毛细管气相色谱法分析甲酚异构体

建立一种测定邻甲酚、间甲酚和对甲酚的毛细管气相色谱分析方法。邻甲酚和间甲酚的峰面积与浓度在2~200g/L范围内呈线性关系,相对标准偏差分别为1.84%、1.67%;对甲酚在2~210g/L范围内呈线性关系,相对标准偏差为1.63%,测定回收率均在96.4%~103.8%。     

HPLC-FLD/DAD双检测器串联测定面膜中10种荧光增白剂

建立了一种应用高效液相色谱仪(HPLC)-FLD/DAD双检测器串联测定面膜中10种荧光增白剂的方法。采用Welch Ultimate LP C_(18)(4.6 mm×250 mm,3.5μm)色谱柱分离,以甲醇-0.05 mol/L磷酸二氢铵水溶液为流动相梯度洗脱,流速1.0 m L/min,柱温35.0℃,荧光检测器(FLD)激发波长360 nm,发射波长430 nm,二极管阵列检测器(DAD)测定波长360 nm。结果表明,10种荧光增白剂在各自的线性范围内线性关系良好,相关系数均大于0.999 5。在3个加标水平下,10种荧光增白剂的平均回收率为87.6%~114.2%,RSD均小于5.0%(n=6)。10种荧光增白剂检出限:FLD为0.026~0.40 mg/kg,DAD为0.50~2.7 mg/kg。     

荧光法测定餐具洗涤剂中的荧光增白剂

对荧光法测定餐具洗涤剂中的荧光增白剂进行了研究,建立了标准加入荧光法检测餐具洗涤剂中荧光增白剂的定量分析方法。33号荧光增白剂激发波长341 nm,发射波长438 nm,线性范围0.004⁰.1 mg/L,在此范围内曲线相关系数0.998 60.1 mg/L,在此范围内曲线相关系数0.998 6¹,方法检出限为0.01μg/g,定量限为0.03μg/g,回收率为96%1,方法检出限为0.01μg/g,定量限为0.03μg/g,回收率为96%¹01%,相对标准偏差RSD为1.9%101%,相对标准偏差RSD为1.9%⁴.9%。结果显示标准加入荧光法准确可靠、简便、灵敏度高,消除了基质中荧光物质和助剂的影响,可应用于餐具洗涤剂中荧光增白剂的检测。     

高效液相色谱法同时测定化妆品中12种美白成分

采用高效液相色谱法(HPLC)同时测定化妆品12种美白成分。样品经质量分数50%甲醇溶液提取、过滤后,进行HPLC分析。色谱柱为Phenomenex Luna C18(2)柱(4.6 mm×250 mm×5μm)。流动相组成为甲醇-0.02 mol/L KH2PO4溶液,梯度洗脱。流速为1.0 m L/min。二极管阵列检测器,L-抗坏血酸-2-磷酸酯镁、鞣花酸及甘草酸二钾的检测波长为254 nm,烟酸、曲酸、氢醌、烟酰胺、树莓苷、4-甲氧基水杨酸钾、苯酚、杜鹃醇和苯乙基间苯二酚的检测波长为220 nm。结果发现,12种美白类成分均在0.5~50μg/m L范围内线性关系良好(相关系数r0.999),霜类、乳液类、水剂类3种化妆品基质中12种美白成分的回收率(添加水平分别为20、50和200μg/g)在85.6%~111.9%之间,相对标准偏差(RSD)在0.4%~8.9%范围内,最低检出质量比在0.3~1.5μg/g之间。     

电还原邻硝基苯酚合成邻氨基苯酚的高效液相色谱分析法

建立了一种反相高效液相色谱法同时测定邻硝基苯酚和邻氨基苯酚的新方法。采用Shim-pack VP-ODS(250 mm×4.6 mm,4.6μm)色谱柱,选用纯甲醇为流动相,以285 nm为检测波长,流速为0.8 m L/min,柱温为35℃,以外标法进行定量分析。实验结果表明,邻硝基苯酚和邻氨基苯酚的质量浓度在1.0~40.0μg/m L范围内呈良好的线性关系,其相关系数分别为r=0.999 5(n=9)和r=0.999 8(n=9),测定其在10.0、20.0和30.0μg/m L这3个不同质量浓度下的方法精密度,其相对标准偏差分别≤1.28%和≤1.04%。将本方法应用于以邻硝基苯酚为原料电解合成邻氨基苯酚反应液的分析,其加标回收率分别在93.0%~105.6%和90.6%~106.2%之间,相对标准偏差分别≤3.75%和≤1.44%。实验结果表明,该方法可用于邻硝基苯酚和邻氨基苯酚两种组分的同时测定。     

