离子对高效液相色谱法分析化妆品中的曲酸

建立了化妆品中曲酸(KA)的离子对高效液相色谱法。采用0．01mol／L磷酸氢二钠-甲醇(95：5,V／V)为流动相,添加1．0mmol／L四丁基溴化胺(TBA),检测波长226nm,样品用40％甲醇超声提取,曲酸在Nova-Pak C18柱上获得了良好分离。该方法的检出限为0．024mg／L,回收率为93．9％～101．2％,相对标准偏差为0．97％～1．81％。     

反相高效液相色谱法测定N-β-氰乙基苯胺的研究

建立了测定N—β-氰乙基苯胺的反相高效液相色谱法。固定相为SPHERIGEL ODS C18柱，流动相为甲醇—(1‰磷酸—0．01mol/L磷酸氢二钾)，体积比1：1，检测波长240nm。该法线性范围0．01—20mg，回归方程为A＝20571．6m 5408．5，相关系数0．9991，相对标淮偏差1．23％(c＝0．6mg／mL，n＝10)，检出限3μg，加标回收率为98．6％～102．0％。     

环境中异丙草胺农药残留分析方法

建立了新型除草剂异丙草胺在环境水及土壤中的残留分析方法。水样用二氯甲烷提取后即可进样测定;土样用石油醚：丙酮=1：1(v／v)的混合液提取,石油醚液液分配,氟罗里硅土层析柱净化,然后GC-ECD行检测。水及土壤中异丙草胺残留方法的最小检测浓度分别为0．2μg／L和1．8μg／kg,回收率在85.7％～102.6％之间,变异系数为1．3％～6．6％。     

SBR法处理德士古煤气化废水的脱氮功效和影响因素

采用SBR工艺对德士古气化生产甲醇产生的废水处理,结果表明：在碳、氮、磷比例理想的情况下,达到了既去除有机物又能脱氮的效果。当总停留时间控制在5～9h、污泥负荷为0．041～0．096kgBOD5／（kgMLSS·d）时,出水BOD5浓度为0-30mg／L,去除率达88％～89％;出水COD浓度为10．7～32．2mg／L,去除率达87％～89％;出水NH3-N浓度为2．83～9．23mg／L,去除率达95％～97％。     

充气糖果中胭脂红酸的高效液相色谱测定

建立充气糖果中胭脂红酸的高效液相色谱方法。糖果经乙醇／氨杉水超声提取,水浴蒸至近干,氨水溶液定容。采用C18柱（4．6mm×250mm,5μm）,流动相为0．01％磷酸溶液和甲醇／乙腈,梯度洗脱,流速1．0mL/min,检测波长494nm。胭脂红酸在2．5—40．0mg／L线性良好,回收率为87％～102％,RSD为1．75％,检出限为0．3mg／kg。该方法操作简便、准确,适于充气糖果中胭脂红酸的测定。     

丁烯氟虫腈在大米中残留分析方法的研究

研究并建立丁烯氟虫腈在大米中残留分析方法。样品以乙腈为提取剂,氨基固相萃取柱净化,甲醇和二氯甲烷（v／v,1／99）洗脱,供气相色谱测定。对大米样品进行添加回收率实验,分别添加0．10mg／kg、0．50mg／kg、2．0mg／kg,回收率在71．9％～98．2％之间,变异系数为2．78％～10．6％。方法的准确性、灵敏度均达到农药残留分析的要求。     

高效液相色谱法分析丁硫克百威及其降解产物

建立丁硫克百威及其降解产物(克百威、3-羟基克百威)的高效液相色谱分析方法.液相色谱条件:流动相为甲醇-水(体积比50:50),流速1.0mL／min,C18柱,紫外检测器波长269 nm,进样体积10．0 μL.利用峰高进行外标法定量分析,线性相关系数大于0．999．检出限5．5～18.2μL／L.丁硫克百威、克百威和3-羟基克百威峰高值的变异系数分别为0．45％、0.86％、1.11％.回收率分别为102.4％～103.3％、106.9％～108.4％、102.6％～104.7％.丁硫克百威及其降解产物可同时检测和定量分析.     

RP-HPLC法测定护肤品中自藜芦醇的含量

建立RP—HPLC测定化妆品中自藜芦醇含量的方法。色谱柱为Shimadzu ODSC18柱（4．6mm×150mm,5m）,流动相为甲醇：0．05％磷酸水溶液（50：50）,等度洗脱,检测波长306nm,流速1mL／min,上样量10μL,柱温为室温。结果表明白藜芦醇在0～200mg／L呈良好的线性关系,相关系数为0．9997,护肤品样品平均加标回收率为98．8％,相对标准偏差为2．06％。本方法操作简便,结果准确可靠,适于化妆品中白藜芦醇的含量测定。     

高效液相色谱定量分析2,6-二硝基氯苯-4-磺酸

本文报导了高效液相色谱法定量分析2，6-二硝基氯苯-4-磺酸的方法。采用Diamonsil C18色谱枉，甲醇／水为流动相(60／40)(每500ml流动相中舍有0．30g磷酸二氢钾)，检测波长为215nm，线性范围19.83mg／L～99.16nm／L，r=0.9999；标准偏差为0．16，回收率为99．50％～100．10％。     

反相离子对高效液相色谱法测定巴丹

建立了用反相离子对色谱法测定农药巴丹含量的方法。色谱柱为ODS C18柱,流动相为含1．0mmol/L十二烷基硫酸钠的甲醇／水（V／V＝70:30)溶液,用磷酸调节溶液pH值在3．3左右。紫外检测波长为225nm。分别考察了流动相中离子对试剂、甲醇浓度以及pH值对巴丹保留时间的影响。峰面积与浓度具有良好的线性关系,相关系数为0．0005,平均回收率为100．0％。方法简便、快速、准确,可用于巴丹原药的测定。     

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.     

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.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.