异烟酸-巴比妥酸法测定尿中硫氰酸盐

根据尿中硫氰酸盐的吡啶-巴比妥酸分光光度法结合工作场所中氰化氢和氰化物测定方法,建立了异烟酸-巴比妥酸法测定尿中的硫氰酸盐。该方法检出限为0. 17μg,方法的最低检出浓度为1. 7 mg/L(按取0. 1 m L尿样计);相对标准偏差范围:1. 25%～1. 99%,样品加标回收率为98. 5%～103%。该方法安全度高、重现性好、准确度高,且符合尿液中的硫氰酸盐的测定要求,值得推广。     

流动注射法测定饮用水中氰化物

水中氰化物经在线蒸馏被碱性溶液吸收,与氯胺-T作用生成氯化氰,再与异烟酸-巴比妥酸反应生成紫蓝色染料;采用流动注射法测定水中弱酸可分离的氰及游离氰,检测范围1～100μg/L,检出限0.25μg/L;对方法精密度、准确度、饮用水中干扰物质的影响、加标回收进行了试验,结果令人满意.     

流动注射仪氰化物分析模块的改进

对LACHAT QC8000型流动注射仪氰化物分析模块进行了优化。在总氰化物分析模块的基础上,选用易挥发性氰化物异烟酸-巴比妥酸分光光度法,实现了易挥发性氰化物与总氰化物分析的简易转换。在2～200μg/L的线性范围内,相关系数r0.999,检出限为0.22μg/L,易挥发性氰化物加标回收率为96.0%～104%,总氰化物加标回收率为98.8%～105%。     

异烟酸-巴比妥酸分光光度法测定尿硫氰酸盐

在弱酸性介质中及氯胺T存在条件下,SCN~-可与异烟酸-巴比妥酸形成一紫蓝色染料,该染料最大吸收波长位于598nm,且其吸光度A与SCN~-含量在一定的范围内呈良好的线性关系,据此我们建立了测定人尿中微量SCN~-的异烟酸-巴比妥酸分光光度法,本法SCN~-含量均在0～2.50μg/5.0mL范围内符合比耳定律,方法用于人尿中微量SCN~-的测定,结果令人满意。     

流动注射-分光光度法测量总氰化物的研究

通过流动注射分析仪实验，检验水中总氰化物，在酸性条件下，样品经140℃高温高压水解及紫外消解，释放出的氰化氢气体被氢氧化钠溶液吸收。吸收液中的氰化物于氯胺T反应生成氯化氰，然后与异烟酸反应水解生成戊稀二醛，再与巴比妥酸作用生成蓝紫色化合物，于600 nm波长处测量吸光度，根据测定结果分析仪器方法的标准曲线相关系数，分析仪器方法检出限、精密度、准确度。实验结果表明，流动注射分析仪在测量水中总氰化物时，总氰化物质量浓度在0.0～200.0μg/L范围内线性关系良好；流动注射分析法测定总氰化物的检出限为0.8μg/L,低于标准方法检出限0.001 mg/L;流动注射-分光光度法测定总氰化物精密度在1.11%～1.92%之间，满足标准方法要求的小于20%;有证标准样品测试中，测定相对误差分别为5.31%和4.16%,在实际样品加标测试中，加标回收率在96.1%～103%之间，能满足标准方法要求。因此，流动注射-分光光度法测定总氰化物能够满足常规水体中总氰化物的检测要求。     

流动注射分光光度法测定生活饮用水中氯化氰

采用流动注射分光光度法测定生活饮用水中CNCl。CNCl与异烟酸-巴比妥酸反应,生成紫蓝色染料,在600 nm处比色测定,测定范围是0.01～0.80 mg/L（以CN-计）,检测限为0.002 mg/L（以CN-计）,每小时能测定40个样品,加标回收率为98.8%～101.2%,相关系数r=0.999 99。     

渔业水质中总氰化物的测量不确定度评定

对异烟酸-巴比妥酸分光光度法测定渔业水质中总氰化物含量的不确定度进行评定。分析了不确定度的主要来源,包括测量重复性、标准溶液配制、定容体积和检测设备引入的不确定度。分别计算了各分量的不确定度,再计算出合成标准不确定度和扩展不确定度。结果表明,异烟酸-巴比妥酸分光光度法测定渔业水质中总氰化物含量的扩展不确定度为0.0004 mg/L(k=2)。     

预蒸馏—异烟酸—巴比妥酸光度法测定土壤中的总氰化物

文章主要提出利用预蒸馏-异烟酸-巴比妥酸光度法对土壤中的总氰化物进行测定。蒸馏预处理过程改用硫酸代替磷酸使得预处理效果更好;采用更合适的分析方法—异烟酸-巴比妥酸光度法。     

在CTMAB存在下，异烟酸-硫代巴比妥酸显色光度法测定尿液中硫氰酸盐

在弱酸性介质中及溴化十六烷基三甲铵(CTMAB)和氯胺T存在条件下,硫氰酸盐(SCN~-)与异烟酸-硫代巴比妥酸形成一蓝绿色染料,其最大吸收波长位于648 nm,ε=4.30×10~4L·mol~(-1)·cm~(-1),且其吸光度A与SCN~-含量在一定的范围内呈良好的线性关系,建立了测定人尿中微量SCN~-的异烟酸-硫代巴比妥酸-CTMAB显色光度法,本法SCN~-含量在0～6.0μg/5.0 mL范围内符合比耳定律,方法用于人尿中微量SCN~-的测定,结果令人满意。     

流动注射仪测定水中氰化物两种显色法的比较

使用流动注射分析仪分别用吡啶-巴比妥酸和异烟酸-巴比妥酸两种显色方法对水中氰化物进行检测。吡啶-巴比妥酸法检测速度更快,更加适用于大规模检测和水污染事故等应急监测;异烟酸-巴比妥酸法检出限更低,且不需使用吡啶,有利于保护实验人员身心健康。这两种方法均有检测效率高、准确率高、灵敏度高、稳定性高等多种优点。     

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。