曙红亚甲基蓝分光光度法测定水中阳离子表面活性剂

采用分光光度法测定水样中阳离子表面活性剂的含量。在弱酸性的HCl-NaAc缓冲介质中,阳离子表面活性剂十六烷基溴化吡啶(CPB)以及十六烷基三甲基溴化铵(CTAB)能与曙红亚甲基蓝反应,形成离子缔合物,后者的最大吸收波长分别为660 nm和658 nm,且阳离子表面活性剂的浓度与溶液的显色程度呈良好线性关系。在最大吸收波长处,CPB和CTAB的浓度分别在0~2.10×10-5mol/L和0~1.98×10-5mol/L范围内遵守比尔定律,表观摩尔吸光系数分别为1.79×104L/(mol.cm)和1.38×104L/(mol.cm),检出限分别为8.27×10-7mol/L和9.88×10-7mol/L,平均回收率为99.5%~102.6%。方法具有较高的灵敏度和良好的选择性,可用于水样中阳离子表面活性剂的测定。     

基于紫外-可见吸收光谱法检测药物中地奥司明

在pH 6. 70的弱酸性溶液中,乙基紫与地奥司明反应生成一种二元配合物,在紫外光区345 nm处产生1个较强的正吸收峰,在可见光区594 nm处产生1个较强的负吸收峰,在此二波长处,地奥司明的质量浓度在0. 3～15. 2 mg/L范围内与吸光度的绝对值(|A|)呈线性关系并服从朗伯-比尔定律,其表观摩尔吸光系数(κ)为1. 88×10~4L/(mol·cm)(正吸收)和3. 81×10~4L/(mol·cm)(负吸收),检出限为0. 24 mg/L(正吸收)和0. 18 mg/L(负吸收)。当以负吸收为参比波长、正吸收为测定波长、用双波长法测定时,其线性范围不变,表观摩尔吸光系数(κ)为5. 70×10~4L/(mol·cm),检出限为0. 11 mg/L。由此建立了测定地奥司明的紫外-可见吸收光谱法。该方法可用于市售地奥司明药物中地奥司明的测定。     

偶氮氯膦Ⅲ探针吸收光谱法测定药物中的卡马西平

建立了简便、快速、准确测定卡马西平的单波长和双波长可见吸收光谱法,探讨了反应条件、共存物质的影响及光谱特征。在弱酸性溶液中,偶氮氯膦Ⅲ与卡马西平以静电引力结合生成具有2个正吸收峰的离子缔合物,最大和次大正吸收波长分别为614 nm和666 nm,在此2个波长处,卡马西平的质量浓度在0~4.7 mg/L范围内与吸光度A呈线性关系,服从朗伯-比尔定律,表观摩尔吸光系数(κ)分别为1.58×10~4L/(mol·cm)(614 nm)和1.20×10~4L/(mol·cm)(666 nm)。用双波长叠加法测定时,其表观摩尔吸光系数(κ)达2.78×10~4L/(mol·cm),方法的回收率为98.0%~102%,相对标准偏差RSD(n=5)为2.3%~2.7%。该方法可用于药片中卡马西平的测定。     

三波长吸收光谱法测定药物中的氨曲南

在酸性Tris-HCl介质中,氨曲南与甲基绿反应生成具有3个正吸收峰的绿色二元离子缔合物,最大正吸收峰位于661 nm,其他2个吸收峰分别位于565 nm和420 nm,在此三波长处,氨曲南的质量浓度在0～11. 0 mg/L范围内服从朗伯-比尔定律,表观摩尔吸光系数(κ)分别为1. 25×104(420 nm)、1. 91×104(565 nm)、2. 33×104L/(mol·cm)(661 nm),当用双波长叠加法或三波长叠加法测定时,其表观摩尔吸光系数(κ)可达4. 24×104L/(mol·cm)(565 nm+661 nm)和5. 49×104L/(mol·cm)(420 nm+565 nm+661 nm)。由此建立了测定氨曲南的单波长(SWO-VIS)、双波长(DWO-VIS)和三波长(TWO-VIS)吸收光谱法;还探讨了吸收光谱特征、显色反应条件及共存物质的影响。将TWO-VIS法用于氨曲南实际药品的测定,回收率为97. 7%～103%,相对标准偏差RSD(n=5)为2. 1%～2. 7%。     

碱性蓝B探针吸收光谱法测定美司那

在pH 7.93的Britton-Robinson (BR)溶液中,美司那与碱性蓝B反应生成蓝色离子缔合物,光谱曲线上呈现1个强的正吸收峰和1个较强的负吸收峰,正吸收峰位为580 nm,表观摩尔吸光系数(κ)为7.04×10~4 L/(mol·cm),负吸收峰位为430 nm,表观摩尔吸光系数(κ)为1.03×10~4 L/(mol·cm),在此二个波长处,美司那的质量浓度为0～2.7 mg/L范围内服从朗伯-比尔定律,据此建立了测定美司那的正吸收光谱法和负吸收光谱法。该法用于市售美司那药物中美司那的测定,加标回收率为97.9%～98.9%,相对标准偏差(RSD)(n=5)为2.5%～2.8%。     

