超级微波-ICP-MS法测定不同基质化妆品中总锡含量

建立了以超级微波消解-电感耦合等离子体质谱法(ICP-MS)测定不同基质化妆品中总锡(Sn)含量的方法。方法使用硝酸水溶液和超级微波进行消解,ICP-MS法检测,外标法定量。在最优化的仪器条件下,元素Sn在0~100μg/L范围内的响应线性关系良好,相关系数为1.0000;方法检出限为0.01 mg/kg。方法成功应用于对8种基质化妆品中Sn元素的测定,样品三水平加标回收率在86.0%~111.0%之间,相对标准偏差不超过3.7%。该方法简便快速、准确、灵敏度高,为快速测定不同基质化妆品中的总锡含量提供了有效的分析方法。     

超级微波消解-ICP-MS测定纺织品中8种重金属元素

选取两种不同纺织品样品,用超级微波和传统微波分别进行消解,并通过电感耦合等离子体质谱(ICP-MS)法测定铅、镉、汞、砷、铬、锑、锡、锌8种重金属元素,用内标法进行定量。结果表明:8种元素的检出限为0.01～0.3 mg/kg,定量下限为0.03～1.0 mg/kg;用超级微波消解样品的加标回收率为90.1%～98.6%,相对标准偏差为0.5%～4.7%。该方法操作简便、灵敏度高,每批次可处理的样品量多,可为纺织品中重金属元素的测定提供快速和有效的测定方法。     

超级微波消解-电感耦合等离子体质谱法测定彩妆类化妆品中铅、砷、汞、镉、铬的含量

通过对样品前处理和电感耦合等离子体质谱法（ICP-MS）仪器参数进行优化，采用铼（Re）、铑（Rh）作为内标元素，建立了超级微波消解-ICP-MS同时测定彩妆类化妆品中铅（Pb）、砷（As）、汞（Hg）、镉（Cd）、铬（Cr）5种重金属元素。结果显示，5种重金属元素在一定浓度范围内，线性关系良好，线性方程相关系数均大于0.998，低、中、高浓度加标回收率范围为93.8%～104.1%，相对标准偏差（RSD）为0.84%～6.11%(n=6)，检出限为0.001 7～0.011μg/L，检出浓度为0.21～1.4μg/kg。该方法专属性强、灵敏度高，可快速、准确测定彩妆类化妆品中5种重金属元素。     

微波消解—ICP-MS测定稻米中的铅、砷、汞、镉

探讨了微波消解条件、ICP-MS(电感耦合等离子体质谱)仪器工作条件及影响测定的因素。用微波消解法进行样品的消解,直接用ICP-MS测定稻米样品中的铅、砷、汞和镉4种微量重金属的含量。结果表明,该法对各微量重金属元素的检出限为0.01~0.03μg/L,相对标准偏差为0.3%~3.8%,加标回收率均在90%以上。方法操作简便、分析速度快、灵敏度高,各项分析性能指标均达到要求,用于大米中微量重金属元素的分析,有助于了解和预警稻米的安全性,结果满意。     

微波消解-ICP-MS法同时测定金银花中重金属元素

建立微波消解-电感耦合等离子体质谱法(ICP-MS)测定金银花中5种重金属铅、镉、砷、汞和铜的含量。ICP-MS法有较好的线性关系,相关系数均达到0.9992以上,各元素的检出限在0.01～0.36μg/L,回收率在80.7%～105.6%(n=6)。微波消解-ICP-MS法测定金银花中重金属元素,操作简便,分析快速,灵敏度和准确度高,适用于金银花药材的质量控制,监控金银花药材中的重金属元素含量。     

超级微波消解-电感耦合等离子体质谱法测定化妆品中40种元素

建立同时测定化妆品中40种元素的超级微波消解-电感耦合等离子体质谱法。样品经超级微波消解,采用电感耦合等离子体质谱法测定,在线内标校正,外标法定量。方法学验证,对146批样品进行了测定和检测结果分析评价。结果表明,该方法的线性关系良好,相关系数(r)为0.9969～1.0000,检出限为0.1～10μg/kg,加标回收率为86.8%～113.6%,精密度为1.1%～5.7%,方法简便、快速、准确、适用化妆品中元素的测定。146批实际样品测定,汞、铅、砷、镉4种元素以及16种稀土元素安全状况良好,镍(Ni)、铬(Cr)、钡(Ba)三种禁用组分及其盐存在一定的的安全风险,2批样品可能存在原料重金属污染,建议开展镍(Ni)、铬(Cr)、钡(Ba)及其盐的限度研究和加强对化妆品原料中元素的分析与风险评估。     

