氧弹燃烧—离子色谱法测定韭菜和韭黄中硫、氮、氯的含量

本实验通过氧弹燃烧法分别对韭菜和韭黄进行燃烧,用过氧化氢碱性水溶液进行吸收,并用离子色谱法对样品中Cl-、NO2-、NO3-、SO42-的含量进行分离测定。通过对韭菜和韭黄的阴离子含量测定、分析,为进一步研究不同栽培条件对蔬菜阴离子含量的影响提供参考。     

离子色谱法测定工业污水中的无机阴离子

采用瑞士万通IC-883型离子色谱仪,Metrosep A Supp4-250型阴离子分析柱,选用1.8 mmol/L Na_2CO_3和1.7 mmol/L NaHCO_3为淋洗液,50 mmol/L H_2SO_4为再生液,建立了用离子色谱法测定工业污水中的无机阴离子含量的分析方法。该方法具有良好的线性关系(0～10 mg/L范围内相关系数为0.999),样品加标回收率在99%～102%之间,相对标准偏差均小于2%。实验表明:该方法操作简单、灵敏度高,可用于工业污水中无机阴离子的检测分析。     

固相萃取-离子色谱法测定土壤中三种有效阴离子

探讨离子色谱法测定土壤中PO43-、Br-、NO2-等有效阴离子的可行性以及相关的前处理方法。采用固相萃取技术处理土壤样品,应用离子色谱法测定土壤中的三种有效阴离子。多次重复测定标准物质PO43-、Br-、NO2-三种有效阴离子,验证方法可行性,测得峰面积的相对平均标准偏差分别为2.02%,0.67%,1.40%。测得土壤中PO43-、Br-、NO2-三种有效阴离子的检出限分别为0.1,1.0,1.0 mg/kg,平均回收率分别为97.82%,96.35%,97.82%。通过一定前处理方法,减少土壤中杂质对测定的干扰和对色谱柱的污染,优化了三种阴离子的色谱分离和测定条件,准确测定了土壤中三种阴离子含量。固相萃取-离子色谱法测定土壤中三种有效阴离子方法简便、快速、灵敏度高。     

氧瓶燃烧-离子色谱法测定桂花中氯、氮、硫的含量

采集潮州湘桥区和潮安区的桂花样品经行氧瓶燃烧,把桂花中的氯、氮、硫元素转换为阴离子,用含有过氧化氢碱性水溶液进行吸收,再通过离子色谱测定样品中Cl-、NO2-、NO3-、SO42-的含量,以此来分析不同地区的桂花的生长环境对桂花中氯、氮、硫的含量的影响。     

N-甲基-2-吡咯烷酮有机试剂中微量阴离子杂质的分析

高纯度的化学试剂是许多食品分析、制药分析、工业制造等行业中的关键性基础化工材料之一,其中微量杂质的分析是发展这类试剂产业的关键技术环节之一。建立了高纯度有机试剂中的3种阴离子的离子色谱定量分析方法,分别以5和20 mmol/L NaOH为流动相,Ionpac AS 11-HC阴离子通用分析柱进行分离,电导检测器检测,可以实现HPLC级甲醇样品中添加的Cl-、SO2-4和NO-3的含量分析。该方法3种离子的线性范围在5~100μg/L之间,3种阴离子的最低检出浓度分别为2(Cl-)、5(SO2-4)和5μg/L(NO-3),方法的回收率为93%~107%,相对标准偏差(RSD)为2.0%~3.5%。此外,我们还进一步考察了前处理方法中采用WAX固相萃取技术对色谱纯的N-甲基-2-吡咯烷酮试剂中的阴离子进行富集,可以实现该样品中上述3种阴离子的分析检测。     

氧瓶燃烧—离子色谱法测定车前草中氟、氯、氮、硫的含量

利用氧瓶燃烧法对两种生长环境不同(分别为生长在公路边和山上)的车前草全草和车前草种子车前子样品进行燃烧,用含过氧化氢碱性水溶液进行吸收,并用离子色谱法对样品中F-、Cl-、NO-2、NO-3、SO2-4等5种阴离子含量进行分离测定;实验采用AS23型阴离子分析柱(250mm×4mm),AG23型保护柱(50mm×4mm);通过流速为1.0mL/min的4.5m mol/L Na2CO3+0.8m mol/L NaHCO3淋洗液进行洗脱。结果表明:车前草全草和车前子样品中均未检测出NO-2;同一种离子在不同样品中的含量各有差异。本实验方法简单、准确、可靠,具有较好的实用性,同时为车前草和车前子中阴离子含量的检测提供依据,为进一步开发车前草,研制车前草制剂提供了参考。     

氧弹燃烧—离子色谱法测定艾草中氟、氯、氮、硫的含量

利用氧弹燃烧法对艾草中的叶、根、茎样品进行燃烧,用含过氧化氢碱性水溶液进行吸收,并用离子色谱法对样品中F-、Cl-、NO2-、NO3-、SO42-等5种阴离子含量进行分离测定;实验采用AS23型阴离子分析柱(250mm×4mm),AG23型保护柱(50mm×4mm);通过流速为1.0ml/min的4.5m mol/L Na2CO3+0.8m mol/L Na HCO3淋洗液进行洗脱。结果表明:艾草的叶、根、茎样品中均未检测出F-;同一种离子在不同样品中的含量各有差异。本实验方法简单、准确、可靠,具有较好的实用性,同时为艾草中的叶、根、茎中阴离子含量的检测提供依据,为进一步开发艾草,研制艾草精油提供了参考。     

离子色谱法测定水质中的无机阴离子

建立了离子色谱法测定水质中的无机阴离子（F-、Cl-、NO2-、NO3-、PO43-、SO42-）的方法。对方法的线性、检出限、精密度及水质质控样品进行了分析,结果表明,6种阴离子线性良好,相关系数为0.9994～1.000,方法检出限为0.001 mg/L～0.009 mg/L,测定6次平行试样的相对标准偏差小于2.61%,质控样品测定结果均在范围内。该方法能够满足水质中6种阴离子的检测要求。     

离子色谱法测定环境空气中F~-、Cl~-、NO_2~-、NO_3~-、SO_4~(2-)五种水溶性阴离子

建立了离子色谱法测定环境空气中水溶性阴离子。F~-、Cl~-、NO_2~-、NO_3~-、SO_4~(2-)五种水溶性阴离子的方法检出限分别为0.010 ug/m~3、0.010 ug/m~3、0.005 ug/m~3、0.010 ug/m~3、0.025 ug/m~3,精密度(RSD,n=6)为0.1%～5.4%,实际样品测定样品加标回收率在82.4%～103%。实验结果表明,该方法准确可靠、灵敏度好,适用于环境空气中五种水溶性阴离子的分析测定。     

离子色谱法同时测定透析用水中痕量氟、氯、硫酸根和硝酸根

该文介绍了离子色谱法同时测定透析用水中痕量的F-、Cl-、SO2-4和NO-3等阴离子的方法;对样品进样量、淋洗液浓度、检测器电流等条件进行了优化,有效地提高了灵敏度,降低各阴离子的检出限,F-、Cl-、SO2-4和NO-3的方法检出限依次为0.012、0.014、0.074和0.016 mg/L,加标回收率为90%~110%;对环境标准204715进行了6次测试,各阴离子浓度在推荐值的两倍不确定度范围内,相对标准偏差RSD2%。该方法具有灵敏、准确、快速等优点,可用于透析用水中4种阴离子的同时分析。     

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.     

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。     

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.