亲水作用液相色谱法同时测定美白化妆品中的α-熊果苷和β-熊果苷

采用亲水作用液相色谱法同时测定美白化妆品中α-熊果苷和β-熊果苷的含量。样品经乙腈提取,用色谱柱Waters UPLC BEH Amide柱(100 mm×2.1 mm×1.7μm)分析。流动相为乙腈-水(体积比93︰7)。流速为0.3 m L/min。采用荧光检测器,激发波长为283 nm,发射波长为330 nm。α-熊果苷、β-熊果苷响应值均在2~2 000 ng/m L范围内线性关系良好(r0.999);在霜类、乳液类、水剂类3种化妆品空白基质中,α-熊果苷、β-熊果苷的添加水平为0.05、1.00和20.00μg/g时,平均回收率在91.5%~96.5%之间(n=6,相对标准偏差≤6.1%)。定量下限均为0.05μg/g。本方法简便、快速、灵敏,可用于美白化妆品中α-熊果苷、β-熊果苷的同时定量测定。     

荧光分析法测定芒果叶总黄酮含量的研究

采用荧光分析法测定芒果叶中总黄酮含量。根据Al3+与黄酮类化合物形成稳定的荧光络合物,以芦丁为标样,采用低共熔溶剂作为提取溶剂,对芒果叶总黄酮进行微波辅助提取,选择激发波长λex=436 nm、发射波长λem=483 nm条件下,测定四种品种的芒果叶中总黄酮含量。该方法检测限为0.12μg/m L,线性范围在0.16~0.80μg/m L之间,线性方程为:y=11.41+1789.2x,线性相关系数为r=0.9989,回收率为97.2%~102.5%,相对标准差(RSD)为1.39%。荧光分光光度法测定芒果叶中总黄酮含量准确度较高,操作简便,成本低。     

荧光法测定餐具洗涤剂中的荧光增白剂

对荧光法测定餐具洗涤剂中的荧光增白剂进行了研究,建立了标准加入荧光法检测餐具洗涤剂中荧光增白剂的定量分析方法。33号荧光增白剂激发波长341 nm,发射波长438 nm,线性范围0.004~0.1 mg/L,在此范围内曲线相关系数0.998 6~1,方法检出限为0.01μg/g,定量限为0.03μg/g,回收率为96%~101%,相对标准偏差RSD为1.9%~4.9%。结果显示标准加入荧光法准确可靠、简便、灵敏度高,消除了基质中荧光物质和助剂的影响,可应用于餐具洗涤剂中荧光增白剂的检测。     

高效液相色谱法测定牛奶中磺胺类药物残留

建立了高效液相色谱法同时测定牛奶中十种磺胺类药物残留量。样品用5%高氯酸溶液进行沉淀蛋白,经HC-C18柱(250 mm×4.6 mm,5μm)分离,甲醇-2%乙酸流动相体系梯度洗脱,用紫外检测器进行检测,检测波长为270 nm,外标法定量。结果表明:10种化合物在0.10~2.0μg/m L浓度范围内线性关系良好,相关系数为0.9921~0.9999。添加水平为0.20,0.40,1.0μg/m L时,平均回收率为81.6%~105%。方法预处理简单,适用于牛奶中磺胺类抗生素药物快速筛查。     

气相色谱法测定双组分美缝剂中甲酚异构体

借助气相色谱仪,建立了双组分美缝剂中邻甲酚、对甲酚和间甲酚3种异构体含量的测定方法。样品以乙腈为溶剂,用RTX-WAX(30m×0.25 mm×0.25μm)毛细管色谱柱分离,氢火焰检测器(FID)检测。研究表明,3种甲酚异构体具有较好的分离效果,在4 mg/L～100 mg/L的浓度范围内具有良好的线性,相关系数均大于0.999;回收率为97.1%～102.1%,相对标准偏差(RSD)均小于2.0%;精密度(RSD)为1.35%～1.63%;检出限为2.8 mg/kg～4.8 mg/kg。该方法简单便捷,具有良好的精密度和重复性,可为双组分美缝剂中甲酚异构体含量的测定提供一定的理论参考。     

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。