ICP-MS同时测定绿茶中多种元素含量

建立了微波消解-电感耦合等离子体质谱仪(ICP-MS)同时测定绿茶中Cr、Cu、As、Ba、Hg、Pb 6种元素的含量。绿茶样品经HNO₃-H₂O体系微波消解,利用ICP-MS在KED模式下检测。结果表明,该方法测得各元素线性相关系数(r)均大于0.999;各元素检出限为0.001～0.007 2 mg/kg;各元素相对标准偏差(RSD)在0.26%～7.34%。采用绿茶标准物质对该法进行方法验证,Cr、Cu、As、Ba、Hg、Pb元素的测定值均在标准值区间内。本实验建立的ICP-MS测定重金属元素的方法具有操作简单,灵敏度高,测试结果准确等优点,为消费者了解绿茶品质和选茶提供科学依据。     

微波消解-ICP-MS法测定大米中10种重金属的方法

建立了大米中Pb、Cd、Cr、As、Hg、Cu、Zn、Fe、Mg、Mn 10种重金属元素同时测定的分析方法。用高压密闭微波化学工作站消解大米干样,采用电感耦合等离子体质谱(ICP-MS)测定大米中的10种重金属元素。标准曲线的线性范围在0~100.0μg/L之间,回归方程的相关系数皆大于0.998,方法的检出限均小于0.17μg/L,精密度RSD在1.2%~5.0%之间,对大米标准物质GBW10043(GSB-21辽宁大米)和GBW10045(GSB-23湖南大米)的验证分析,测定值均在保证值范围内。该方法快速、准确、可靠、灵敏度高,可满足同时检测大米中10种重金属元素含量的要求。     

微波消解-ICP-MS测定彩妆类化妆品17种禁用重金属元素

考察彩妆类化妆品中锑、砷、铍、铬、钴、镍、钒、金、铅、硒、锶,蹄、铊、汞、镉、钡、钕17种禁用重金属元素的残留量。建立用微波消解-电感耦合等离子体质谱仪(ICP-MS)同时测定彩妆类化妆品中17种重金属的方法。针对分析过程中基体效应质谱干扰,在MS/MS模式下,向碰撞反应池通入氦气,采用质量碰撞消除质谱干扰,同时在线引入锂、钪、铋、铟、锗、铑作为内标校正基体效应,稳定质谱信号。结果表明,在优化仪器的条件下,各元素线性关系良好,相关系数均大于0.999,检出限范围：0.015mg/kg～0.0427 mg/kg;精密度范围：1.2%～6.1%;加标回收：91.2%～108.0%。结论：该方法具有灵敏度高、简便、同时测定的特点,能准确测定彩妆类化妆品重金属元素含量。     

土壤和沉积物重金属测定中不同前处理和分析方法的比较

采用HNO_3-HCl-HF-HClO_4和HNO_3-HCl-HF-H_2O_2 2种酸消解体系,微波消解和石墨消解两种方式对样品进行前处理,ICP-OES、ICP-MS和AAS三种测定方法对土壤和沉积物标准品中重金属进行测定,结果表明,HNO_3-HCl-HF-HClO_4体系可以使样品完全分解,所有样品中6种元素的测定值与标准值吻合良好,而HNO_3-HCl-HF-H_2O_2体系,微波消解不能用高氯酸,导致6个元素中Mn元素测定值与标准值相比严重偏低,其他元素测定值略微偏低,但在标准值偏差允许范围内。全自动石墨消解仪与微波消解仪相比自动化程度更高,准确度更高,ICP-OES、ICP-MS和AAS均可对土壤和沉积物进行准确测定,不同实验室可根据自身硬件条件选择不同的分析方法。     

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。