亚单位流感疫苗中裂解剂壬苯醇醚-9含量两种检测方法的比较

目的比较高效液相色谱法(HPLC)和紫外分光光度法检测亚单位流感疫苗中裂解剂壬苯醇醚-9含量的效果。方法分别采用HPLC法和紫外分光度法检测亚单位流感疫苗中间体和成品中壬苯醇醚-9的含量,并取中间体进行SDS-PAGE分析。结果紫外分光光度法测定亚单位流感疫苗成品和中间体的壬苯醇醚-9含量比HPLC法高10%以上,测定中间体3壬苯醇醚-9含量的结果差异更显著;SDS-PAGE分析显示中间体1、2、3的核蛋白(NP)含量差异显著,大多数存在于中间体3中。结论 HPLC法可代替紫外分光光度法检测亚单位流感疫苗中裂解剂壬苯醇醚-9的含量。     

露水草提取物β-蜕皮激素含量分析

采用紫外分光光度法并结合HPLC面积归一化法,测定了露水草提取物中β-蜕皮激素的含量。用紫外分光光度法测定的含量,乘以HPLC面积归一化法中的面积百分比,测定了4个露水草提取物中β-蜕皮激素样品的含量。结果表明,本方法测定得到的4个样品的含量分别为45.42%,50.09%,63.18%,52.85%;与高效液相色谱法分析结果(45.72%,50.32%,63.38%,53.11%)相比,相对误差均小于1%。该方法分析准确,简单易行,适用于测定露水草提取物中β-蜕皮激素含量。     

2,4-滴中游离酚的检测方法对比分析

采用4-氨基安替比林分光光度法,在波长520 nm下检测2,4-滴中游离酚的吸光度,通过校准曲线计算含量。采用高效液相色谱法,以甲醇-水为流动相,使用Aglient C_(18)(5μm)为填料的不锈钢柱和紫外检测器,检测波长240 nm下检测2,4-滴中游离酚含量。通过多批次产品测定对比,测定结果无明显差异。高效液相色谱法标准偏差为0. 002,变异系数为1. 33%,平均回收率为99. 6%。     

分光光度法测定银杏叶提取液中总黄酮含量

采用分光光度法测定银杏叶提取液中总黄酮含量.检测波长为415 nm,在6.32×10-4～0.476 g/L的浓度范围内,黄酮含量(c)与吸光度(A)呈良好的线性关系,回归方程为A=4.748c 0.0091(n=7),线性相关系数r=0.999,平均回收率和相对标准偏差分别为103.2%、0.02%(n=6),方法简单快速、准确.     

磷矿石中微量钼的测定—结晶紫分光光度法

测定微量钼的分光光度法很多,但都是用于含量在10~(-3)%以上的样品,对于复杂矿物中含量在10~(-4)～10~(-5)%范围内的分光光度法尚未见有报导.本文研究根据文献[2]的显色反应和条件采用结晶紫分光光度法测定磷矿石中微量     

液体荧光增白剂中尿素含量的测定

荧光增白剂中尿素的测试方法有丁二酮肟分光光度法和高效液相色谱法。对两种方法进行比较研究,结果显示:丁二酮肟分光光度法RSD为4.17%,回收率在60%～90%,显色结果不稳定、精密度和准确度较差;而高效液相色谱法RSD为0.98%,回收率95%～102%,精密度好、准确度高,适合荧光增白剂中尿素含量的测试。     

三聚氰胺甲醛树脂中游离甲醛的测定分析

建立了用分光光度法测定三聚氰胺甲醛树脂中游离甲醛含量的方法。以乙酰丙酮-乙酸-乙酸铵溶液为显色剂,进行显色测定。实验结果表明,该方法在甲醛的浓度为5.2×10~(-6)～32.9×10~(-5)g/mL间与吸光度成良好的线性关系(R~20.9999),测定的相对偏差在5%以内。实验表明该法准确,快捷,操作简便,应用于三聚氰胺甲醛树脂中游离甲醛含量的测定,取得了很好的结果。     

水中甲醛含量的测定方法研究

参照乙酰丙酮分光光度法检测水中甲醛含量和高效液相色谱法检测环境空气中醛类化合物的方法,制定出一种高效液相色谱法检测水中甲醛含量的方法。方法检测限为0.0015μg/m L,平均回收率为99.73%,准确度良好。同时将该法与乙酰丙酮分光光度法进行比较,发现高效液相色谱法不受其他醛类的干扰,结果相对更加可靠准确,因此适用于准确度要求较高的水中甲醛含量的测定。     

15%福美双·吡虫啉·烯唑醇悬浮种衣剂的RP-HPLC分析

采用反相高效液相色谱法(RP-HPLC),使用YWG C18柱和二极管阵列检测器,以甲醇-水为流动相,检测波长260nm,用外标法测定了福美双·吡虫啉·烯唑醇悬浮种衣剂中3种成分的含量.结果表明,该方法的标准偏差为7×10-5-9×10-4,变异系数为1.00%～3.05%,平均回收率分别为96.15%～102.00%、100.00%～105.92%、97.05%～102.92%.该法操作简单快速,定量准确可靠.适用于产品的常规分析和质控研究.     

离子选择电极测定钾肥中钾含量的方法研究

探讨了利用离子选择电极法测定钾肥中钾含量的方法.提出了离子选择电极法在测定钾肥中的新用途.其检出限为2.63×10-6moL/L,相对标准偏差为2.20%～2.35%,回收率为94.88%～97.95%.用国际标准方法--四苯硼酸钠重量法、紫外-可见分光光度法和离子选择电极法对腐植酸钾及普通化肥中的钾含量进行测定,并对...     

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.     

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.     

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.