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%。     

紫外分光光度法测定延胡索酸泰妙菌素预混剂的含量

实验建立了紫外分光光度法测定延胡索酸泰妙菌素预混剂的含量。实验结果表明,延胡索酸泰妙菌素的最大吸收波长为202nm,在此波长处,延胡索酸泰妙菌素在2.5~15.0μg/mL浓度范围内,其吸光度与浓度呈现良好的线性关系:A=0.0271c+0.0521,r2=0.9999(n=6)。该方法操作简单、测定快速,结果准确,可用于延胡索酸泰妙菌素预混剂的含量测定。     

CIPAC要求下炔草酸原药含量的测定

根据协同国际农药分析会(CIPAC)要求建立了一种用于测定炔草酸含量的快速分析方法。色谱分析条件如下:VP-ODS反相液相色谱柱(250mm×4.6mm),流动相:水和乙腈为40/60(v/v),流速1.0mL/min,检测器波长305nm,柱温30℃。结果显示:在15分钟内,炔草酸能够有效的分离,显示很好的重复性,在波长305nm下可以有效的避免其他杂质的干扰,同时紫外吸收值也能够达到最大,在注入量为1586-2398μg/mL,线性回归系数大于0.999,平均回收率在98.7.3%~～99.8%(n=5),检测限和定量限分别为0.2mg/L和0.7mg/L。以上方法和数据能够满足CIPAC对单个实验室方法验证的要求。     

草酸二甲酯和草酸的反相高效液相色谱分析

建立了反相高效液相色谱定量分析草酸二甲酯生产过程中的草酸二甲酯及草酸含量的方法。采用带有紫外检测器的Shimadzu LC-20A型高效液相色谱仪,C18色谱柱(4.6 mm×150 mm,5 μm),流动相是体积比为60:40的乙腈-磷酸水溶液(pH=2.7),流速为0.7 mL/min,柱温25 ℃,254 nm波长下紫外检测。探讨了pH值及其它条件对色谱分离的影响。该方法测得的草酸及草酸二甲酯线性回归曲线的相关系数分别为0.9996和0.9998,相对标准偏差为0.8%~1.0%,满足定量分析要求。     

反相高效液相色谱法测定1-(4-硝基苯)-3-(5-氯-2-吡啶)三氮烯

采用Zorbax Eclipse XDB-C8(4.6mm内径×150mm,5μm)色谱柱,乙腈流动相,流速0.70mL/min,检测波长407nm,建立了测定标题化合物的反相高效液相色谱法。该方法的线性范围是0.5~12.0μg/mL,回归方程为A=82.06c+10.16(r=0.9996),相对标准偏差3.218%(c=6.0μg/mL,n=5),检出限为0.05427μg/mL,平均回收率在96.81%~105.1%之间。     

高效液相色谱法测定化妆品中熊果酸的含量

采用甲醇超声提取,液相色谱分离的方法测定化妆品中熊果酸的含量。色谱条件为:Agilent HC-C18(250 mm×4.6 mm,5μm)色谱柱,流动相V(甲醇)∶V(水)∶V(冰乙酸)=87∶13∶0.03,流速1.0 mL/min,紫外检测波长215 nm。结果表明,在此条件下熊果酸在0.2μg/mL~103μg/mL与相应的峰面积具有良好的线性关系(r>0.999 7),线性回归方程为y=25.367 5x 0.546 9,回收率在96.4%~101.3%,方法精密度RSD<3.6%。     

高效液相色谱法定量测定淋洗类化妆品中的西曲溴铵

建立了化妆品中西曲溴铵的高效液相色谱(HPLC)分离检测方法。采用ZORBAX SB C18反相色谱柱(150 mm×4.6 mm,5μm),流动相为甲醇-0.1 M NaClO4溶液(pH 3.0)(70/30,体积比),采用等度洗脱方式,检测波长为208 nm,流速0.7 mL/min,以保留时间定性,外标法定量。结果表明,在此条件下西曲溴铵在1.25～200μg/mL范围内线性良好,检出限为0.35μg/mL,不同类型淋洗类化妆品中西曲溴铵的平均回收率在82.0%～118.7%范围内。方法操作简便,分离速度快,检出限低,适用于化妆品中西曲溴铵的测定。     

50%甲基嘧啶磷乳油的高效液相色谱分析

采用Hypersil C18(150mm×4.6mm,5μm)色谱柱,以甲醇–水(体积比3∶1)为流动相,流速1.0mL/min,检测波长254nm,测定50%甲基嘧啶磷乳油中的甲基嘧啶磷含量,变异系数为0.34%,平均回收率为99.6%。     

雷贝拉唑钠肠溶胶囊(微丸型)的HPLC分析

建立HPLC法测定雷贝拉唑钠肠溶胶囊(微丸型)的有关物质。采用AgilentZORBAX(4.6mm×250mm,5μm)色谱柱,流动相采用0.015mol/L磷酸氢二钠溶液(用磷酸调节pH值至6.0)-乙腈(v∶v=65∶35),等度洗脱,流速为1.0mL/min,柱温:30℃,检测波长为290nm。该色谱条件下,主成份与已知杂质分离度良好。雷贝拉唑钠的检测限为3.3μg/mL,定量限为10μg/mL,是供试品进样量的0.33%和1.00%,满足杂质检测和控制。通过稳定性的考察,供试品溶液不稳定,需要现用现配。该方法简单、快速、准确,可用于雷贝拉唑钠肠溶胶囊(微丸型)的质量控制。     

HPLC法测定胃镜消泡剂中羟苯乙酯钠含量

采用高效液相色谱(HPLC)法测定胃镜消泡剂中羟苯乙酯钠的含量,色谱条件：采用Kromasil C₁₈色谱柱(250 mm×4.6 mm,5μm),以甲醇-1%冰乙酸溶液(60∶40)为流动相,流速为1.0 mL·min^-1,检测波长为256 nm,柱温为30℃。结果表明：羟苯乙酯钠在2.41～24.14μg·mL^-1范围内线性关系良好(r=1.000 0),平均回收率为107.02%,RSD为1.37%。该方法简便、准确,可用于胃镜消泡剂中羟苯乙酯钠的含量控制。     

顶空气相色谱法测定延胡索酸泰妙菌素中有机溶剂残留量

采用顶空气相色谱法,测定延胡索酸泰妙菌素原料药中甲醇和乙酸乙酯有机溶剂的残留量。结果表明,甲醇和乙酸乙酯在设定范围内有较好的线性,其r值分别为0.9999和0.9998,平均回收率分别为100.1%和99.6%,相对标准偏差分别为1.12%、1.07%。该方法灵敏准确,重现性好,适用于延胡索酸泰妙菌素原料药中有机溶剂残留量的测定。     

超高效液相色谱-串联质谱法测定鸡蛋中泰妙菌素残留

研究建立了对鸡蛋中泰妙菌残留的超高效液相色谱-串联质谱检测方法。试料中的残留药物用0.1%酒石酸提取后,使用正己烷脱脂净化,供液相色谱-串联质谱仪测定,外标法定量。本方法快速、灵敏、重现性好、各项技术指标均满足国内外相关法规要求。适用于鸡蛋中泰妙菌的残留检测。     

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.