水质监测用汞质量控制标准物质的研究

研制了国家级水质汞标准物质,用作汞测定分析的质量控制标准。依据国家标准样品工作导则的技术要求,制备汞标准物质;采用原子荧光光谱法对样品进行均匀性和稳定性研究;以多个实验室协作分析定值的统计结果确定标准值,并进行不确定度评估。经检测汞标准物质均匀性良好,稳定性可达36个月以上;样品量值准确,与美国同种标准物质进行比对具有可比性。研制的汞标准物质符合国家标准物质的技术要求,标准编号为GSB07-3173—2014;可用于水质汞元素检测的质量控制,分析方法研究以及分析实验室能力验证等方面。     

水质监测用汞质量控制标准物质的研究

研制了国家级水质汞标准物质,用作汞测定分析的质量控制标准。依据国家标准样品工作导则的技术要求,制备汞标准物质;采用原子荧光光谱法对样品进行均匀性和稳定性研究;以多个实验室协作分析定值的统计结果确定标准值,并进行不确定度评估。经检测汞标准物质均匀性良好,稳定性可达36个月以上;样品量值准确,与美国同种标准物质进行比对具有可比性。研制的汞标准物质符合国家标准物质的技术要求,标准编号为GSB07-3173—2014;可用于水质汞元素检测的质量控制,分析方法研究以及分析实验室能力验证等方面。     

水质检测用水中苯胺分析校准标准物质的研究

研制了国家级苯胺分析校准用标准物质,作为水中苯胺测定的检测标准。严格按照《国家标准样品工作导则》的技术规范,以重量法和容量法制备苯胺分析校准用标准物质;采用国家标准分析方法气相色谱法对样品进行均匀性和稳定性研究,并进行不确定度评估。经检测,苯胺分析校准用标准物质均匀性良好,稳定期可达36个月以上。样品量值准确,与美国同种标准物质进行比对具有可比性。结果表明,样品的均匀性和稳定性指标符合国家级标准物质的技术要求,样品的标准值及扩展不确定度为100 mg/L和±2 mg/L。样品已获批准为国家级标准物质,可作为环境及相关研究中苯胺测定的工作标准,同时可用于水中苯胺监测的质量控制、分析方法研究的精密度考察、国家实验室能力认可等方面。     

水质检测用水中苯胺分析校准标准物质的研究

研制了国家级苯胺分析校准用标准物质,作为水中苯胺测定的检测标准。严格按照《国家标准样品工作导则》的技术规范,以重量法和容量法制备苯胺分析校准用标准物质;采用国家标准分析方法气相色谱法对样品进行均匀性和稳定性研究,并进行不确定度评估。经检测,苯胺分析校准用标准物质均匀性良好,稳定期可达36个月以上。样品量值准确,与美国同种标准物质进行比对具有可比性。结果表明,样品的均匀性和稳定性指标符合国家级标准物质的技术要求,样品的标准值及扩展不确定度为100 mg/L和±2 mg/L。样品已获批准为国家级标准物质,可作为环境及相关研究中苯胺测定的工作标准,同时可用于水中苯胺监测的质量控制、分析方法研究的精密度考察、国家实验室能力认可等方面。     

水中三硝基甲苯质量控制标准物质的研制

研制了以三硝基甲苯为主要成分的水质计量用标准物质。用先密后疏的方式检验样品的稳定性,对样品的均匀性、稳定性分别采用单因素方差分析方法和线性模型进行考察,组织多个国内权威实验室对样品进行协作分析定值,并对定值结果进行合成标准不确定度和扩展不确定度评估。样品的定值结果为0.983 mg/L,扩展不确定度为0.046mg/L。均匀性指标符合国家标准物质的技术要求,稳定性可达24个月以上。可满足水质三硝基甲苯分析量值传递的需要,达到分析测试中质量保证的目的和要求。     

水环境监测用钒质量控制标准样品的研制

制备和研究了水质监测用钒标准样品,介绍了样品的制备方法,包括比对验证、均匀性和稳定性检验、分析定值和测定数据的统计检验等。用称量法制备样品,以GB/T 5750.6—2006电感耦合等离子质谱法对样品进行均匀性和稳定性研究,并进行不确定度评估。结果表明,钒标准样品的均匀性良好,至少可稳定24个月以上;标准值为0.234 mg/L,相对扩展不确定度为3.4%(k=2),国家标准样品编号为GSB 07-3175—2014。     

