良好的线性关系,回归方程A=50.114C-19.529,r=0.9999,平均回收率93.89%,RSD=2.7%;其黄酮苷百分含量为(12.62±0.40)%。该方法干扰少,灵敏,简便,重现性好,可为天山花楸叶的药用开发利用提供质量控制方法。     

RP-HPLC测定盐酸氟西汀有关物质的方法学研究

建立了采用反相高效液相色谱(RP-HPLC)法测定抗抑郁药盐酸氟西汀有关物质的方法。使用Agilent Zorbax Eclipse Plus C8柱(4.6 mm×250 mm×5μm)或效能相当的色谱柱;以三乙胺缓冲溶液-甲醇-四氢呋喃溶液为流动相进行等度洗脱,流速为1.0 mL/min;检测波长为215 nm;柱温箱温度为25℃。在上述色谱条件下,盐酸氟西汀与各杂质分离效果良好(Rl.5),检测限为1.003 5 ng/mL,定量限为3.456 5 ng/mL,在1.721 6～6.886 4μg/mL范围内,质量浓度与峰面积成线性关系(R2=0.999 1),且辅料对主药的测定无干扰。该方法简单快速、准确稳定,且专属性良好,可用于盐酸氟西汀胶囊有关物质的测定。     

1型肺炎球菌荚膜多糖中十六烷基三甲基溴化铵含量反相高效液相色谱检测方法的建立及验证

目的建立检测1型肺炎球菌荚膜多糖(简称Pn1型多糖)中残留十六烷基三甲基溴化铵(cetyltrimethylammonium bromide,CTAB)含量的反相高效液相色谱(reversed-phasehigh performance liquid chromatography,RP-HPLC)方法,并进行验证。方法色谱条件:选用反相色谱柱Waters/XSelect CSH C18(4.6 mm×250 mm,5μm),流动相为含三氟乙酸(trifluoroacetic acid,TFA)的10%甲醇水溶液,梯度洗脱,流速为1.0 mL/min,柱温为20℃,检测波长为206 nm。优化流动相甲醇中TFA的比例(0.01%、0.05%和0.1%)。Pn1型多糖用100μg/mL脱氧胆酸钠(sodium deoxycholate,DOC)水溶液溶解,超滤离心后上样。验证方法的专属性、线性范围、灵敏度、准确性及重复性。应用该方法检测3批Pn1型多糖样品CTAB残留量。结果选择含0.01%TFA的10%甲醇水溶液作为流动相;加标样品除有CTAB对照品色谱峰外,还有2个杂质峰,且3个峰均达到基线分离,表明方法专属性良好;CTAB对照品在0.2～4.0μg/m L浓度范围内与峰面积线性良好,r~2 0.999;检出限及定量限分别为0.1和0.2μg/mL;0.2、0.4及0.6μg/mL浓度的加标样品回收率分别为101.18%、100.85%和101.72%,平行检测3次的RSD分别为1.69%、1.98%和0.76%。3批样品CTAB残留量均0.324μg/mL,符合内控要求。结论成功建立了检测Pn1型多糖中残留CTAB含量的RP-HPLC法,该方法具有良好的专属性、线性、准确性,灵敏度高,重复性好,可用于肺炎球菌荚膜多糖中的残留CTAB检测。     

RP-HPLC法测定阿莫西林、盐酸环丙沙星可溶性粉的含量

应用RP-HPLC法测定阿莫西林、盐酸环丙沙星可溶性粉的含量。Shim-packCLC-ODS柱(150mm×6mm,5μm),以V(15mmol/L三乙胺溶液,用磷酸调pH至3.0):V(乙腈)=850:150为流动相,流速为1.0mL/min;检测波长为229nm,柱温为40℃。在此色谱条件下两者能完全分离,阿莫西林、盐酸环丙沙星在20～100μg/mL的范围内浓度与峰面积呈良好的线性关系,相关系数均为r=0.9999。阿莫西林、盐酸环丙沙星的平均回收率分别为99.9%、99.8%;RSD分别为0.78%、0.88%。方法可用于阿莫西林、盐酸环丙沙星可溶性粉的质量控制。     

甘草中甘草酸的含量测定方法研究

以高效液相色谱法检测甘草中甘草酸的含量。方法:色谱柱为C18(150 mm×4.6 mm,5μm),流动相为乙腈-0.05%磷酸(38∶62),检测波长为252 nm,流速为1.0 mL·min~(-1),柱温为室温。结果:甘草酸在50～350μg/mL浓度范围内与峰面积呈良好的线性相关性(r2=0.99993);平均回收率为100.41%,RSD为0.57%(n=9),准确度良好。该方法简便、准确、可靠,适用于测定甘草及其制剂产品中的甘草酸含量。     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.