分光光度法测定水中微量阴离子表面活性剂

在用HCl溶液调节pH=12.0的NaOH溶液中,5-甲基-2-[3-(4-苯基-2-噻唑基)三氮烯基]苯磺酸(MPTTBSA)与氯化十六烷基吡啶(CPC)形成离子缔合物MPTTBSA-CPC。在该溶液中加入阴离子表面活性剂时,能定量置换出离子缔合物中的MPTTBSA,使缔合物在最大吸收波长556 nm处的吸光度下降,阴离子表面活性剂的浓度与溶液的褪色程度呈良好线性关系,从而建立了阴离子表面活性剂光度测定法。实验结果表明,十二烷基磺酸钠(SLS)和十二烷基苯磺酸钠(SDBS)的表观摩尔吸光系数分别为1.24×104 L·mol-1·cm-1和1.07×104 L·mol-1·cm-1,在0～2.5×10-5 mol·L-1范围内服从比尔定律。该方法应用于生活污水中微量阴离子表面活性剂(以SLS计)的测定,结果与亚甲基蓝法测定结果基本一致。     

微波消解二溴邻硝基苯基荧光酮分光光度法测定中草药中痕量锗

在磷酸介质中,建立了以二溴邻硝基苯基荧光酮为显色剂、吐温-80为表面活性剂、在微波消解条件下用分光光度法测定痕量锗的新方法.探讨了测定痕量锗的最佳显色条件和测定条件.配合物最大吸收位于540 nm波长处,其摩尔吸光系数ε=0.886×105L/(mol.cm),线性回归方程A=2.30×10-3ρ-7.1×10-3(ρ的单位为μg/mL),相关系数r=0.999 9,检出极限为7.86×10-9g/mL,结果可以直接用于中草药中痕量锗的测定.     

水杨基荧光酮分光光度法测定合金钢中的钼

研究了水杨基荧光酮在混合表面活性剂CTMAB和OP存在下与Mo(Ⅵ)的显色反应。结果表明,在5mol/L盐酸溶液中,钼与水杨基荧光酮在混合表面活性剂CTMAB和OP存在下,形成橙色配合物,最大吸收波长为525nm,配合物的表观摩尔吸光系数为1.55×105 L/(mol·cm),钼的质量浓度在0~0.5μg/mL符合比尔定律。应用于中低合金钢标样中微量Mo(Ⅵ)的测定,结果令人满意。     

双波长可见吸收光谱法测定盐酸米多君

在弱碱性乙醇溶液中,溴甲酚绿与盐酸米多君以静电引力结合生成具有1个较强正吸收峰和1个较强负吸收峰的二元离子缔合物,最大正吸收峰位于553 nm,最大负吸收峰位于444 nm,表观摩尔吸光系数(κ)分别为2. 06×104L/(mol·cm)(553 nm)和2. 07×104L/(mol·cm)(444 nm)。当用双波长法测定时,表观摩尔吸光系数(κ)可达4. 13×104L/(mol·cm),线性范围均为0. 2～8. 7 mg/L,检出限分别为0. 15 mg/L(单波长法,553 nm)、0. 14 mg/L(单波长法,444 nm)和0. 072 mg/L(双波长法)。据此建立了测定盐酸米多君的双波长可见吸收光谱法,该方法用于盐酸米多君片剂中盐酸米多君的测定,回收率和相对标准偏差RSD(n=5)分别为98. 4%～102%和1. 8%～2. 3%。     

双波长叠加吸收光谱法测定奥扎格雷钠

建立了一种快速、准确测定药物中奥扎格雷钠的双波长吸收光谱法。在弱酸性的Tris-盐酸介质中,奥扎格雷钠与维多利亚蓝B反应生成具有2个明显正吸收峰的蓝色离子缔合物,最大正吸收波长位于668 nm,次大正吸收波长位于512 nm,表观摩尔吸光系数(κ)分别为2.14×104L/(mol·cm)(668 nm)和1.95×104L/(mol·cm)(512 nm),奥扎格雷钠的质量浓度在0.1~5.0 mg/L范围内服从朗伯-比尔定律。当采用双波长叠加法测定奥扎格雷钠时,其表观摩尔吸光系数(κ)可达4.09×104L/(mol·cm)。该方法用于市售奥扎格雷钠药物中奥扎格雷钠含量的测定,结果满意。     

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。