水污染监测用水中苯胺标准样品的研究

研制了水污染监测用水中苯胺标准样品。介绍了研制方法,包括试剂的验证、均匀性和稳定性检验、分析定值和测定数据的统计检验等方面。采用重量法制备,用国家标准分析方法《苯胺重氮偶合分光光度法》对样品进行均匀性和稳定性研究,并进行不确定度评估。结果表明,苯胺标准样品的均匀性良好,至少可稳定36个月以上;标准值为1.02mg/L,相对扩展不确定度为3.9%(k=2)。     

锡铸态光谱单点标准样品的研制

锡铸态光谱单点标准样品的研制,根据新的国家标准,增加硫、银、镍、钴四个杂质元素。结果表明:标准样品均匀性、稳定性良好。经国内多家权威实验室和专门从事锡产品检测的实验室协作定值及统计处理,确定了标准值及不确定度,研制技术水平已达到国际先进水平。     

饮用水中铝污染检测分析校准标准物质的研究

根据环境监测和相关分析检测对铝标准物质的实际需求,研制了饮用水中铝污染检测分析校准标准物质。遵循国家标准物质的技术要求,对样品的包装、样品保存介质进行分析和优选。以经过纯度分析的高纯金属铝制备标准物质,对所制备的铝分析校准标准物质,采用单因素方差法评定均匀性;以先密后疏原则测试考察样品的稳定性。在充分考虑样品标准值误差来源及影响因素基础上,对不确定度进行评定。结果表明,样品的均匀性和稳定性指标符合国家级标准物质的技术要求,样品的标准值及扩展不确定度为500 mg/L和±6 mg/L。可作为水中铝测定的检测标准,满足量值传递的需求。     

饮用水中铝污染检测分析校准标准物质的研究

根据环境监测和相关分析检测对铝标准物质的实际需求,研制了饮用水中铝污染检测分析校准标准物质。遵循国家标准物质的技术要求,对样品的包装、样品保存介质进行分析和优选。以经过纯度分析的高纯金属铝制备标准物质,对所制备的铝分析校准标准物质,采用单因素方差法评定均匀性;以先密后疏原则测试考察样品的稳定性。在充分考虑样品标准值误差来源及影响因素基础上,对不确定度进行评定。结果表明,样品的均匀性和稳定性指标符合国家级标准物质的技术要求,样品的标准值及扩展不确定度为500 mg/L和±6 mg/L。可作为水中铝测定的检测标准,满足量值传递的需求。     

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.     

Many Drugs of Abuse May Be Acutely Transformed to Dopamine,Norepinephrine and Epinephrine In Vivo

It is well established that a wide range of drugs of abuse acutely boost the signaling of the sympathetic nervous system and the hypothalamic–pituitary–adrenal (HPA) axis, where norepinephrine and epinephrine are major output molecules. This stimulatory effect is accompanied by such symptoms as elevated heart rate and blood pressure, more rapid breathing, increased body temperature and sweating, and pupillary dilation, as well as the intoxicating or euphoric subjective properties of the drug. While many drugs of abuse are thought to achieve their intoxicating effects by modulating the monoaminergic neurotransmitter systems (i.e., serotonin, norepinephrine, dopamine) by binding to these receptors or otherwise affecting their synaptic signaling, this paper puts forth the hypothesis that many of these drugs are actually acutely converted to catecholamines (dopamine, norepinephrine, epinephrine) in vivo, in addition to transformation to their known metabolites. In this manner, a range of stimulants, opioids, and psychedelics (as well as alcohol) may partially achieve their intoxicating properties, as well as side effects, due to this putative transformation to catecholamines. If this hypothesis is correct, it would alter our understanding of the basic biosynthetic pathways for generating these important signaling molecules, while also modifying our view of the neural substrates underlying substance abuse and dependence, including psychological stress-induced relapse. Importantly, there is a direct way to test the overarching hypothesis: administer (either centrally or peripherally) stable isotope versions of these drugs to model organisms such as rodents (or even to humans) and then use liquid chromatography-mass spectrometry to determine if the labeled drug is converted to labeled catecholamines in brain, blood plasma, or urine samples.     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.